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O rder N u m b er 9111628

Factors affecting herbicide application rates as reported by
no-till corn farmers in nine M ichigan counties
Ndukwe, Ernest Amarachukwu, Ph.D.
Michigan State University, 1990

UMI

300 N. Zeeb Rd.
Ann Arbor, MI 48106

FACTORS AFFECTING HERBICIDE APPLICATION
RATES AS REPORTED BY NO-TILL CORN
FARMERS IN NINE MICHIGAN COUNTIES

By

Ernest Amarachukwu Ndukwe

A DISSERTATION
Submitted to
Michigan State University
in partial fulfillment of the requirements
for the degree of
DOCTOR OF PHILOSOPHY
Department of Resource Development
College of Agriculture and Natural Resources
1990

ABSTRACT
HERBICIDE APPLICATION RATES BY NO-TILL
CORN FARMERS IN NINE MICHIGAN COUNTIES
AND FACTORS INFLUENCING HERBICIDE
APPLICATION RATES
By
Ernest Amarachukwu Ndukwe

This
by no-till
were

the

study

explored

corn farmers

leading

herbicide

application

rates

in nine Michigan counties which

no-till

corn

counties

in

1987.

Each

county had 10,000 or more acres of no-till corn.
The study's purpose was to
or not farmers apply herbicides

(1) determine whether

according to recommended

rates on container labels and what factors influence the
rates

of

farmers
till

herbicides

applied;

apply the same rates

(2)

of

education,

environmental
continuous

land

awareness,

no-till

corn

if the

of herbicides

and conventional-till corn

levels

determine

and

to their no­

(3) the extent that

ownership,

income,

same

farming

farm size,

status,

and years in

influence the

rate of herbicide

consisted

376

applied by the farmers.
The

population

of

no-till

corn

farmers compiled from names provided by the District Soil
Conservationists

in

the

counties

selected.

A

survey

Ernest Amarachukwu Ndukwe

questionnaire was used to gather information.

Ninety-two

valid

in

responses

response

rate.

were

received,

There

were

resulting

72

returned,

but

a

30%

invalid,

responses.
The survey indicated that all respondents applied
herbicides

mostly

below

recommended

rates.

The

metolachlor,

and

conventional
analysis
of

herbicides

also

in

found

farmland,
awareness,

rates

alachlor

significant

applied.
no-till

that

and

level

no

of

herbicides

years

the

respondents

corn

in

most

cases

herbicides applied.

of

range

atrazine,
to

to each other.
differences
were

and

A t-test

in the

no

of

cyanazine,

no-till

education,

rates

significant

till.

It

was

ownership

of

and the farmer's environmental
influence

applied.
have
did

the

conventional

apparent

rates

of

There

farming status,
had

within

applied

tillage conformed

evaluated

differences

and

Finally,

practiced
not

on

the
the

reported
number

continuous

influence

the

of

no-till

rates

of

DEDICATED TO MY PARENTS

MR. SILAS A. NDUKWE
AND
MRS. AUGUSTA N. NDUKWE

The
principles

older
they

have

I

get,
always

the

more

espoused.

I

cherish

Those principles

are truth, honesty, and goodwill toward everyone.

iv

the

ACKNOWLEDGMENTS

No

single

individual,

including

the

author,

can

realistically take all the credit for the completion of a
doctoral

dissertation.

I

wish

to

thank

the

following

people for their assistance:
Dr.

Eckhart

Development,

Michigan

Dersch,
State

Professor,

University,

Resource

chairperson

the guidance committee and my academic advisor,

of

for his

support and guidance throughout my doctoral studies.
Dr.

James

Soil Science,
of

the

the

Kells,

committee,

development
and

research"

Professor,

Crop

and

Michigan State University, who as a member

guidance

critique

Associate

of

the

feedback

(Chapter

was

particularly

survey

especially

IV)

was

helpful

questionnaire.
in

most

the

"heart

valuable

His
of

and

in

the

highly

appreciated.
Dr.

Donald

Meaders,

Extension Education
as

a

member

advisor
provided

in

of

the

(AEE)

the

Agricultural

and

Michigan State University,

who

guidance

author's

valuable

Professor,

minor

feedback

in

committee
field
this

the choice of some of the coursework.

v

of

study

and

academic

studies

(AEE),

as well

as

in

Dr.

George

Development,
the

Michigan

guidance

author's

Axinn,
State

committee.

Professor,

University
His

and

what

would

different

culture

be

and

a member

understanding

cultural background was important

ascertain

Resource

relevant

and

environment

of

the

in helping to

applicable

with

of

regard

in

to

a

this

study.
Dr.

Raymond

vlasin,

Development,

Michigan

accepted

fill

to

sabbatical
India.

Dr.

in

State
for

Professor,

University
Dr.

G.

as the United Nations

Resource

who

Axinn

graciously

who

was

on

(FAO) representative in

Vlasin's thorough review of the dissertation

and his encouragement will always be appreciated.
Dr.

Frank

Fear,

Professor,

Resource

Development

and Chairperson of the Department of Resource Development
who

contributed

to

the

design

of

the

survey

questionnaire.
Dr.
Wisconsin,

Peter
for

Nowak,

encouraging

Professor,
me

to

University

pursue

my

of

research

interests.
Mr. Dwight Quisenberry,
Agronomist
also

with

the

contributed

questionnaire

as

U.S.

Soil

to

the

well

as

former State Conservation
Conservation
design
the

provision

information such as no-till in Michigan.

vl

of

Service
the
of

who

survey
vital

Mr.
research
Urban

Joshua

Bagakas,

assistant,

Affairs

provided

Office

Programs,

assistance

doctoral

of

Research

Michigan

on

candidate
and

State

statistical

and

Evaluation,

University,

data

analysis

who
and

interpretation.
The
the

list

nine

of

District

no-till

corn

Conservationists
farmers

in

the

who

provided

nine

counties

studied.
The

University

Housing

University whose graduate

Programs,

Michigan

assistantship was

State

instrumental

in sustaining me throughout my doctoral work.
The Department of Resource Development,

Michigan

State University, for granting me fellowship awards.
The
and

my

author's

parents,

brothers

and

Mr.

and Mrs.

sisters,

Silas

Ndukwe

Uchenna,

Amaka,

Maduabuchukwu, Chinwe, Azuka, Oluchukwu, Nonye, and Ngozi
for their psychological and emotional support.
John
untimely

death

dissertation
another
the

D'cruz,
by

which

colleague,

comprehensive

a

a

colleague

drunken
was

and

driver

close

to

I studied

examination.

and
put

friend
to

an

whose
end

completion.
together

This

completed six months after John's death.

at

his

John,

times

for

dissertation

was

Ironically, his

death somehow served as the final catalyst in completing
this dissertation.

It was as if I owed it to John.

vii

The

office

of

Affirmative

Action

Graduate

Financial Assistance Program at Michigan State University
for their financial support towards the completion of my
research.
Finally,
excellent

I

wish

to

and

instilling

health

thank

indispensable characteristics
of

this

dissertation

as

God

for

in

granting

me

all

me
the

crucial for the completion
well

as

years

of

formal

education.
Usually in science and in higher education, there
is

a

tendency

to

contribution.
fortunate

and

(Amarachukwu),
language),
(Amara).

be

shy

However,
blessed
when

means

I

in

acknowledging

believe

so may

translated

God's

in

mercy;

I

ways.
from
God

have

God's

been

very

My middle

name

Ibo
(Chukwu)

(a

Nigerian
and

mercy

All of my hard work would have been fruitless

without mercy, guidance, and blessing from the Almighty.

viii

Table of Contents

Page
LIST OF TABLES........................................ Xii
LIST OF FIGURES........................................ xv
I.

INTRODUCTION...................................... 1
Scope of the Problem........................... 6
Statement of the Problem....................... 9
Study Objectives.............................. 10
Research Questions............................ 11
Organization...................................12 .
Significance...................................12
Area of Study................................. 13
Definition of Terms........................... 19
Conventional or Clean Tillage.............. 19
Conservation Tillage........................19
Herbicide....................................19
No-Till or Zero Tillage.....................19
Pesticide.................................... 20

II.

HERBICIDES/PESTICIDES............................ 21
Historical Development........................ 21
Trends in Use (Pesticides)................... 23
Economic importance of Pesticides............ 26
Economic Impact of Restricting
Pesticide U s e ............................... 30
Environmental Impacts of Pesticide U s e ...... 37
Factors that Determine the Movement
of Pesticides in the Environment........... 54
No-Till (NT) Compared to Conventional
Tillage (CT)................................ 60
Definitions................................. 60
History and Trends in No-Till................ 61
Trends....................................... 62
Factors Attributed to the Rise in
Interest in No-Till......................... 63
Characteristics of No-Till Farmers........... 63
Advantages of No-Till.......................65
Theory of Self-Interest.......
69

ix

Page

Chapter
III.

DESIGN OF THE STUDY............................. 71
The Population and Its Selection............. 71
Instrumentation................................72
Administration and Return
of Questionnaires........................... 73
Data Analysis.................................. 75

IV.

PRESENTATION AND ANALYSIS OF D A T A ..............

83

Introduction.................................. 83
General Characteristics andObservations
83
Research Question
1 ......................... 99
Research Question
2 .......................... 105
Research Question
3 .......................... 107
Research Question 4 .......................... 110
Reserach Question
5 .......................... 113
Research Question.. 6 .......................... 113
Research Question.. 7 .......................... 115
Research Question.. 8 .......................... 121
Research Question.. 9 .......................... 123
V.

SUMMARY, CONCLUSION, DISCUSSION, AND
RECOMMENDATIONS................................126
Summary........................................ 126
Purpose...................................... 126
Research Questions.......................... 126
Population and Sample....................... 127
Methodology............................... 128
Size of Fa r m .................................128
Years in No-Till C o r n ....................... 129
Most Common Soil Textures.................. 129
Ownership of No-Till Acr e s................. 129
Are More Herbicides Applied
In No-Till than in Conventional Till?... 129
Summary of the Findings and Conclusions
130
Comparison Between Actual Rates of
Applied Herbicides and the
Recommended Rat e s......................... 130
Comparison Between Rates of Herbicide
Applied in No-Till Corn and Rates
of Herbicide Applied in Corn Under
Conventional Tillage......................131
X

Page

Chapter

Influences of Selected Demographic
Variables on Applied Herbicide Rates.... 132
Discussion..................................... 137
Sources of Information...................... 138
Educational Level Impact.................. 139
Impact of Tenure........................... 140
Income and Its Impact......................140
Impact of Full-time and
Part-time Farm W o r k ....................... 142
Impact of Farm Siz e ......................... 142
Considerations for Nonrespondents............ 143
Limitations and Recommendations for
Future Study.................................145
Recommendations................................146
Generalizability of Study.....................149
APPENDICES............................................. 152
A.
B.
C.

Sample Letter to Respondents............... 153
Questionnaires (1988 and1989).............. 155
Further Discussion of theKey Physical
and Chemical Characteristics of
Pesticide Leacheres........................ 17 3

BIBLIOGRAPHY.......................................... 188

xl

LIST OF TABLES
Table

Page

1.1

Herbicides and States of Detection..............7

1.2

1987 Population and Size of the Nine
Michigan Counties Under Study................. 15

1.3

Land Use (1982) in Nine Michigan Counties
Under Study..................................... 17

1.4

Average Annual Temperature and
Precipitation Based on a 30-Year Record

18

2.1

Pesticides Used in Foreign Countries on
Food Exported to the United States............ 39

2.2

Pesticides in Imported Coffee Beans........... 41

2.3

Typical Positive Results of Pesticide
Groundwater Monitoring in the U . S ............. 43

2.4

Pesticides Detected in Groundwater
Supplies in Iowa and Minnesota................ 45

2.5

Number of Lethal Pesticide-Related
Accidents in the U.S. in Different
Years........................................... 52

3.1

Number of Mailed Questionnaires and
Response Rates..................................75

4.1

Range of Acreages and Percentages of
No-Till and Conventional Till Acreage.........84

4.2

Number of Years in No-Till Corn and
Percentage of Responses......................

85

Most Recent Year the Respondents Tested
the Soil in Their No-Till Corn Acreages

86

4.3

xii

Page

Table
4.4

Most Common Soil Textures Identified by
Respondents and Their Percentages............

87

Number of visits and Telephone Calls
to Cooperative Extension or Soil
Conservation Personnel per Mon t h ............

88

Source of Information for Herbicide
Application and Number of Respondents
Indicating "Very Important" for
Each Source...................................

89

Reasons for the Amount of Herbicides
Applied Based on the Number of Respondents
for Each Reason .............................

93

Factors That Would Cause a Reduction of
Use of Herbicides than in the Previous
Year ..........................................

94

Responses to Whether Agricultural
Practices are Significant Sources of
Environmental Pollution Relative to
Other Sources such as industries............

95

4.10

Level of Education of Respondents...........

96

4.11

Number of Respondents Indicating
Whether They Are Full-time or
Part-time Farmers .................

37

Income Levels of Respondents and the
Number and Percentage of Respondents
in Each Income Level .........................

98

4.5

4.6

4.7

4.8

4.9

4.12

4.13

Most Frequently Applied Herbicides and
the Number of Respondents Applying the
Herbicides in No-Till and Conventional
Till Corn...................................... 100

4.14

Common and Trade Names of the Most
Frequently Applied Herbicides
Identified by the Respondents................ 101

xiii

Table

Page

4.15

Comparison Between Actual and
Recommended Herbicide Rates and
Comparison Between No-till and
Conventional Till Applications.............. 102

4.16

T-Test Result for the Difference
Between Herbicide Application Rates
in No-Till and Conventional Tillage.........106

4.17

T-Test Result: Active Ingredient by
Level of Education:
No-Till O n l y ........... 108

4.18

T-Test Result: Active Ingredient
by Level of Education:
Conventional
O n l y .......................................... 109

4.19

ANOVA Results of Herbicides by
Ownership (No Till Only).....................Ill

4.20

ANOVA Results of Herbicides by
Ownership (Conventional Only)............... 112

4.21

T-Test Result: Herbicides by Farming
Status (No-Till Only)........................ 114

4.22

T-Test Result: Herbicides by
Environmental Awareness (No-TillOnly)

116

4.23

T-Test Result: Herbicides by
Environmental Awareness (conventional
Only)......................................... 117

4.24

One-Way Analysis of Variance Result of
Herbicides by Income (No-Till Only)......... 119

4.25

ANOVA Results by Herbicides by Income
(Conventional Only).......................... 120

4.26

Relationship Between Herbicide Rates
with Size of Fa r m ............................ 122

4.27

Relationship Between Herbicide Rates
with Continuous No-Till C o r n ................ 124

xiv

LIST OF FIGURES
Figure

Page

1.1

Sources of Groundwater Contamination........... 4

1.2

The Nine Counties Studied...................... 14

2.1

Effect of Higher Costs on Supplies
and Price, Without Support Prices and
Acreage Restrictions........................... 34

2.2

Factors Influencing the Behavior and
Export of Agricultural Chemicals From
an Agricultural Watershed......................57

2.3

Processes and Factors which Determine
the Concentration of Pesticide Available
for Runoff From Agricultural L a n d ............. 58

XV

CHAPTER I
INTRODUCTION

Among the environmental concerns recently gaining
attention

in

contamination

the
by

United

States

agricultural

from pesticides and fertilizers.
United

States

targets

of

groundwater

environmental
1986).

Office

is

groundwater

chemicals,

particularly

A report issued by the

Technology

contamination

concern

for the

Assessment
as

rest of the

The Environmental Protection Agency

pollution

by pesticides

urgent problems.

at the top of its

(OTA)

the

primary

1980s

(Tevis,

(EPA) has put
list of most

Consequently, the control of pesticides

already in commercial use was ranked as the topmost major
issue confronting the EPA (Shabecoff, 1986).
Scientists,

environmentalists,

and

the

general

public are concerned about the public health consequences
of pesticides as well as the other environmental effects.
Shabecoff

(1986)

indicated that a number of developments

in

years

have

recent

regulate pesticides.

added

new urgency

to

the need

Among the developments are:

1

to

2

1.

The

discovery that pesticides

in underground water

supplies

despite

are

appearing

an earlier

belief

that they would not pass through the soil.
2.
for

use

The

in

discovery that

the

past

three

some

poisons

decades

can

registered

cause

health

problems such as cancer, mutations, and birth defects.
3.

The

discovery

of

pesticide

residue

in

a

growing number of food products.
4.

A

growing

pesticides

are

hospitals,

and

awareness

used
on

that

inside

huge

homes,

lawns and

farms,

volumes

of

factories,
often

by

and

people

untrained in their use or unaware of their dangers.
5.

Complaints

inadequately

that

protected

farm

from

workers

are

still

pesticides

and

that

widespread illness results.
6.
which

are

The

growing

banned

in

the

export

of

pesticides,

U.S.,

to

developing

where they often arc uncontrolled,

some

of

countries

and may return to the

U.S. on imported foodstuffs.
Furthermore,
EPA
only

has

been

able

Shabecoff
to

provide

(1986)

indicated that the

assurances

of

safety

37 of the more than 600 active ingredients used

for
in

45,000 pesticides on the market and that even at a more
aggressive pace adopted recently,
such ingredients a year.

EPA can only review 25

3

The
farming,

farming

is

the

potentially

largest

a

farmers.

largest

of

source

Until

the

especially

consumer

primary

contamination.
constituted

sector,

the

pesticides
of

of

and

groundwater

197 0 's,

volume

commercial

insecticides

pesticides

used

by

In the early 1980's, herbicides represented 57

percent

of

the U.S.

the

$3.7

billion-a-year

pesticide

market

in

(Hinkle, 1983; Chemical W e e k , 1982).
Contamination of groundwater does not occur only

through farming activities.
activities,
leaks

and

tanks,

such

as

spills,

mining,

It may come from other human

surface

land

impoundments,

disposal

petroleum

and

of waste

natural

landfills,

waters

gas

underground injection wells, and other sources

septic

production,
(EPA 1977)

(see Fig. 1.1).
Groundwater
the

U.S.

percent

because
of

groundwater
Michigan,
private

those

contamination
one-half
who

live

for drinking

about
wells

43
for

of

their

of

a major

the

in

(D'tri

percent

is

concern

population

the

and

in
90

rural

areas

use

and Wolfson,

1987).

In

the

drinking

residents
water

depend

supply

on

(Water

Impacts, November/December 1988).
Environmental,

health,

and other implications of

increased pesticide use have been a major reason for the
recent

upsurge

in

interest

by

scientists

and

4

\

P re c ip ita tio n

\

/

E v a p o tra n s p ira lio n

J

/ T\

D isp o s a l or T p
in jectio n w ell
“well
Landfill d u m p o r /
'
1
1 P u m p in g
L a n d s p r e a d i n g S e p tic t a n k «
refuse pile '
L a g o o n , pit
well
o r irrig a tio n fl n r r e s s n n o l S e w e r x r r r r T T ^ S i r » a i r n f ^ _ P J _ aa-s in

V V
P e rc o la tio n

V

D isc h a rg e

taoie
P e r c o la tio n
L eakage
Leakage
W a te r ta b le aquifer (fre sh )

A r te s ia n aq u ife r (fresh)

Leakage

D isc h a rg e
o r in jectio n
A r te s ia n a q u ife r (salin e)

Figure 1.1
Source:

W.iiei

In ten tio n a l i n p u t
U n in ten tio n al in p u t
Direction of g r o u n d
w ater m ovem ent

Sources of Groundwater Contamination.

Adapted from U. S. Environmental Protection Agency,
1977.

5

environmentalists

for

sustainability

in

agriculture.

Sustainable farming systems have been defined to include:
1.

Systems

that

maintain

and

improve

soil

productivity, quality, and tilth.
2.

Systems

that

augment

the

potential

for

achieving the highest possible efficiency in the use and
conservation

of

basic

farm

resources

(soil,

water,

sunlight, energy, and farmers' time).
3.

Systems

that

interaction as possible:
of

nitrogen

techniques,

fixing
and

incorporate

biological

for example, mulching,

plants,

the

as much

use

the
of

use

of

the use

agroforestry

intercroping

and

crop

rotations to control pests and weeds.
4.
endangering
(some

Systems

instead

minimize

the

use

of

health

and environmentally damaging external

chemical

herbicides,

that

and

the use

fertilizers,
some

nonselective

forms

of

pesticides

energy),

of available affordable,

inputs

and

and

maximize

renewable,

and

contamination

of

environmentally benign inputs, and
5.

Systems

that

avoid

the

groundwater by using only those fertilizers,

pesticides,

and

the

herbicides

that

do not

penetrate

below

plants'

growing zone and then only in controlled doses (Committee
on Agricultural Sustainability, 1987).

6

Scope of the Problem
Increased

of

potential

herbicides

cause

or consumption and potential impacts for surface

material,
increased

labor,

energy,

herbicide use.

potential

crop

application

There

and

time

There

damage

due

is

costs

from

for

contact

contamination.

problems

a

due

groundwater

health

is

concern

and

to

use

direct

concern
arising

for
from

is also the concern for
to

or misapplication.

excessive

Hartwig

herbicide

and Hall

(1980)

noted that pollution of streams, lakes, and adjacent lake
areas

represent

potential

contamination

problems

due

to

herbicide runoff losses.
Herbicides are one source of nonpoint pollution.
Myers et al.

(1985)

construction,

and

important
Myers

et

sources
al.

included agricultural, mining, urban,
silvicultural
of

(1985)

nonpoint
further

sources
pollutants

added

that

as

the

more

nationally.
although

the

principal

sources of nonpoint pollution vary from region

to

and

region

identified

as

state to state,
the

most

agricultural

pervasive

sources were

nonpoint

source

pollutants.
Estimates indicate that more than 100,000 (.08
percent) of the 13 million drinking water wells
in the U.S. may have detectable concentrations of
pesticides that leach into groundwater,
in areas
of vulnerable hydrogeology and heavy agrichemical
use,
as many
as
25 percent
of wells
have
detectable levels of pesticides and 10 percent
have
contamination
levels
above
established
health advisory levels (Fleming, 1987).

7

The

Environmental

Protection

Agency

(EPA,

1984)

indicated that virtually all states in the U.S. have some
water quality problems caused
EPA

(1987)

also

groundwater
crops

and

spills,

can

indicated
occur

subsequent
accidents,

by nonpoint sources.

that

contamination

from

pesticide

leaching

as well

or

from

aircraft

The

of

the

applications
as

from

used

to

chemical
to

spray

pesticides.
As

shown

on

Table

1.1,

Cohen

et

al.

(1986)

reported that "at least" 17 pesticides have been found in
groundwater

in

23

states

as

a

result

of

routine

agricultural practices.

Table 1.1

Herbicides and States of Detection
State(s)

Herbicide
Alachlor

Maryland, Iowa, Nebraska,
Pennsylvania

Atrazine

Pennsylvania, Iowa, Nebraska,
Wisconsin, Maryland

Bromacil

Florida

Cyanazine

Iowa, Pennsylvania

Dirosels

New York

Metolachor

Iowa, Pennsylvania

Simazine

California, Pennsylvania,
Maryland

Adapted from S. Cohen, C. Eiden, and M. Lorder, 1986.

8

Kelly

et

al.

(1986)

showed

that

used pesticides especially herbicides,
groundwater

and

that

several

many

commonly

are leaching into

herbicides,

especially

atrazine, are persisting in groundwater.
Two
revealed

separate

the

studies

presence

of

conducted

atrazine

in

in

Michigan

groundwater.

A

study conducted by the Michigan Department of Agriculture
(MDA)

showed detectable levels of atrazine in 18% of the

50 wells tested.

The MDA study investigated

sites where agricultural chemicals
and

stored"

and

contamination."

"where

the

soil

"commercial

are routinely handled
type was

conducive

to

The MDA study also found nitrates in 25

of the 50 wells tested

(GEM Notes 1989, MDA 1989).

In another study, the Institute of Water Research
(IWR)

at

Michigan

State

levels of atrazine"
IWR

study

counties,

was

1989).
are

conducted

from

Atrazine

widely

used

found

"detectable

in 29% of the 38 wells tested.

focussing

contamination

University

"in

on

predominantly

areas

land

use

and

nitrates

and

because

highly

agricultural

vulnerable

activities"
were
they

The

(GEM

tested
have

Notes,

because

been

to

they

found

to

contaminate groundwater in other states.
Lee
live

and

and

Nielsen

consume

mostly

contamination

potential

likely

the

incur

(1987)

from

highest

stated

that

groundwater
agriculture

costs.

These

is

people

who

where

the

high

will

costs

include

9

monitoring
effects,

and

detection

installation

of

activities,

water

adverse

filters,

and

health

the use

of

bottled water.
Statement of the Problem
A

report

by

the

State

of

Michigan

Governor's

Cabinet Council on Environmental Protection (1985) stated
that approximately 92 percent of Michigan's land area is
classified as rural.
water
in

According to the Report, nearly all

pollution originating

source

and

activities.

comes

The

from

Report

from rural land
various

further

types

stated

is nonpoint
of

land

that the

use
most

serious nonpoint pollution source originates from area of
intense

agricultural

significant
sediment,
as

the

areas

pollutants

nutrients,

major

soils

urban
from

uses

of these

insufficient

most

sources

are

Cropland was noted

pollutants,

by high density

where

and that the

agricultural

and pesticides.

source

characterized

textured

and

especially

row crops

attention

in

and fine-

is

paid

to

soil conservation and drainage practices.
The

report

furthermore

listed

pollution control.
1.

by

the

the

Governor's

benefits

Cabinet

of

nonpoint

source

They include:

Protection

of

soil

resources

base for

and fiber production
2.

Council

Protection of drinking water supplies

food

10

3.

Protection of aquatic ecosystems

4.

Protection of commercial and sports fisheries

5.

Enhanced recreational activities

6.

Reduced

damage

to

drainage

and

water

treatment facilities
7.

Protection

of

water

storage

and

navigation

Natural

Resources

facilities
A

Michigan

publication
Michigan's

Department

(1986)

indicated

residents

of
that

nearly

one-half

of

rely on groundwater as their source

of drinking water while many communities, and probably 95
percent

of

rural

families,

are

served

by

groundwater

wells.
It is well documented that herbicide use was been
on the increase over the years.
farmers'

purchase

ingredient)
it

is

herbicides

increased by 140%

not

strictly

of

Between 1966-1980,
(pounds

(Eichers,

known

if

farmers

are

according

to

recommended

of

1981).

applying

U.S.

active
However,

herbicides

application

rates

on

herbicide container labels.

Study Objectives
The
determine

primary
if

no-till

objective
corn

of

farmers

this
in

study
nine

is

to

Michigan

counties are applying herbicides according to recommended
application rates.

11

A

second

objective was

to determine

if the same

farmers apply the same rate of herbicides to both no-till
and conventional-till corn acreages.
of this
such

study was

as

income,

environmental

The third objective

to determine whether certain factors,
level

awareness,

of

education,

and

land

farming

ownership

status,
have

any

influence on the perceived rates of herbicides applied by
the farmers.
Research Questions
Based

on

the

study

objectives,

the

consequent

research questions are:
1.

To what extent do herbicides applied by no-till
corn farmers in nine counties of Michigan conform
with the recommended rates on container labels?

2.

To what extent do herbicide rates applied by the
same no-till corn farmers conform with herbicide
rates they apply on conventional till corn acres?

3.

To what
extent does the level
of education
influence the rate of herbicides applied by the
farmers in no-till and conventional till corn?

■1. To whal extent does ownership
or rental of
farmland influence the rate of herbicides applied
by the farmers in no-till and conventional till
corn?
5.

To what extent does farming status
versus
part-time)
influence
the
herbicides applied in no-till corn?

(full-time
rate
of

6.

To
what
extent
do
farmers'
environmental
awareness influence the rate of herbicides they
applied in no-till and conventional till corn?

7.

To what extent does income influence the rate of
herbicides applied by the farmers in no-till and
conventional till corn?

12

8.

To what
extent
does
the
size
of the
farm
influence the rate of herbicides applied in no­
till and conventional till corn?

9.

To what extent do years in continuous no-till
corn influence the rate of herbicides applied?

Organization
In

addition

objectives

and

previously

of

development,

use,

characteristics

Chapter

in

history
of

of

Chapter

and

trends

scope of the problem,

description

terms.

herbicides

pesticide

the

discussed,

definition
about

a

to

the
I

also

II

no-till

an

their

trends

farmers.

study

in

a

insight

historical

environmental

and

of

includes

provides

pesticides,
use,

area

study

impacts
no-till

Chapter

II

of
and
also

compares no-till and conventional.
Chapter

III

outlines

the

design

of

the

including the population and instrumentation used
study.

study
in the

Chapter IV reports the presentation and analysis

of data and Chapter V includes the summary,

conclusion,

discussion, and recommendations for future study.
Significance
This study is significant because it has not been
previously

determined

whether

farmers

herbicides based on the recommended rates

are

applying

(Nowak,

This study will shed some light on issues such as:

1987).

13

1.

what

the

farmers

are

doing

in

terms

actual herbicide rates they apply

of

the

(in active

ingredients);
2.

whether

there

between

the

no-till

and

is

a

rates

significant

of

difference

herbicides

conventional-till

applied

corn

by

to
the

same farmers who raise both;
3.

where

the

farmers

get

their

information

on

the rates of herbicides they apply; and
4.

whether

the

practices

farmers

in

their

perceive
locality

agricultural

as

a

source

of

environmental and health concerns.
Area of Study
The study area for this research is the southern
portion of Michigan's lower peninsula.
composed
Eaton,

of

nine

counties:

Hillsdale,

Ingham,

(Fig.

1.2).

The

ranks

in the

state

Berrien,

Ionia,

population

The study area is

of

Isabella,
the

were

chosen because

no-till

corn-producing

(Quisenberry, 1987).

Clinton,

and

counties

are shown on Table

counties

Cass,

1.2.

Lenawee

and

their

These nine

they were the nine primary

counties

in

the

state

in

1986

Each of the nine counties had more

than 10,000 acres of no-till corn in 1986.
The
cropland,

major

forest,

land
and

use

in

the

nine

counties

other land which includes land

are
in

14

NO-TILL CORN - 1986

ACRES

Figure 1.2
Source:

The Nine Counties Studied

(Shaded in Black).

U. S. Department of Agriculture, Soil Conservation
Service, 1987.

15

Table 1.2.

County

1987 Population and Size of the Nine Michigan
Counties Under Study

Population
(1987)

County
Population
Rank in State
(83 Counties)
(1987)

Rank in
Size
(83
Counties)
(1987)

164,800

11

40

Cass

48,300

35

73

Clinton

56,400

29

42

Eaton

91,900

19

37

Hillsdale

42,800

36

36

279,600

6

57

Ionia

54,700

31

38

Isabella

53,600

32

39

Lenawee

89,300

20

23

Berrien

Ingham

Source:

Michigan Department of Agriculture, 1988.

16

buildings,

roads,

streets,

forest (MDA, 1988)
Berrien

County

wasteland,

(see Table 1.3).

(39.8

percent)

and

noncommercial

Cropland is least in

and

highest

in

Lenawee

county (66.7 percent) among the nine counties.
The topography of most of the counties, including
Hillsdale, Lenawee, Berrien, Cass, Clinton, Eaton,
and

other

counties

characterized
with
and

the

by

in

"glacial

highest

features

elevations

interlobate moraines,

outwash channels,

Southwest

("Hydrogeology

Control,"

1981).

The

Michigan

and

associated

drainage
with

are
systems

recessional

and the lower elevations with

outwash plains,

plains"

Ingham

for

lake plains,
Underground

range of elevations

and till
Injection

in the region

is from 577 feet on Lake Michigan to about 1282 feet at
Budday

Hill

in

Hillsdale

County.

The

hydraulic

characteristics of glacial drift aquifers result in well
depths
feet

ranging

from

18 feet in Van Buren County to

in Ingham County.

bedrock

aquifers

Pennsylvanian

in

aquifers

422

The hydraulic characteristic of
the

region

dominate

most

indicate
of the

region

that
and

supply the largest number of bedrock wells ("Hydrogeology
for Underground Injection Control,"

1981).

The depth of

bedrock wells in the region range from 46 feet in Lenawee
County

to

525

in

Clinton

County

Underground Injection Control," 1981).

("Hydrogeology

for

17

Table 1.3.

County

Land Use (1982) in Nine Michigan Counties Under
Study

Total
County
Acreage
(in
Acr e s )

Cropland

Pasture

Forest

Water

Other
Land

Berrien

368,704

39.8

2.6

17.9

0.7

39.0

Cass

317,580

43.8

6.6

17.0

2.9

29.7

Clinton

366,764

58.1

3.8

8.3

0.3

29.5

Eaton

370,745

48.9

5.7

12.3

0.2

32.9

Hillsdale

385,862

51.0

5.2

11.7

0.6

31.5

Ingham

358,214

49.1

3.8

11.8

0.2

35.1

Ionia

369,299

50.5

5.2

10.1

0.6

33.6

Isabella

369,017

40.6

5.5

21.2

0.2

32.5

Lenawee

481,625

66.7

3.1

9.9

1.2

19.1

Source:

Michigan Department of Agriculture, 1988.

18

The average
counties

under

study

precipitation,
snowfall,

is

rainfall

and

annual monthly temperature of the nine

which
34

is

inches

snowfall

Michigan," 1974)

is

in

48

F.

subdivided
and

46

the

The
into

inches,

nine

average

annual

rainfall

respectively

counties

("Climate

(see Table 1.4).

Table 1.4.

Average Annual Temperature and Precipitation
Based on a 30-Year Record (1940-1969)

County

Temperature

Rainfall

Snow, Ice

Berrien

49.4

35.7

57.8

Cass

49.4

36.8

63.3

Clinton

47.7

30.3

37.4

Eaton

47.8

32.4

38.3

Hillsdale

48.1

36.5

52.7

Ingham

47.4

30.9

38.8

Ionia

47.7

30.6

39.7

Isabella

49.4

35.6

57.8

Lenawee

48.9

32.7

30. 3

AVERAGE

48.0

34.0

46.0

Source:

Climate of Michigan, 1974.

and
for
of

19

Definition of Terms
In order to aid those readers who are unfamiliar
with some of the words or terminology used in this study,
the following definitions have been provided.
Conventional or Clean Tillage
The

combined

operations
a

given

primary

and

secondary

tillage

normally performed in preparing a seedbed for
crop

growing

in

a

given

geographical

area

(Resource Conservation Glossary RSG, 1982).
Conservation Tillage
Any tillage sequence that reduces loss of soil or
water

relative to conventional

noninversion

tillage

tillage,

that retains

often

protective

a form of
amounts

of

residue mulch on the surface.
Herbicide
A
plants,

chemical
or

to

used

to

interrupt

control,

severely

suppress,

their

normal

or

kill

growth

processes (Ross and Lembi, 1985).
Goulding
as those products

(1985)

descriptively defined

intended, or employed,

herbicides

for the purpose

of destroying or inhibiting the growth of plants.
No-Till or Zero Tillage
A

method

of

plaiting

seedbed preparation other than

crops

that

involves

no

opening the soil for the

20

purpose of placing the seed at the intended depth

(RCG,

1982).
Pesticide
Any
organisms,

chemical
such

agent used

as

fungicides (RCG, 1982).

for control

insecticides,

of specific

herbicides,

and

CHAPTER II
HERBICIDES/PESTICIDES
Historical Development
Ware (1983) noted that the earliest record of any
material being used as a pesticide is by Homer, the Greek
poet,

who

referred

to

the

burning

of

sulfur

for

fumigation of homes in about 1,000 B.C..
Ross and Lembi

(1985) indicated that weed control

technology had its beginnings about 1900 and
although salt, ashes, smelter wastes, and other
industrial
byproducts
had
been
applied
for
centuries at high rates (and near their source of
supply)
to
control
vegetation,
it
was
the
discovery
of
the
fungicidal
properties
of
Bordeaux mixture that led to the first serious
attempts at chemical weed control.
The discovery
(near Bordeaux, Prance) in 1896 that a limecopper-sulfur mixture would control downy mildew
on grapes led to the extensive testing of this
fungicide and other copper salts for the control
of diseases on a variety of crops.
A major
development effort occurred from 1900 to 1915 in
Prance, Germany, and the United States with most
of the emphasis placed on weed control in cereal
crops.
According
solutions
acid,

to
of

the

National

copper

iron sulfate,

nitrate,

development

and

Council

ammonium

salts,

(1968)
sulfuric

and potassium salts were shown to be

selective herbicides.
the

Research

Ross

and Lembi

extensive use

21

(1985)

noted

of selective

that

chemical

22

controls lapsed after 1915 in the United States while they
were

used

The

extensively

prevalence

which

insured

of

in

Europe

small,

that

the

and

the

intensively

chemicals

British

Isles.

cultivated

would

be

farms

applied

in

a

timely and careful manner was seen as the reason for the
extensive
(1985)

use

noted

these

water

humidity

in

Europe.

that

In

"the penetration

soluble

conditions

salts

were

prevalent

(1975)

suggested

the lapse

after

1915

inadequate

to

addition,

in

Ross

and

Lembi

and effectiveness
favored

these

in the U.S.

by

the

areas."

of

high
Crafts

of the chemicals

spraying

equipment,

large

acreages, low humidity conditions, and the introduction of
cleaner, weed-free seeds and effective fallow systems.
A
between

limited

1900

herbicides

and

number
1940

included

chlorates,

herbicides;

carbon

plants;
the

selective

compounds
World

War

to be used
II,

then,

and

arid

Lembi,

borates
and

sulfamate

for

nonselective

the

first

list

the

introduced

1985).
such
long

These
as

control

group

the

residual

thiocyanates

herbicidal

specific

of

as

the

for weed control.
the

were

compounds,

bisulfide

and

dinitrophenols,

(Ross

herbicides

persistent

arsenicals,

fumigants; ammonium

of

of

woody

oils,
of

as

and

organic

At the start of

available

herbicides

consisted of about a dozen chemicals of somewhat limited
utility.

23

According

to

Ross

and

Lembi

(1985),

development of modern herbicide technology was
by

the

discovery

of

the

herbicidal

(2,-3-dichlorophenoxyacetic
synthesized

in

1941.

The

triggered

properties

acid).

The

compound

was

of

to

be effective

cheap to produce,
addition,

at low rates

and had

"the commercial

2,4-D

herbicide

was

released

for

general investigation and use after World War II.
found

the

It was

(1/4 to 4 lb./acre),

a broad spectrum of uses.
success

of

2,4-D provided

In
the

incentive for the development of several hundred chemical
compounds currently available for weed control."
Trends in Use (Pesticides)
The use of pesticides has been on the

incline since

the discovery of 2, 4-D and since the end of World War II.
Eichers

(1981) noted a 140% increase (in pounds of active

ingredient) in the purchase of pesticide by U.S.A. farmers
between 1966-1980.
a

substantial

products

Maddy

and

(1983)

pesticide

increase

used,

pesticides

Maddy (1983) wrote that there has been

the
the

added

products

ingredients,

and

in

"the

individual
total
that

active

poundage
"more

containing

many

number

times

of

than
more

that

of

pesticide

ingredients

pesticides
45,000
than

number

u s e d ."

individual

1,500
of

in

active

so-called

'inert' ingredients" were registered for use in the U.S.A.

24

Furthermore,

Maddy

(1983)

attributed

the rapid growth in

use of pesticides in the U.S.A. between 1966-1980 to
pesticide prices which rose only half as much as
other inputs, farmers' felt need to protect the
increasing investment required in producing a
crop and due to the increased use of multi­
chemical
products,
tank-mixes,
and
multiple
sequential applications to obtain season-long
weed control and the control of problem weeds.
Wolcott (1988) noted that the use of pesticides, virtually
nonexistent prior to World War II,
$4.5 billion industry
stated

that

in

has burgeoned

(in the U.S.).

1986,

more

than

into a

Wolcott furthermore

500

million

agricultural pesticides were used in the U.S.

pounds

of

The great

majority of agricultural chemical use is for the purpose
of

sustaining

supported
for

yields

by

the U.S.

example,

accounts

of

the basic

government's
for

corn,

wheat,

which

have

(USDA)

rice,

some

price

cotton,

kind

of

support

farm program.

more than

agricultural pesticide use.

commodity

30

crops
Corn,

percent of

all

Six basic commodity crops—
barley,

U.S.
or

and

soybeans— all

Department

of

loan program,

of

Agriculture

account

for

a

combined total of more than 80 percent of the total volume
of agricultural pesticides.

In addition to growth in the

use of agricultural chemicals on the USDA program crops,
there

has

also

been

a

amounts

of

chemicals

produce

and

fruits

chemicals

have

in

sharp
used

increase

on specialty

particular).

been developed,

in

A

not only

the

kinds

crops

wide

(fresh

variety

to combat

and

of

pests

25

and

plant

diseases,

but

also

to

regulate

the

growth

of

fruits and vegetables and enhance the cosmetic appearance
of produce.
A report by the EPA

(1987)

showed that about 552

million pounds of active ingredients were applied to major
field

crops

in

1982

and

approximately

280

million

acre

treatments are conducted annually (EPA, 1987).
D'ltri

and

Wolfson

(1987)

also

noted

that

the

annual total output of pesticides in the U.S. is more than
2.5 billion pounds with 1,500 active ingredients

in some

45,000 products.
In

terms

of

pesticide

use,

Schaub

(1985)

wrote

that:
historically, a common measure of pesticide use
has been pounds of active ingredient
(a.i.)
applied.
Another is number of acres treated and
a third is acre-treatments (which is the average
number of times a pesticide is applied to a given
acre times the number of acres treated.
The
fourth measure of importance is expenditures for
pesticides. With the development of new products
requiring application rates as low as 0.1 lb.
(a.i.) per acre, pounds applied, when used for
historical comparisons, is losing meaning unlike
the more meaningful measures such as of acres
treated. . . .
The use and increased use of farm chemicals,
as pesticides,
food

relates

production

for

such

to the need to increase the world

the

ever-growing

world

population.

Koeman (1985) acknowledged that there are, in general, two
ways

to

achieve

One method

an

increase

in

is by increasing the

agricultural

production.

acreage of arable land,

26

and

secondly,

by

intensification

of production per unit

area.
Ahrens
have

been

and Cramer

used

production.

to

(1985)

counter

Ahrens

and

implied

that pesticides

fluctuations

Cramer

(1985)

in

agricultural

also

noted

that

inclement weather and pests are two main factors that can
be

considered

production

responsible

in

for

agriculture.

great

However,

fluctuation
while

of

inclement

weather is beyond human control, humans have been fighting
against pests,
modern
been

plant

and it is only in the last 50 years, with
protection

successful

technologies,

in bringing

the

that

greatest

humans

problems

have
under

control.

Economic Importance of Pesticides
Yield

losses

can

qualitative.

An

initial

quantitative

losses

for

60

be

both

global
important

quantitative

and

estimate

the

of

crops made

in 1967

concluded that about 35 percent of the potential yield was
lost

through

plant

pests,

such

as

insects,

fungi,

and

weeds (Crammer, 1967).
With a 30 percent reduction of pre-harvest losses
caused

by

animal

pests,

plant

diseases,

and

weeds

developing and centrally planned countries, alone,
been estimated that 100 million tons of additional
would become available (Buchel, 1983).

in

it has
grain

27

The quality
major

concern

farmer,

to

of the

the

agricultural product

farmer

and

the

consumer.

is of a
To

the

it is an issue of marketability of the product,

especially

of

fresh

vegetables.

The

products,
farmer

such

is

as

fruits

and

concerned

about

the

marketability of the product because the consumer or the
processor

is

very

particular

about

the

quality

of

the

goods which, as a rule, is evaluated with respect to size,
perfection,
contained,

and

cleanliness

such as starch,

of

oil,

surface
sugar,

or

substances

and aroma

(Ahrens

and Crammer, 1985).
For

the most

part,

quality

criteria

is

realized

only through the use of plant protection chemicals,

such

as insecticides, fungicides, molluscides, nematicides, and
herbicides
damage,

for

the

prevention

of

direct

and

indirect

such as the reduction of storage life (Ahrens and

Cramer, 1985).
In
shown

an experiment

that

the

deficit

done
or

in apple orchards,
the

insufficiency

it was
of

crop

protection measures had a negative impact on the yield and
marketability
measures,

of

the

fruit.

Without

plant

the yield declined to 57 percent of what would

have been realized with a full-season program,
percentage
criteria,

protection

of

the

fruit

could be graded

which,

on

the

as marketable,

basis

while the
of

quality

dropped to only

28

19 percent of the possible total yield (Kolbe, 1982,

125-

33).
Pesticides
existing
under

crop

serve

production

particular

techniques

can

(Ahrens

as

systems,

circumstances,
and Cramer,

a

means

and

even

new

to

improve

to

create,

crop

1985).

production

For example,

the

production of sugar beets used to be very labor-intensive
because weed competition had to be eliminated over a long
period between seed germination and complete leaf-coverage
of

the

soil.

Previously,

it

required

130

human

labor

hours per hectare from drilling to harvest of which more
than

100

chemical

hours
weed

equipment,
hectare

requires
sugar

Consequently,

required

control

it

of

were

for

practices
less

beet

weeding

today,

than

(Ahrens

30

alone

coupled
hours

and

to

Cramer,

. With

with new
grow

one

1985).

the use of pesticides appears to save time

and labor costs.
Ross

and Lembi

(1985)

outlined

the contributions

of herbicides which are the most widely used pesticides.
The contributions are:
1.

herbicides

permit the control of weeds where

row cultivation is impossible,
2.

herbicides

reduce

the

number

of

tillage

operations, as well as the critical timing needed for such
operations, particularly at planting time,

29

3.
effort

herbicides have reduced the amount of human

expended

in

handweeding

and

consequently

reduced

weeding costs where effective herbicides are applied,
4.
methods

weeds

not

frequently

economically

can

be

controlled

controlled

by

effectively

other
and

at

relatively low cost with herbicides, and
5.

the

flexibility

use

in

Consequently,

of

the

herbicides
choice

farmers

has

of

today

a

can

permitted

management
use

fewer

greater
system.

crops

in

rotation, have the option of removing one or more tillage
or mowing operations,

and eliminate periodic fallow every

three or four years.
In
expenditure
aggregate

the
on

1960's,
pesticides

(Headley,

herbicides

was

estimated

brought

1968).Unlike

recent studies point
pesticide use.

it

toward

have

not

application

a decline

insecticides

1983).

reason,

in

$1
the

studies,

in the

in

corn

returns to

production,

respectively

It was concluded that
returns to

equalled
of

return

a

A study showed that of every $1 spent for

and

more pesticides,

$4

previous

returns were only $1.50 and $1.30,
and Duffy,

a

that

(Hanthorn

as farmers use

expenditure decline. Returns

costs

in

some

pesticides

have

been

in addition

the

to changes

pest resistance (Schaub, 1985).

in

instances.
attributed

pest

Over­
as

the

populations

and

30

Economic impact of Restricting
Pesticide Use
For
pesticide

the

use

purposes

ranges

of

this

study,

from regulation

to

restricting

restricting

the

use of one pesticide to a specific use to a total ban of
all pesticides for all uses.
Between late 1970s and mid-1980s, 25 studies were
completed,

representing

about

35

registered

pesticides

which is a small portion of the total number of registered
chemical pesticides.

It was estimated that the economic

impact

on

producers

excess

of

$6

and

billion

consumers

annually

would

if

all

have
uses

been
of

in

these

pesticides had been cancelled (Schaub, 1985).
Pesticide regulation alone adds up to high private
and public costs.
and develop
1985).
funds

In

1975 the private cost to discover

a pesticide was nearly

For the same period
available

for

$15 million

(Schaub,

(1975), it was estimated that

research

and

development

(R

and

D)

were $320 million annually, of which about 60 percent was
available for new product development, with the remainder
used

to

maintain

the

registration

and

marketability

of

previously registered products (Schaub , 1985).
In 1983 it was estimated that industry spent $450
million
1983).

annually
The

expenditures

for

research

increase
was

in

attributed

and

development

research
to

the

and

(Pliszka,

development

revenue-making

31

capability

of the

industry

and

in 1981

it was estimated

that 67 percent of the expenditure was invested
product development
20

years,

it

registration

has

and

significantly

(Pliszka, 1983).
become

larger

Over the past 15 to

increasingly

environmental

testing

proportion

into new

of

evident
do

that

comprise

the

R

a

and

D

expenditures (Schaub, 1985).
To
extremely

ascertain

public

difficult.

costs

Nonetheless,

public costs of regulation is high.
pesticides

program

of

in

it

regulation
is

agreed

is
that

The financing of the

Environmental

Protection

Agency

(EPA) is estimated to be around $28 million in fiscal year
(FY) 1983, down from about $31 million in FY 1982
of Management and Budget,

1982).

(Office

However, within the EPA

budget was some $230 billion for Management and Support,
some

of

which

presumably

will

be

allocated

to

the

pesticide programs (Schaub, 1985).
One study estimated that banning the use of 2, 4,
5-T

on 8 million acres of farm and nonfarm land in 1969

would have increased costs to farmers about $32 million,
assuming

the

maintained

level

(Fox,

of

1972).

production
It

was

also

at

the

time

estimated

that

was
it

would have cost farmers $44 million to replace 2, 4, 5-T
(Fox, 1972).
It has been shown that the effect of restricting
use

of herbicides is a rise in

costs,

although the total

32

dollar effect on individual farmers depends on the demand
for

individual products

government

programs

and

(Fox,

on whether or not there
1972).

Fox

(1972)

are

indicated

that:
for purposes of budgeting effects of banning
herbicides,
changes
in
the
marginal
costs
(incremental costs) are particularly important
because this cost curve above the minimum average
variable cost is,
in effect, a supply curve
(lines
drawn
from
any point
on this
curve
horizontally or vertically to the price and
quantity
line
show
prices
associated
with
quantities sold).
Increases in the marginal cost
for an individual farmer are the same as a
decrease or shift to the left in the supply curve
for the given product.
(See Figure 2.1)

Consequently,

farmers will produce less

at the same price because of increased costs and because
of

higher

costs,

some

farmers

would

also

go

out

of

business (Fox, 1972).
Cashman
bans

under

et

al.

typical

substantial,

(1981)

Indiana

short-run

concluded

that

conditions

economic

"herbicide

would

losses

on

inflict

individual

farmers" since "g simultaneous ban on all uimiLroamiiine,
triazine,
yields
65%."

14

and
and

Such

attributable
"resulted

amide herbicides
17%,

respectively

reductions
to

less

in a loss

reduced

were

corn

and net

blamed

effective

in efficiency,

on

weed

and

farm

soybean

income

by

"harvest

delays

control"

which

yields,

and profits,

and increased machinery and labor requirements."

33

The industry or market supply curves are generally
similar to the individual farm supply curves,
different

from

since

market

the

generally
change

the

demand

inelastic

in supply

products,

demand

curve

curve

(Figure

and

reductions

the

for

is

individual

negatively

2.1).

As

sloping

a

demand

in supply

but totally
farmers

sloped

result
curve

and

of

for

the
farm

to X2 ) will result in

higher prices paid for farm products (P1 to P 2 )*
Fox

(1972)

postulated

that

with

lower

food

production and higher prices, farmers would often get more
than they got before restriction since the demand for food
is inelastic as there are not good substitutes for food.
Dailey

(1974)

similarly discussed

the effects

of

restricting or banning use of pesticides on the producers,
the industry, the consumers, and general effects.
would

likely

receive

commodities

than

because

demand

the

they
for

more

for

received
food

is

their
before

Farmers

agricultural
a

restriction

inelastic.

Thvis,

the

increase in prices would more than offset any decline in
production.

However,

for

commodities

characterized

by

elastic demand, the increase in price would not be enough
to offset the loss in production (Dailey, 1974).
Dailey
restricting

(1974)

the use

acknowledged that for the industry,
of pesticides

production and distribution costs

would

generally

for pesticides

raise

because

of generally higher costs brought about by a reduced

COST OR PRICE
(D O llA RS)
PRICE

f

W

New Marginal Corf
or
/
Supply
y

/

Naw
Supply /
Old M arginal Cost

Demand

P

0
Qu an t it y

By Individual Farmer

Figure 2.1
Source:

X x
Qu an t it y

For All Farmers

Effect of Higher Costs on Supplies and Price, Without
Support Prices and Acreage Restrictions

A.S. Fox, "Economic Impacts of Restricting Herbicide Use."
Journal of Environmental Quality 1(4) (1972): 439.

35

volume of production.

It was further indicated that some

companies would lose and others would benefit.
in

general,

pesticides

comprise

a

business of most manufacturers.

small

Although,

portion

Consequently,

of

the

losses and

gains would be small in comparison to total sales.
The effect on the consumer of restricting the use
of pesticides was seen as higher costs for food and fiber.
With

regard

banning

to

the

use

specific areas,
regional

the

general

of

effects

pesticides

of

for

restricting

selected

crops

or
in

the impact was seen as resulting to some

shifts

in

production.

In

an

example,

Dailey

(1974) indicated that
long run adjustments from banning organochlorine
could lead to higher costs of producing cotton
particularly in the southeast.
This, plus the
continued pressure from synthetics, might make
the production of corn, soybeans, and cattle or
increased timber production more attractive in
this region.
If the use of organocholorines were
banned, the inducement to grow corn in the south
could be further Increased because of possible
insect problems in the Corn Belt.
Two
national

events

and

in March,

international

1989,

attention

pesticides in agricultural products.
March,

1989,

in

the

to

U.S.

the

brought

dangers

of

In the first week of

the Natural Resource Defense Council

(NRDC)

reported that apples treated with the growth regulator and
ripening agent, Alar, were endangering small children with
dangerously
carcinogen

high
(Carson,

levels
1988).

of

daminozide,

Less

than

a

possible

a week later,

two

36

grapes

imported

from Chile

cyanide.

The

Food

consumers

not

to

Chile.
most

of

raspberries,
disappeared
across

peaches,

melons,
from

the

grapes,

contaminated

any

fruits

to

be

pears,

About

the

and

same

from

grapes,

blackberries,
and

the

time,

with

warned

fruit

including

plums,

markets

laced

(FDA)

other

blueberries,

fruit

U.S.

were destroyed

or

the warning,

the

found

and Drug Administration
eat

Following

were

nectarines

grocery
400,000

stores

chickens

in Arkansas because they were found to be
with

heptachlor,

which

is

an

outlawed

pesticide (DeVault, 1989).
The warnings from the NRDC and FDA highlighted the
potential
cyanide

health
is

sector,

not

hazards
a

of

pesticide

pesticide
used

in

use.
the

Although
agricultural

the scare from the two grapes laced with cyanide

reminded the general public and the federal government, in
particular,

about

proper

monitoring

of

agricultural

products, especially imported fruits and vegetables.
before

the

American
allowed
products.
American

incident

consumers
levels

of

involving
have

the

often

pesticide

cyanide-laced

suspected
on

Long

grapes,

a

higher-than-

imported

agricultural

Such suspicions have often been heightened on
television where

imported

agricultural

products

have been portrayed by some advertisers as travelling less
than desirable
with pesticides.

routes

and being

indiscriminately

sprayed

It is interesting to note that Uniroyal

37

Corporation, the manufacturer of Alar, decided to stop the
production of Alar for use in the U.S.

in May,

to the controversy surrounding the chemical.
such categorical statement was made

1989, due

However, no

regarding its export

or production overseas.
Although

the

television

advertisement

about

imported food items borders on sarcasm, data indicate that
there

are

reasons

Acknowledging
national

that

borders,

approximately
contains
some

10

illegal

hazardous

Americans
2.1).
1978)

are

The

to

be

or

pesticide

pollution

Weir

Shapiro

and

percent
levels

of

not

escaping

General
that

imported

of pesticides

chemicals

indicated

wary

have
the

Accounting
the Pood

(FDA) most prevalently used

been

somewhat
does

(1981)
food
and

and

respect

noted
in

that

U.S.

although
in

effects
(GAO)

that

the

banned

harmful
Office

not

wary.

U.S.,
(Table

(Eschaege,

Drug Administration's

analytic techniques does not

even check for 70 percent of about 900 food tolerances for
cancer-causing pesticides.
Environmental Impacts of Pesticide Use
Historically,
on the economic

a great deal of emphasis was placed

aspects

of pesticide use.

The

farmers'

primary concern has always been to raise farm productivity
and

yields

other hand,

and

to

make

profits.

The

consumer,

on

the

has always been interested in purchasing the

38

product at an affordable
the

consumer

commodity
(which

always

is

(low)

wants

available

results

in

More

importantly,

the

agricultural

to know that

and

higher

price.

that

there

prices).

farmer-consumer-consumer-farmer

is

The

no

scarcity

outcome

interaction

is

of

this

that

much

attention has been paid to yields, profits, and quality of
the products without much thought to the environmental and
other consequences of pesticide use.

Pesticides have been

used to ensure protection against pests and to enhance the
cosmetics of the products.
In 1962, Rachael Carson (1962) alerted her readers
about

the

Spring.

dangers

of

chemicals

in

the

book

the

Silent

Almost three decades later, the warning generated

in the book is very much as applicable in today's society.
In fact, it seems at times that the warning by Carson has
gone

unnoticed.

U.S.,

Except

1960s,

than

banning

of

DDT

in

the

and

More pesticides are in use today than in
unlike

insecticides,

Between

1964

than tripled

and

crop' acreage

are

1985,

and today,

row crop acreage

1988).

the

there appears to be no other drastic changes since

the early 1960s.
the

for

in

the
the

1960s,

herbicides,

dominant

farmers'

use

pesticides
of

used.

pesticides

more

more than 91 percent of the U.S.

and 44 percent of the U.S.

have

rather

herbicides

applied

small grain

annually

(Batie,

39

Table 2.1.

Pesticides Used in Foreign Countries on Food
Exported to the United States

Commodity

Countries
Surveyed

Bananas

Colombia
Costa Rica
Ecuador
Guatemala
Mexico

45

25

37

Coffee

Brazil
Colombia
Costa Rica
Ecuador
Guatemala
Mexico

94

76

64

Sugar

Brazil
Colombia
Costa Rica
Ecuador
Guatemala
India
Thailand

61

34

33

Tomatoes

Mexico
Spain

53

21

28

Tea

India
Sri Lanka

24

20

11

Cacao

Costa Rica
Ecuador

14

7

7

Tapioca

Thailand

4

4

1

Straw­
berries

Mexico

13

—

5

Peppers

Mexico

12

—

4

Olives

Italy
Spain

20

14

8

201 (59%)

198 (58%)

Totals
Source:

Allowed
Recommended
or Used in
the U.S.

340
Weir and Shapiro (1981).

Any Residues
Prohibited
(no U.S.
Tolerance)

Not De­
tectable
with
FDA Tests

40

The FDA (1978) has shown that more than 15 percent
of the beans
Mexico

and 13 percent of the peppers imported from

were

in

violation

standards at one time.
green

coffee

pesticide

beans

has

(Table
also

FDA

pesticide

residue

Similarly, nearly one-half of the

imported

residues

contamination

of

contained

2.2)

been

(FDA,

traces
1988).

observed

in

of

banned

Pesticide

imported

beef

resulting in the suspension of beef imports, such as from
Mexico (Mitchell, 1979).
Like
more

and

the discovery

more

pesticides

of pesticides
today

are

being

both groundwater and surface water.

in

food

items,

discovered

However,

in

unlike the

tainted grapes and pesticide-laden food items, groundwater
contamination,
unique

in

problem

particular,
and

by

pesticides

concern.

The

raises

uniqueness

a
is

characterized by the fact that the problem is "unseen" or
"invisible."

It

is

a problem which fits

"out of sight, out of m i n d ,"
problem
nitrates

of

groundwater

have

The cliche explains why the

contamination

gone unnoticed

the cliche of

for

so

by
long.

pesticides
In her

Carson (1962) wrote,
The problem of water pollution by pesticides can
be understood only in context as part of the
whole to which it belongs— the pollution of the
total environment of mankind.
The pollution
entering our waterways comes from many sources:
radioactive wastes from reactors, laboratories
and hospitals; fallout from nuclear explosions;

and
book

41

Table

2.2.

Pesticides
1977)

Country of Origin

in

Imported

N o . of Samples

Coffee

Beans

(1974-

No. with Residues

Angola
Brazil
Colombia
Costa Rica
Dominican Republic
Ecuador
El Salvador
Guatemala
Haiti
Honduras
India
Indonesia
Ivory Coast
Kenya
Mexico
New Guinea
Nicaragua
Panama
Peru
Rwanda
Uganda
Venezuela

1
2
21
2
1
10
2
5
1
2
4
1
2
1
5
2
2
1
5
1
1
2

1
2
5
0
0
6
1
2
1
1
4
1
1
0
4
1
0
0
2
1
1
1

Total (22)

74

35

Percentage Contaminated:
48.3%
Pesticides Detected:
DDT, DDE, BHC, Lindane, Dieldrin,
Heptachlor, Diazinon, Malathion
Source:

Weir and Shapiro, 1981.

42

domestic wastes from cities and towns; chemical
wastes from factories.
To these is added a new
kind of fallout— 'the chemical sprays applied to
croplands and gardens, forests, and fields. Many
of the chemical agents in this alarming melange
imitate
and
augment
the harmful
effects
of
radiation, and within the group of chemicals
fHemselves
there
are
sinister
and
littleunderstood
interactions,
transformations,
and
summations of effect.
Cohen

et

al.

(1986)

noted

that

"at

least"

17

pesticides were found in groundwater in 23 states because
of agricultural practices (Table 2.3, Hallberg, 1987).
largest number
New

York,

of pesticides were detected

and

Iowa

because

there

were

The

in California,

more

monitoring

activities in those states.
Aldicarb
groundwater
factors

in

and

Suffolk

attributed

groundwater

other

pesticides

County,

to

the

in Suffolk County

New

were

York.

presence

of

detected
The

in

primary

aldicarb

in

"include the pervasive and

high rates of use of aldicarb, its high water solubility,
heavy

spring

rainfalls

following

application,

very

permeable soils typical of glacial outwash deposits, cold
soil temperature, acid soil conditions, low organic matter
content, shallow water table conditions, and the presence
of many shallow wells immediately down gradient of treated
fields"

(Holden, 1986).
Pionke

atrazine

in

et
14

al.
of

(1988)
the

20

detected
wells

concentrations
tested

of

"suggesting

widespread atrazine contamination of the groundwater at

43

Table 2.3.

Typical
Positive
Results
of
Groundwater Monitoring in the U.S.

Common Name Active
Ingredient

Typical
Concentration
g/1

Pesticide

Number of
States

Herbicides
4
5
1
2

- 700.0
- 5.0
- 0.4
- 4.0
- 3.0

1
1
2
1
3

•

0

1

- 10.0
3.0
300

50.1
1.0
0.1
0.0
0.2

•

o

0.10
0.3

H

Alachlor
Atrazine
Bromacil
Cyanazine
DCPA (and
Acid Product
Dinoseb
Metolachlor
Metribuzin
Simazine
Insecticides and
Nematicides
Aldicarb (sulfoxide
and sulfone)
Carbofuran
DBCP
1,2-DCP
Dyfonate
EDB
Oxamyl
1,2,3-Trichloro£•*4
-

-

50.0
50.0
20.0
50.0

0.05 5.0 -

20.0
65.0

15
3
5
4
1
8
2

5.0

2

0.

on a
W44V

(impurity)
Source:

1.0
1.0
0.2
1.0

Cohen et al., 1987

0.1

-

44

extremely

low

concentrations."

Similarly,

Simazine

was

found in 35% of the wells "at very low concentrations."
Dibromochloropropane
detected

(DBCP),

in more than 2,000

a

nematicide,

was

wells and was known to have

contaminated groundwater in a 7,000 square mile region of
the San Joaquin Valley in California (Holden, 1986).
was

used

in

registration

California

was

from

cancelled

in

the
1977.

1950s

DBCP

until

the

Its manufacturers

announced that the pesticide was found to cause sterility
in male workers involved in its manufacture
Aldicarb,

alachlor,

and

other pesticides

(Ware, 1983).

have

also

been

detected in Wisconsin and Florida (Holden, 1986).
Samples
wells

in

from more

Minnesota

than 700 wells in Iowa and 500

indicated that

between

33

and

38

percent of all the wells tested showed pesticide residues
(Table 2.4)

(Hallberg, 1987).

Hallberg
r— n m m n n

into

(1987)

r>oer+* H r*H Hoc?

groundwater

persisting

in

and

subsoil

inferred

that

many

ocnor

^ a 1 1 \f V>o*-V>
Hoc* ^
^ 4Wr*4
MbWIW

that

several

and/or

of
a v o4
.W

the

most

1X.W««tW44a.44^
.

of the

herbicides

are

groundwater

throughout

the

environmental

problems

year.
On-site
resulted

from

and

off-site

pesticide

fungi, nematodes, weeds,
become

resistant

to

application.

On-site,

have

insects,

and other pets have resurged and
chemical pesticides

and

offsite,

agricultural chemicals have not only disrupted adjacent

45

Table 2.4.

Pesticides Detected in Groundwater Supplies in
Iowa and Minnesota

Common Name
Active Ingredient

Maximum
Concentration
g/1
Iowa/Minnesota

Percent of
Detections
%
iowa/Minnesota

Herbicides
Alachlor
Atrazine
Chloramben
Cyanazine
Dicamba
Metolachlor
Metribuzin
Picloram
Propachlor
Simazine
Trifluralin
2,4-D
2, 3, 4-TP

16.6/ 9.8
21.1/42.4
1.7/N.D.
13.0/ 0.10
2.3/ 2.1
12.2/ 2.1
6.8/ 0.78
N.D./ 0.13
1.7/ 0.52
N.D./ 2.6
0.2/N.D.
0.2/ 4.2
N.D./ 0.26

15/11
72/72
<1/0
12/1
2/2
10/2
0/2
0/1
1/3
0/<l
1/0
<1/2
0/1

N.D./30.6
0.06/N.D.
0.07/ 0.21
0.90/N.D.
0.10/N.D.
12.0 / 0/63

0/<l
2/0
<1/2
1/0
<1/0
2/<l

insecticides
and nematicides)
Aldicarb
Carbofuran
Chlorpyrifos
Fonofos
Phorate
Terbufos
Note:
Source:

N.D. « Not Detected
Hallberg, 1986.

46

and

even

distant

ecosystems

but

have

also

destroyed

sensitive nontarget crops (Hinkle, 1985).
Koeman
deliberate

(1985)

misuse

noted

of

that

the

pesticides,

injudicious

especially

use

in

or

certain

tropical countries, have been largely responsible for some
cases

where

economic

there

species,

have
such

been
as

large-scale

fish

and

mortality

edible

of

crustaceans.

Similarly, damages have been done to pollinating insects.
It was also
water

suggested that the presence of pesticides in

systems

may

depress

that

form an

wildlife

(Koeman,

invertebrates
fish

and

the

populations

of

important source
1985).

In

aquatic

of food

addition

to

for
the

potential damage to economic species, pollinating insects,
and aquatic invertebrates, it has also been suggested that
pesticides

may

have

plant communities
al.

1985)

fauna

fauna

pests

and

was

effects

in the soil

found that

decreased

Soil

profound

the total

temporarily
noted

(Koeman,

as

having

the processing of litter,

the

animal

1985).

and

Snider et

population of springtail

after

as being important

on

paraquat
economic

in other

was

applied.

importance

areas,

as

such as in

increase in soil porespace and

as food sources for other organisms (Snider et al., 1985).
Grant and Payne (1982) determined the effects some
herbicides

and

denitrification
showed

that

insecticides
in

one

salt
of

marsh

the

on

the

process

environments.

insecticides,

The

dalapon

of
study
at

a

47

concentration

of

lOug/ml

clearly

inhibited

denitrification.
Several

field

studies

reveal

the

presence

pesticides in subsurface and surface environments.

of

Traces

of atrazine ranging from 0.2 to 0.8 ppb was found in the
corn-producing areas of Nebraska and leaching from the use
of atrazine was determined as the cause

(Wehtje,

et al.,

1981).
Harris

(1967)

determined

in a soil column system

that the aromatic acid herbicides were most mobile while
the insoluble toluidines were least mobile.
Wu et al.

(1983) detected atrazine more frequently

and in greater concentration than alachlor and also found
that

runoff

contaminated

waters
with

from

herbicides

forest
in

watersheds

areas

where

were

herbicides

were not directly applied.
Hall (1974) found greater residues of atrazine and
GS13529

in

soil

sediment

analysis

revealed

applied

atrazine

an

than

average

was

in
of

runoff
35.3

recovered

one

water.

percent

The
of

month

the
after

application.
Nash (1968) determined the synergistic impact of a
herbicide

and

an

insecticide.

it

was

found

that

the

combinations of diuron with disulfoton or phorate in the
soil

resulted

in

synergistic

phototoxicities

persisted in the soil for several weeks.

which

48

Volatilization of pesticides from target areas of
soil

and

Helling

foliar

(1987)

received

noted

less

pesticide

surfaces
that

research

fate

in

present

a

unique

volatilization

attention than

conservation

seems

to

have

other aspects

tillage

because of the more complicated

problem.

systems

of

partly

field sampling equipment

needed and partly because of some difficulty in accurately
estimating

total

appreciable

pesticide

amount

of

loss.

Nonetheless,

pesticides

is

lost

an

through

volatilization.
Taylor
pesticide

(1978)

that

indicated that

volatilizes

is

the amount

usually

larger

of

than

the

pesticide that is lost through leaching or runoff and that
volatilization,
degradation
Similarly,
aerial
to

for

pesticides,

is

second

only

in causing dissipation from a treated
Shoemaker

application

nontarget

hundred

most

times

and

Harris

(1979)

of pesticides, the

areas

by

as

large

air

may

as

the

be

noted

amount

field.

that

with

transported

as much as

amount

to

several

transported

by

runoff.
An
pesticide

important
misuse

implications,

is the

aspect
and

of

overuse

resistance

Sommers (1986) noted that:

pesticide,

of

with
pests

particularly
environmental

to

pesticides.

49

since
the early
1900s,
about
450
different
insects have been resistant to one or more
insecticides.
Of these, 60 percent are important
in agriculture.
Adding
to this concern, the
number of resistant bugs has about doubled from
1970 to 1980 and the number of species adapting
to some chemical group has increased 17 times.
During the same period, more than 150 herbicideresistant weeds, at least 100 species of plant
disease pathogens and two species of nematodes
have been identified as resistant to one or more
pesticides.
Resistance
recorded

mostly

of

in

pests

the

U.S.,

to

herbicides

Canada,

have

southern

been

parts

of

western Europe, Japan, Hungary, and Egypt (LeBaron, 1982).
The countries affected are characterized by high levels of
herbicide use,
frequently,

often the same

and

or similar herbicides used

monocultures

or limited

crop rotations

(LeBaron, 1982).
Pesticide

use

and

real health concerns.
interaction
chemicals
largely

between
in

misuse

potential

and

The effects of pesticides, plus the
pesticides

groundwater

unknown.

present

and

Hallberg

and
the

(1987)

other

agricultural

environment
acknowledged

is

still

that

the

unknown effects of the interaction between pesticides and
other

agricultural

issue

of

long-term,

chemicals

uncertainties
chronic

which

health

in

groundwater

exist

effects,

about
such

raises

the
as

the

potential

cancer

and

immune system disorders.
Studies
1979;

in

Iowa

Burmeister et al.,

and
1983)

Nebraska

(Blair

&

Thomas,

have shown that mortality

50

from

some

cancers

families.

is

Excessive

myeloma,

and

significantly higher

mortality

non-Hodgkin's

from

in

rural

Leukemia,

lymphoma

has

multiple

shown

some

consistent associations with herbicide use.
The herbicide, 2, 4-D has been linked to cancer in
a study in Kansas

(Hoar et al.,

1986).

The study showed

that "farmers exposed to 2, 4-D for more than
yeat

are six

lymphoma

times more likely

(NHL),

a

tumor

20 days a

to develop non-Hodgkin's

of

the

lymph

system,

than

nonexposed farmers."
Preliminary

research

people

showed

farmers

1950's

and

certain

that

1960's may

kinds

of

run

involving
who

used

a greater

cancer,

more

than

pesticides
risk

particularly

2,000
in

the

of developing
leukemia

and

lymphoma (Allen et al., 1986).
Tevis

(1988) noted studies in Nebraska and Kansas

which appeared to link 2, 4-D and non-Hodgkin's lymphoma.
Leukemia

was

found

to

be

35

percent

farmers,

while lymphoma was 29 percent

more prevalent

in

more among farmers

than the general population.
There
particularly

are
the

pesticide-related
the

decline

fatalities

other

misuse

of

accidents

in

the

have

been

U.S.

pesticide-related
pesticides.
and

attributed

The

fatalities

(Table
to

problems,

2.5).
careless

number

have

been

Most

of

handling

of
on
the
or

51

storage practices and many of the fatalities have involved
accidental ingestion by children (Keith, 1987).
Barrons
illnesses
number

of

from

(1987)

observed

overexposure

deaths,

to

although

statistics on illnesses.

that

the

number

pesticides
there

are

exceeds
no

of
the

national

It was noted that illnesses and

fatalities related to pesticide use are decreasing in the
U.S. for reasons which include (Barrons, 1987):
1.

the

elimination

of

certain

products

and

practices that were hazardous,
2.

the strengthening of precautionary statements
on pesticide labels,

3.

new rules specifying when it is safe for farm
workers

to

reenter a treated

field,

orchard,

or vineyard,
4.

the grouping of pesticides into restricted and
nonrestricted
available

categories,

only

to

with

licensed

the

former

farmers

and

operators, and
5.

improved understanding by farm managers of the
need

for caution

parallel

improved

and worker education,
awareness

on

the

and a

part

of

home and commercial applications.
Although
related

to

the number of

pesticide use

is

illnesses

and

fatalities

declining, farms

still have

the dubious recognition as the deadliest workplace in

52

Table 2.5.

Number of Lethal Pesticide-Related Accidents
in the U.S. in Different Years

Time Period

Lethal Pesticide-Related
Accidents Per Year

1956

152

1961

111

1968-1970

55

1971-1973

38

1974-1976

32

1977-1979

31

1980-1982

28

1983-1984

27

Source:

Keith C. Barrons, "How Risky are Pesticides."
Science of Food and Agriculture Journal 5(1)
(1987): 22.

53

America.

Wilkerson

(1988)

wrote

that

farming

has

surpassed mining and construction in recent years as the
nation's deadliest occupation and is claiming the lives of
hundreds of children and leaving thousands disabled.
was

noted

through
host

that

about

tractor,

of

other

1,600

rollovers,

adults

were

killed

in

farm

machinery

gears,

In

addition,

160,000

accidents.

It
1987

and

a

were

disabled, and it has been observed that 300 children under
the

age of

16 died

in farm-related mishaps while

23,000

children were injured using or playing near farm equipment
(Wilkerson, 1988).
In 1987, "the

farm death rate was

100.000

workers as

mining,

35 per 100,000

in

against

manufacturing."

deaths per
100.000

per 100,000 in

in construction and 6 per 100,000

Compared

workers in mining

the

deaths

per

to

1978,"there

were

52

100,000 farm workers as against 56 deaths per

construction"
of

38

49deaths

and

48 deaths

(Wilkerson, 1988).

farm

deaths,

per 100,000 in

It is not clear how many

accidents

and

illnesses,

is

attributable directly to pesticides and pesticide use.
Besides

human

injuries,

illnesses,

and

deaths

resulting from pesticide use and misuse, pesticide injury
on crops
such

is

also a concern.

injuries

farmers.
seed yield

on

crops

Stoller et al.
suspected

Minimizing and

improve

yields

(197 3) observed

to be due to

and

eradicating
profits

a reduction

for
in

injury from excessive

54

herbicide
There

rates

is

or

also

competition

the

from uncontrolled

concern

of

possible

alterations induced in food by pesticides
Penner

and

Meggitt

composition,
treatment

(1970)

yield,

and

involving

13

found
plant

nutritional

(Stoller, 1973).

changes
injury

herbicides

weeds.

in

fatty

resulting
in

two

acid
from

soybean

cultivars.
Factors that Determine the Movement
of Pesticides in the Environment
„How

effective

applied

pesticides

and

especially are depends on several factors
transport or movement of herbicides.
of

herbicides

leaching

is

surface

dependent

Consequently,
negative

through

it

is

presumed

impacts

of

pesticide

a

related to the

Similarly, the loss

runoff,

on

vaporization

number

that

herbicides

of

factors.

the magnitude

use

and

and

misuse,

of

the

such

as

ground and surface water pollution is intricately tied to
the factors that influence the movement of herbicides.
Bailey

et

al.

(1974)

noted

that,

of

the

many

factors that influence the extent of pesticide runoff from
agricultural land,
pollution.

several may be controlled to minimize

Furthermore,

Bailey

et

al.

(1974)

concluded

that if the effects and interrelations of pesticide type
and

formulation,

soil

properties,

climatic

conditions,

watershed characteristics, and agricultural practices were

55

clearly

known,

usage

guidelines

could

be developed

that

would aid in preventing runoff and subsequent pollution.
Hartwig and Hall

(1980) indicated that the amount

of herbicide loss depends on soil, climatic, and herbicide
factors.

The soil factors include texture, porosity, pH,

organic

matter,

soil

water

content,

and

slope.

The

climatic factors are proximity of the rainfall in relation
to

herbicide

application

and

to

intensity,

and duration

of

amounts.

included

herbicide

in

other

rainfall,

and

rainfalls,

total

factors

is

rainfall
herbicide

formulation and whether the herbicide is applied directly
to

plant

foliage,

the

soil

surface,

or

is

incorporated

into the soil (Hartwig and Hall, 1980).
Glotfelty
amount

of

et

herbicide

al.

(1984)

reaching

showed
the

that

Wye

the

River

total

estuary

dependend upon the quantity applied and the timing of the
runoff with
that

the

respect to application dates.

most

important

rainfall

events

occur within two weeks of application.
formulation of the herbicide,
confirmed

to

be

critical

It was
are

found

those

that

In addition,

the

especially wettable powders

since

they

are

susceptible

runoff losses.
Willis and Hamilton (197 3) wrote that
the magnitude of pesticide loss in runoff depends
on a number of variables including the chemical
properties of the compounds, rate of application,
topography, vegetative cover, runoff volume, and
climatic factors such as rainfall Intensity.

to

56

Triplett

et

al.

(1978)

found

that

the

quantity

of

herbicides transported increased with the amount of runoff
and was

inversely

related

to the length of time

between

application and runoff event.
Utilizing
holistic since
permit

the

system

an

"an isolated

comprehensive

because

interactively,',!
response

of

chemical

agro-ecosystem

separate
et

al.

agro-watershed

pollutants is

physico-chemical

billed

as

study of the parts will not

understanding

the
Bailey

an

approach

of

the

complete

are

linked

parts

(1985)
to

stated

that

pesticides

or

the
other

"determined by the combination of

characteristics

of

the

soils

and

chemicals themselves, topography, vegetation, geology, and
well and drainage networks."

Inputs into the systems were

categorized as deterministic and stochastic with examples
as

timing

of

pesticide

occurrence of rainfall
from

the

sediment,

application

(stochastic).

agro-ecosystem,
pesticides,

oxidized organics,

(deterministic)

Outputs originating

"include

nutrients,

and

food

and

heavy metals

fiber
and

plus

easily

plus residues on the land surface,

in

runoff and leachate and in the air" (Bailey et al., 1985).
As
Figure

illustrated

2.2,

multimedia

"the
in

by

Bailey

watershed

dimension

et

level

(land

to

atmosphere, and atmosphere to land)."

al.

(1985)

response
water,

and

in

can

be

land

to

57

UANACEUENT INPUT
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NATURAL INPUT

AIRSHED OUTPUT

hlfttlUiplTM

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■»««r

PtlUCllilM

WATERFLOW

N aar^U «U J^
iHlMt
ftuaell

M to n t U m M
C h iu c i li

Figure 2.2

Source:

OlMalvad I
C k ta ic ilil

OUTPUT
ir

Datmua Ito iM
CkoMcola

JllkNIIUI
no*

Dl*«ol**d
OiiiiiMli

Crouad
■•tor

Factors Influencing the Behavior and Export
of Agricultural Chemicals From an
Agricultural Watershed.

Bailey, Mulkey, and Swank. Environmental
Implications of Conservation Tillage: A
Systems Approach, 1985.

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tC C E N D
O U R lR G

B C fW F C N

v O IS S O L U T IO N /
S'X
v --------------------/
/ L IQ U I0 * L l O m O x

P R IO R

f

Source:

TO

(V (N T

R A IN F A i l
F IR S T

EVENT

R A IN F A L L

C vC N f

PROCESS

D IF F U S IO N
\IN T £ llC H A N G E ^ /

Figure 2.3

R A IN F A L L

/ s t a t io n a r y ,

O

FACTOR

Processes and Factors which Determine the Concentration of
Pesticide Available for Runoff from Agricultural Land.
Climatic Factors lying Outside of the Dashed Lines are
Exogenous with Respect to the Soil-Pesticide System.
Bai?ley, et al., 1974.

59

Bailey

et

characteristics
from

the

al.

of

They

basic,

pressure,

also

pesticides

soil.

anionic,

(1985)

or

partition

noted

that

include

acidic),

chemical

influence

ionic
water

coefficient,

some

state

transport
(cationic,

solubility,

vapor

hydrophobic/hydrophilic

character and chemical and biological reactivity.
Factors
pesticides
further
al.

are

determining the movement or transport

of

complex

complexity

is

by Bailey

et

leaching

or

illustrated

in

nature.

in Figures

This

2.2

and

2.3

(1974).
Pesticides

downward

movement

acknowledged
result

also

into the

that

of water

are

lost
soil.

"pesticides
infiltration

soil during conditions

through
Bailey

move
and

into

et

the

flow."

(1985)

soil

vertically

of saturated

al.

as

through

a

the

Furthermore,

it was acknowledged that "downward movement starts before
runoff

since

intensity

runoff

exceeds

the

does

not

begin

infiltration

rate

until
or

rainfall
the

water

volume exceeds the total storage capacity of the system."
Important

factors

seen

to

influence

leaching

include,
adsorption-desorption,
chemical
reactions,
pesticide application rate, water solubility of
the pesticide, and physical properties of the
soil, particularly those that determine average
pore water velocity, water flux (flow rate), and
total amount of water (Bailey et al., 1985).

60

Of

all

the

factors,

adsorption

was

noted

as

the

most

important factor of all.

A further discussion of the key

physical

characteristics

and

leachers

and

transport

chemical
the

to

key

soil

groundwater

factors

is

of

pesticide

affecting

included

in

pesticide

the

appendix.

Also included in the appendix are herbicide formulations,
choice of formulations,

and herbicide classification

and

mode of action.
No-Till (NT) Compared to
Conventional Tillage (CT)
Definitions
No-till planting, also known as zero-tillage, is a
form

of

conservation

tillage

undisturbed until planting.

in which the

soil

is

left

Equipment merely opens slots

in the soil

to place seeds or fertilizer during planting

operations

(Conservation

Tillage

Information

Center,

1985).
Conservation
tillage

sequence

relative
inversion
residue
Glossary,
when

to

tillage

that

reduces

conventional

tillage
mulch
1982).

30 percent

on

that
the

has

been
loss

tillage;
retains
surface"

defined
of

often

soil
a

protective
(Resource

form

as
or

"any
water

of

amounts

non­
of

Conservation

The term "conservation tillage" is used
of the soil surface

is covered

residues from previous crops after planting
Tillage Information Center, 1985).

by plant

(Conservation

61

van

Es

as

a

farming

accomplished
involving

known

farming

of

by

the

use

the

on

at

weed
of

soil
least

year.

tillage

characterized

where

the

of

residues

clean

(1988)

method

entirely

throughout
as

Notier

noninversion

maintenance
surface

and

control

well

defined

as

and

as

percent

Conventional

was

is

herbicides

as
60

no-till

the

of

tillage

the
also

involving

the

inversion of the filled layer and incorporating residue to
prepare a clean seedbed.
Christensen

and

Magleby

(1983)

described

conventional tillage as where 100 percent of the topsoil
is

mixed

and

inverted

by

plowing,

power

tiller,

or

multiple diskings.
History and Trends in No-Till
Three events are
of no-till.

involved

Van Es and Notier (1988) noted that the first

application of no-till

farming was

resulting

from

tests

Jersey

1945

and

have

originated

known

in
to

in the initial history

conducted

1949,

Wisconsin in the 1920's.

in

in pasture renovation
Connecticut

respectively.
out

of

a

The

research

and

tests

New
were

begun

From the 1949 research,

in

it was

discovered that "chemicals, even without discing, achieved
good results for forages."
In terms of effectiveness,

it was noted that the

first effective demonstrations of the possibility of using

62

no-till for row crops were conducted in the early 1950's
in Michigan by Barrons

(Van Es and Notier, 1988).

The third event with regard to the history of no­
till

is

in

terms

of

farm

experiences.

The

best

known

experience dates back to 1950's by a group of farmers in
Christian County, Kentucky (Van Es and Notier, 1988).
farmers were

said to have begun no-till

The

in an emergency

when a wet spring made cultivation impossible and causing
weeds

to

be

chemically

controlled.

King

(1983)

also

reported that no-till began in Kentucky.
Trends
No-till

was

in

its

preliminary

stages

in

the

1960s, but has grown remarkable since in terms of acreages
in

the

U.S.

No-till

acreage

in

1982

was

10.5

million

acres compared to 3.3 million acres (or an increase of 313
percent)

in

1972.

In

1981,

no-till

acreages

increased

22.1 percent from 1980 and from 1981 to 1982, there was an
additional

13.4

percent

increase

(No-till

Farmer,

Inc.,

1982).
The
percent

1988

increase

Michigan
in

No-Till

no-till

1987 to 282,000 acres in 1988.

corn

Survey
from

showed

250,000

a

13

acres

in

No-till soybeans showed an

even larger growth as acres of no-till soybeans increased
40 percent from 49,000 acres to 69,000 acres from 1987 to
1988.

63

Factors Attributed to the Rise In
Interest In No-TllI
Phillips
contributed

to

(1984)
the

noted

increased

four

interest

factors
in

which

no-till.

The

factors are:
1.

the

development

of

plant

growth

regulators,

especially the nonselective contact weed control material
which

provided

the

ability

to

eliminate

or

severely

suppress existing vegetation,
2.

population

shifts

to

urban

areas

which

depleted farm labor and resulted in capital investment in
substitutes,

such

as

pesticides,

equipment,

and

other

production items,
3.

the

manufacturers
capable

of

introduction

of

modified

placing

seeds

by

no-tillage
into

farm

equipment

planting

equipment

uncultivated,

unprepared

soils, and
4.

the

fact that

associated

reduced

receptive

to

yields

practices

"farmers

faced with normal and

by delayed
that

planting

would

save

were more
time

in

establishing crops such as was afforded by the adoption of
no-tillage."
Characteristics of No-Till Farmers
Bultena and Holberg (1983) remarked in their study
in

Iowa

determining

conservation tillage,

factors

affecting

that early

adopters

adoption

of

of innovations

64

such as no-till often differ in their characteristics and
other situations from person who adopt practices later or
persons

who

never

adopt

Bultena

and Holberg

new

(1983)

practices.

found

that early

conservations tillage were younger,
had

higher

taking,

farm

had

cropland"

incomes,

more

Furthermore,
adopters

"farmed larger units,

were more predisposed

potential

for

of

soil

erosion

to riskon

their

as well as the perception that "others in their

local communities generally favored conservation tillage."
Carlson
study

of

Pacific

early

and

adopters

Northwest

especially
education

that

rented
and

Dillman
and

more

also

nonusers

"no-till

land;

were

(1986)

had

users

higher

likely

to

noted

in

of no-till

their
in

farmed more
incomes,

farm

under

land,

had
a

the

more
family

corporation."
Explaining
adopters

and

some

nonadopters

of
of

the

differences

innovations,

between

Bultena

and

Holberg noted that younger and better-educated people, for
example,

"usually

practices,
more

are more knowledgeable about the newer

are

more

incentive

for

period."

receptive
adoption

to

risk-taking,

because

of

and

longer

have

payoff

65

Advantages of No-Till
Moody et al.

(1961)

found that it is possible to

grow corn in "a dead sod with no tillage."

Furthermore,

Moody (1961) indicated that:
this
new
approach
to
growing
corn
affords
excellent soil and water conservation in that the
dead grass acts as a mulch to protect the soil
surface, thereby reducing runoff and evaporation.
In addition, the data suggests that tillage may
have destroyed the favorable structure that grass
crops usually promote.
Several

studies

including King
(1983),

Baker

(1985),

and

Van

Es

et

al.

and Fenster

Moldenhauer

(1985), Blevins et al.
(1985),

Moody

(1983), Mannering

Moldenhauer

Thomas

since

et

(1961),

(1983),
al.

(1983),

(1983), Rotz et al.

(1988)

and

Stinner

Lee

(1985),

and

House

(1989) have discussed the advantages of no-till as well as
the concerns or disadvantages.
no-till

include

erosion

Some of the advantages of

control

energy, and machinery costs.

and

savings

in

time,

Glenn and Angle (1987) found

that there was less runoff of water, atrazine and simazine
from NT compared to CT.
Burnside
tillage

cropping

(1985)
systems

listed
which

some

advantages

includes

of

no-till.

are:
1.

Reduced soil erosion

2.

Moisture conservation

3.

Reduced energy and labor needs

4.

Reduced equipment and production costs

lowThey

66

5.

Fewer destruction of fauna and

6.

Increases in soil organic matter

Phillips

(1984)

noted

that no-tillage

techniques

offer another advantage in that they are adaptable to most
crops.
Acknowledging potential

"sweeping generalizations

with many exceptions to every rule," Gersmehl (1978) wrote
that "no-till farming interposes a barrier of dead organic
material

between

Consequently,
or

the

the

soil

and

the

atmosphere."

"raindrop impact is absorbed by the dead sod

residues

of

previous

crops.

Wind

is

likewise

blunted and unable to dislodge soil particles."
Gersmehl (1978) also wrote that
no-till farming alters the water budget of the
soil surface.
The structure of the soil is
improved, with less tendency to from a crust.
Water can infiltrate more rapidly and the soil
becomes more moist. Root growth is enhanced,
except on already wet sites.
The increase in
infiltration leads to a reduction in overland
runoff, accompanied by declines in soil erosion,
fertilizer loss, and the rate of sedimentation
and eutrophication downstream;
Furthermore, Gersmehl (1978) indicated that in no­
till farming,
"less labor

fewer trips are required across a field and

is needed

can be more timely.

for fieldwork,

so field operations

Less fuel is used, less horsepower is

needed, and less capital is tied up in machinery."
The

advantages

of no-till not withstanding there

are problems and concerns

associated with it.

Glenn and

67

Angle

(1987)

aquatic

suggested

vegetation

tributaries may

that

(SAV)

in

the
the

be attributed

and herbicide use.
ecological impact,

decline

in

Chesapeake

to

an

submerged

Bay

increase

and

in no-till

A primary concern of no-till
especially,

its

is the

on the groundwater as well

as potential and unknown effects of direct human exposure
and

contact.

The

concern

exists

about

groundwater

contamination because infiltration increases with reduced
tillage (Brink, 1977).
Several studies, including Phillips et al.
Crosson
(1982)
used

(1981), Crosson et al.

indicated that more pesticides
in

conservation

conventional
since
the

tillage.

pesticide use

energy

tillage

is

inputs

when

budget."
more

corn

tillage

seeds
till

"sometimes

doubled

input often excluded
such energy

al.

be

costs

greater

are

offset

13%)
poor

noted
in

consequently

in
that

with no-till,
conventional

in

the

that

energy

the use

no-till

germination

in the energy budget.

are

than

suggested

than

included

(1980)

(about
to

no-till

(1984)

would

et

and

(1985) Hayes

and herbicides

Pimenthal

pesticides

Phillips

conventional

of

(1986), Baker

(1980),

than
is

of
in

energy

The addition

would make

for higher

energy inputs in no-till than in conventional till.
Other concerns were indicated by Phillips
They include:

(1984).

68

1.

a higher level of management or new technology

that would be required by growers,
2.

fertilizer

usage

and

timing

which

may

vary

from that of conventional tillage,
3.

producers

who must

learn planting techniques

that will provide sound planting principles, and
4.

the aesthetics associated with no-till as many

farmers find it difficult to accept the ragged appearance
of no-till compared to the clean soil surface associated
with conventional till.
Gersmehl
time

decreases,

increases"and
offset
equal

(1978)

by

in

acknowledged
no-till,

that

"management

reductions in machinery

higher

to those

pesticide

although labor

and

expenses.

from conventionally

complexity

fuel costs

Yields

plowed

are

fields

are

often
and

in

some case are significantly higher, but the potential for
spectacular

crop

failure

is

also

greater,

because

a

reduction in the number of field operations also restricts
the opportunity to correct errors.
Wauchope
especially
whether
Estimated

for

(1987)

answered

herbicides

conservation
increases

in

a

categorically
self-posed

tillage' increases
for

herbicide

range from 15 to 60 percent.

use

question

pesticide
was

"yes,"
on

use.

observed

to

69

Theory of Self-Interest
Farmers

have been known historically to maximize

profits by maximizing yields.
lands

were

put

fertilizers

and

(Brink,

into

general.

It

production

pesticides

1977).

This

characteristics

In recent decades, marginal

of

with

to

extra

achieve

behavior,

farmers, is

maximum

which
common

inputs

is

yield

not

to

of

only

people

in

is associated with an influential theory of

soclety-nature

relationships

in which

people

respond

to

their physical environment, and thus, also to each other,
on

the

basis

of their

and

Stabler,

(Rickson

short-term
1985;

economic

self-interest

Gordon, 1954;

and

Hardin,

1968).
Rickson
assumption
resource
returns

and

is that,
will

from

inevitable
gradual,

Stabler (1985)

"individuals using

attempt
using

it,

destruction
if

resources,

indicted

unintended,

to

the

maximize their

and

to

with

share

the

others.

The

degradation

of

that

the

same natural
benefits
costs

of

result

commonly

is

or
its
a

owned

such as land, air, or water, and a 'tragedy of

the commons.'"
In
the

summary,

literature

herbicides
pesticides,

Chapter

including

and

II covered

the

historical

pesticides, trends

economic

several

importance

in
of

items

in

development

of

the

use

of

pesticides,

environmental and health implications of pesticide use and

70

misuse,

herbicide formulation,

comparison between no-till

and conventional till and the advantages and disadvantages
of no-till.

CHAPTER III
DESIGN OF THE STUDY

This

chapter

population,
instrument
followed

the

includes

selection

utilized

in

a

of

data

in collecting the

description
the

the

population,

collection,

data,

of

the

the
steps

and the limitations

of

the study.
The Population and Its Selection
The

population

for

this

study

was

comprised

of

376 no-till corn farmers in nine counties in the southern
peninsula of Michigan.
Clinton,

Eaton,

Lenawee

(Figure

The counties are Berrien,

Hillsdale,
1.2).

Ionia,

The

Ingham,

population

Cass,

Isabella,

was

provided

and
by

District Conservationists in the nine counties with each
providing a list of no-till corn growers from each of the
counties.
of

no-till

Each of the counties had 10,000 or more acres
corn,

Michigan in 1986.
the

most

widely

Consequently,
to

be

applied

the

largest

no-till

corn

acreages

in

No-till corn was chosen because it is
grown

grain

crop

in

Michigan.

a greater amount of herbicides was expected
to no-till

corn than

71

to

any

other

grain

72

crop such as wheat or soybean.
more
are

Fleming (1987) noted that

than half of the herbicides applied to field crops
applied

half

of

to

all

corn

the

and

that

corn

fertilizer used

accounts

in the

for

U.S.

almost

Corn was

also chosen because it is a popular crop universally.
The list of the
District

farmers were solicited

Conservationists

through

phone

from the

calls,

letters,

and personal contacts by the researcher.
Instrumentation
A

survey

questionnaire

was

developed

to

gather

information that responds to the research questions
Appendix A) .
1989,

two

there

Since

similar

was

one

questionnaire
of no-till

surveys

questionnaires
additional

added to

corn

were conducted

question

retrieve

acreages

were

(see

in 1988

used,
in

although
the

1989

information on the

planted

in

1987

and

size

(see Appendix

B).
The
assistance

survey/questionnaire
of

particularly Dr.

the

was

researchers

J. Kells

and Dr.

developed
committee

E. Dersch,

with

the

members,
as well

as

Dr. Frank Fear, Chairperson of the Department of Resource
Development,

and

Dwight

Conservation Agronomist
Service.
wide

A mail

geographical

Quisenberry,

formerly

with the U.S.

Soil

questionnaire was used
distribution

of

the

the

State

Conservation

because

of the

population

and

73

because it was comparatively more time and cost efficient
than telephone or face-to-face surveys.
Mr.

Quisenberry

Conservationists

were

and

involved

two
in

other

a pilot

District

study.

They

critiqued the questionnaire from the viewpoint of farmers
since they have had many years of experience working with
farmers.

Another expert with the U.S. Soil Conservation

Service who is also a farmer was asked for his

feedback

on the survey.
The questionnaire was divided into four sections.
The

sections

well

as

asked

questions

institutional,

relating

environmental,

to

practice,

and

as

demographic

questions.
Administration and Return
of Questionnaires"
A cover letter was attached to the questionnaires
before they were mailed.
by

the

researcher

and

Dwiyht

Conservation Agronomist.
was

to

assure

the

The cover letters were signed

Mr.

Quisenberry,

former

State

D. Quisenberry's signature

District

Conservationists

and

the

farmers of the intent and the need for the study, as well
as to add credibility to the study.
This

study

involved

survey questionnaires.

two

batches

of

the

same

On April 20, 1988, questionnaires

were mailed to 200 randomly selected no-till corn farmers
in

the

nine

counties

under

study.

Thirty-nine,

or

19

74

percent,

responded

prior

to

was sent on May 23, 1988.

the

follow-up

letter

which

After the follow up letter,

a

total of 81 responded.
Although 81 farmers responded, only 53 were valid
since

28

farmers

farmers.

Two

indicated

surveys

that

were

they

were

returned

not

because

no-till

they

were

undelivered due to change of address.
In
study,
to

an effort

to

improve on

the validity

of the

another set of the same questionnaires was mailed

the

rest

of

the

farmers

(176).

were mailed on February 14, 1989.
mailed

to

each

March 14,

1989.

of

the

farmers

The

questionnaires

A follow-up letter was
in

the

second

batch

on

The questionnaires were sent this time

in winter prior to the farming season with the hope that
a higher number of responses would be received since the
farmers were not expected to be as busy as in the early
farming

season

terminated

on

in

Spring

April

14,

(April-May).
1989,

a

week

The

survey

after

no

was

other

response was received.
Forty-four invalid responses were received out of
a total of 83 responses.

The invalid responses consisted

of eight returned envelopes due to change of address,
responses

that

responses

which

data,

do

were

particularly

applied.

not

plant
not

acreage

no-till

utilized
of

corn,

because

no-till

and

and
of

28

eight

missing

herbicides

75

The

valid

added to the
30.2%

of

responses

1989 valid

the

from

responses

population

the

1988

survey

for a total of

excluding

the

were
92 or

returned,

but

invalid, responses (Table 3.1).

Table 3.1.

Number of Mailed Questionnaires and Response
Rates

First Mailing
(4-20-88)

Total Number Sent

Second Mailing
(2-14-89)

200

176

Total Number of
Responses

81

83

Total Number of
Valid Responses

53

39

Total of Invalid
Responses

28

44

Total of Valid
Responses

92

Total Percentage = 30.2%

Data Analysis
Statistical
(SPSSX) was
Simple

used

descriptive

Package
to

statistics

percentages,

to means,

The

analysis

t-test,

analyze

for

the

Social

the

data

for

ranging

from

Sciences

this

study.

frequencies,

and standard deviation were used.
of

variance

(ANOVA)

and

Pearson's

76

Moment Correlation coefficient were utilized in analyzing
some of the research questions.
The primary purpose of the study is to determine
whether

no-till

corn

farmers

in

nine

Michigan

counties

are applying herbicides according to recommended rates on
container labels.
The

primary

dependent

variable

in

the

study

herbicide rates expressed in active ingredients.
advantage

of

ingredient

is

converting
that

the

the

A major

formulation's

result

of

the

active

conversion

expressed in pounds per active ingredient.

is

is

Conversion to

active ingredients was based on the amount of herbicides
as

well

as

formulation.
were

the

concentration

and

the

commercial

For example, atrazine and cynazine (bladex)

applied

formulations

in

various

primarily

quantities,

80%

water dispersible granule

wettable

but

powder

in

three

(80W),

(WDG) or dry flowable

90%

(DF) and

as 4 lb/gal water dispersible liquid suspension (4L).
Three
conversion
atrazine

examples

of

applied

which

was

will

for the

applied

2.5

applied

quarts

of

of

atrazine,

as

to

80W,

to

illustrate

active

wettable

(90 WDG)

illustration.
pounds

used

herbicides

water dispersible granule
used

be

the

ingredients,

powder

and as liquid

(80W),
(4L)

is

Assuming that three farmers
2.0

lbs

respectively,

active ingredients is as follows:

of
the

90

WDG,

and

1.5

conversion

to

77

1.

2.5 x 0.8 lb a.i. ■ 2.016 a.i.

2.

2.0 x 0.9 lb a.i. = 1.816 a.i.

3.

1.5/4.0 gal 4L=0.37 x 4 lb a.i.=1.48 lb a.i.

The
research

following

questions

is

a presentation

and

a

brief

of

each

description

of

the

of

the

statistical analysis used to address each question.
Research Question

1.

To what

extent

do

herbicides

applied by no-till corn farmers (on their no-till
corn

acreage)

in nine Michigan Counties

conform

with the recommended rates on container labels?
Respondents
herbicides,
quarts,

their

were

asked

to

formulations

kilograms,

or

indicate

and

liters)

the

type

rates

(in

they

applied

of

pounds,
in

preemergence and post-emergence no-till corn.
Based
including

on

the

means,

percentages

were

responses,

standard
used

to

descriptive

deviation,

determine

if

statistics

ranges,
the

and

respondents

applied herbicides according to recommended rates.
Research

Question

2.

To

what

extent

do

herbicide

rates applied by the same no-till corn farmers on
their no-till corn acreage conform with herbicide
rates

they

apply

on

conventional-till

corn

acreage?
Like

Research

Question

1,

asked to indicate the herbicides,

the

respondents

were

formulations, and rates

78

they applied in preplant, preemergence, and postemergence
conventional corn acreages.
Based
deviation,
acreages
ranges,

on

the

ranges,

was
and

responses,

means,

standard

and percentages based on conventional

compared

to the means,

percentages

Furthermore,

the

standard

based on no-till

corn

deviation,
acreages.

the t-test was used to determine whether or

not there exists significant differences in the rates of
herbicides

applied

by

the

farmers

in

no-till

and

conventional till acreages.
Research Question
of

3.

education

To what extent does the level

influence

the

rate

of

herbicides

applied by the farmers?
The
highest

respondents

level

were

of education

asked

ranging

to

indicate

their

from "less than high

school" to undergraduate and graduate degrees.
The

t-test

significance
applied

of

and

education.
education
whereas

the

between

education

those

this

less
with

then

used

to

in

rates

difference

those

less,
In

and

was

respondents

and

those

study,

with
those

are designated
above

high

determine
of

with

the

herbicides

high

school

above

high

school

with

high

school

as the less-educated,
school

designated as the more educated respondents.

education

are

79

Research Question
or

rental

4.

of

To what extent does ownership

farmland

influence

the

rate

of

herbicides applied by the farmers?
The
they

own

respondents

or

rent

were

their

asked

to

indicate

no-till corn acres

"both” apply given the choices of (l) own,

or

whether

whether

(2) rent,

and

(3) both.
Based on their

responses,

the ANOVA was used to

determine whether or not significant differences exist in
the

rates

of

herbicides

applied

either own or rent their

by those

farmers

no-till corn farm and those

who
who

both own and rent.
Research

Question

status

5;

(full-time

To

what

extent

or

part-time)

does

farming

influence

the

rate of herbicides applied in no-till corn?
The respondents were asked whether they are fullor part-time farmers.

The t-test was used to determine

whether or not significant differences exist in the rate
of

herbicides

applied

between

full-time

and

part-time

farmers.
Research

Question

environmental

6:

To

awareness

what

extent

influence

do
the

farmers'
rate

of

herbicides they applied?
Respondents were asked whether or not they think
agricultural

practice

is

a

significant

source

of

80

environmental pollution in their county relative to other
sources of pollution such as industries.
Based
determine

on

the

whether

or

not

there

t-test

was used

exists

farmers who

acknowledged that agricultural practices

significant

sources

disagree

sources
that

sources

of

of

of herbicides

environmental

of

pollution

agricultural

environmental

and

applied

pollution
those

practices

pollution

to

significant

in

other

rate

the

differences

to

the

responses,

by

those

relative

farmers

are

are

who

significant

relative

to

other

sources of pollution such as industries.
Research

Question

influence the

7:

To

what

extent

rate of herbicides

does

income

applied

by the

farmers?
The
after-taxes

respondents
annual

were

asked

farm income

to

In

this

study,

income

incomes of less than $15,000.

higher

income

$25,000.
(ANOVA)
exist

ranging

farmers

Based

on

Three levels of

and higher income were determined.

lower

those with incomes

their

from a list ranging from

"less than $10,000" to "above $60,000."
income, lower, middle,

indicate

the

are

farmers

are

those

with

Middle income farmers are

from $15,000 to
those

responses,

with

$25,000,

incomes

Analysis

and

above

of Variance

was used to determine if significant differences

in

the

rate

of herbicides

middle, and higher income farmers.

applied

between

lower,

81

Research Question 8 :
the

farm

To what extent does the size of

influence

the

rate

of

herbicides

applied?
The
acres

of

till.

respondents were

corn

The

they

planted

asked to indicate how many
in no-till

and

conventional

Pearson's Moment Correlation Coefficient was

subsequently

used

to

determine

statistically

significant

if

relationship

there
between

was
the

a
size

of the farm and the rates of herbicides applied.
Research

Question

continuous

9;

To

no-till

what

corn

extent

influence

do

years

in

the

rate

of

herbicides applied?
Respondents

were

asked

to

indicate

how

(years)

they have planted continuous no-till corn.

their

response,

Coefficient

was

the

Pearson's

used

to

Moment

determine

long
From

Correlation

if

there

is

a

statistically significant relationship between the number
of years a farmer has cultivated continuous no-till corn
and the rates of herbicides applied by the farmer.
One
information

drawback
is

the

of

utilizing

potential

for

and

farmer

is

expected

higher

rate of herbicide than recommended,
overapplication

Chances,

therefore,

to

responses.

admit

is
are

that

he

potentially
that

to

respondents

desirable

such

inaccurate

surveys

some

For
or

gather
to

give

example,

she

no

applied

a

especially if

against

the

of

responses

the

law.

82

obtained

in

this

study

might

have

been

socially

or

environmentally desirable answers to the questions in the
mailed

questionnaire.

questionnaires

were

interviews

might

especially

since

However,
used

have
the

the

fact

that

mailed

rather

than

face-to-face

minimized

such

a

anonymity

of

problem,

respondents

was

assured.
It

is

noteworthy

that

two

of

the

respondents

after being contacted by phone to clarify a response they
put down on their completed questionnaire requested that
the researcher "hold on for a moment" while they checked
their records to confirm the rates they had indicated in
the

questionnaire.

The

rates

they

indicated

after

consulting their records were the same as what they had
written down in the questionnaire,

thereby confirming the

accuracy of their initial answer on the questionnaire.
The exchange over the phone with the two farmers
was an indication that at least a few of the farmers do
maintain

good

records.

Such

minimizes

the

fear

of

desirable answers.
In conclusion,

Chapter

III

discussed

the

design

of the study including the population and its selection,
instrumentation,

administration

and

return

of

questionnaires and a brief description of the statistical
analysis

used

questions.

to

address

each

of

the

nine

research

CHAPTER IV
PRESENTATION AND ANALYSIS OF DATA
Introduction
This study attempted to determine whether or not
no-till

corn

herbicides
labels.

farmers

according

in
to

nine

Michigan

recommended

counties

rates

on

apply

container

This study also examined whether or not the same

no-till corn farmers apply the same rates of herbicide on
no-till and conventional till acreages.
From
Michigan
nine

a

list

counties,

Michigan

of

376

farmers

92 participated

counties

included

representing

in this

Berrien,

nine

study.

Cass,

The

Clinton,

Eaton, Hillsdale, Ingham, Ionia, Isabella, and Lenawee.
General Characteristics and Observations
The
ranged

in

92
size

no-till
from

average no-till corn
respondents,

65

corn.

range

acreages

The
was

from

1

corn
to

farms
2,700

acreage was

(or

70.7%)
in

13 to

size

also
of

1,000

used
acres

151

in
of

acres,

study

corn.

The

acres.

planted
the

this

Of the

conventional

conventional

corn

while the average

size of conventional corn acreage was 154 acres.

83

92

84

Table 4.1 shows the range of corn acreage, number
of responses,

and percentage of responses in no-till and

conventional tillage.

Table 4. 1.

Range of Acreages and Percentages of No-Till
and Conventional Till Acreages.

Conventional Till

No--Till
Acreage
No. of
Respondents

Percentage

No. of
Respondents

Percentage

1-199

73

79.3

47

72. 3

200-399

12

13.0

13

20.0

400-599

5

5.4

1

1.5

> 600

2

2.2

4

6.1

Total

92

100.0

65

100.0

Of
than

200

the

total

acres

of

92

farmers,

no-tiii

corn,

73

(or

while

79%)

47

(or

had
72%)

less
had

less than 200 acres of conventional corn acreages.
The number
no-till
presents

corn
the

of years

ranged
number

from
and

the respondents
0

to

22

years.

percentage

respondents have raised no-till corn.

of

have

raised

Table
years

4.2
the

85

Table 4.2.

Number
of
Years
in
Percentage of Responses

Years in No-Till

No-Till

Corn

Percentage

Number of Responses

5 or less

and

49

53.2

6-11

31

33.6

12-17

10

11.0

2

2.2

92

100.0

> 17
TOTAL

Of
no-till

the

corn

92

respondents,

for

five

years

49

or

(or 53%)

less

have

while

80

raised

(or

86%)

have raised no-till corn for eleven years or less.
The
recent

year

acreages.
the

respondents
they

tested

Table 4.3

respondents

were

asked

the

soil

to

indicate the most

in their

no-till

corn

shows the number and percentage of

according

to

the

year

they

tested

the

soil in their no-till corn acreages.
From

Table

4.3,

82

(or

89%)

of the

respondents

tested their no-till soil between 1985 and 1988.
Respondents

were

asked

to

indicate

the

soil

texture that best describes the texture of their no-till
corn

acres.

The

five

most

common

soil

textures

identified by the respondents are clay, clay loam, sandy

86

Table 4.3.

Most Recent Year the Respondents Tested
Soil in Their No-Till Corn Acreages

Year

Number of Responses

Prior to 1984

the

Percentage

3

3.3

1984

6

6.5

1985

13

14.3

1986

20

22.0

1987

35

38.5

1988

14

15.4

92

100.0

TOTAL

loam,

and

loamy

sand.

Table

responses by soil texture.

4.4 shows

the

number

of

As shown in Tables 4.4, clay

loam, sandy loam, and loam are the dominant textures.
Slightly

less

than

one-half

own

their no— t i l l

corn

own

their

corn acreages

rent.

no-till

Of

the

acreages.

respondents,

35

of

That

the

respondents

is,

43

(or

while only

14

(or 15%)

(or

38%)

indicated

46%)

that

they both own and rent.
The
call

or

respondents

visit with

were

their

asked

how many

Cooperative

times

Extension

or

Conservation personnel in an average month of thirty

they
Soil

87

Table 4.4.

Most
Common
Soil
Textures
Identified
Respondents and Their Percentages.

Soil Texture

by

Percentage

Number of Responses

5

5.4

Clay loam

31

33.7

Sandy loam

25

27.2

Loam

19

20.7

Loamy sand

6

6.5

Others

6

6.5

Clay

days.

The options given for the answers ranged from less

than two times in the month to more than ten times.
Table
telephone

calls

Conservation
84.8%)

of

4.5

shows
to

personnel.

the

the

number

Cooperative
As

respondents

of

visits

Extension

shown in Table

visit

with

and
4.5,

their

and
Soil

78

(or

Cooperative

Extension or Soil Conservation personnel twice or less in
an

average

month,

and

74

(or

80%)

have

two

or

fewer

contacts by telephone with their Cooperative Extension or
Soil Conservation personnel.
On
important)

a

rating

to "V"

scale

ranging

(very important),

from

"N"

(not

the respondents were

asked to rate the importance of each of the ten various

88

Table 4.5.

Number of visits
and Telephone Calls to
Cooperative Extension or Soil Conservation
Personnel per month.
Phone Calls

Personal Visits
NO. Of
Visits
and Calls

No. of
Respondents

< 2 times

78

84.8

74

80.4

2-4 times

11

12.0

12

13.1

5-7 times

3

3.2

1

1.1

8-10 times

0

0

4

4.3

> 10 times

0

0

1

1.1

sources

of information

No. of
Respondents

%

for the herbicides

%

they applied.

Table 4.6 shows sources of information for the herbicides
the

of

respondents

indicating "Very Important" for each source.

The number

of

farmers

applied

respondents

is

and

based

on

the

the

number

92

responses

from

the

survey.
From Table 4.6,
sources
labels,

of information for the respondents are container
chemical

Conservation
other

it is indicated that the top six

farmers,

and

Service,
friends,

fertilizer
Cooperative

salespeople,
Extension

relatives or neighbors,

Conservation District Directors.

Soil

Service,
and Soil

89

Table 4.6.

Source
of
Information
for
Herbicide
Application
and
Number
of
Respondents
Indicating "Very Important" for each source.

Respondents Indicating
"Very Important"
Source of Information

No. of
Respondents

Percent

Container Labels

61

66.3

Chemical and Fertilizer
Salespeople

38

41.3

Soil Conservation
Service

34

37.0

Cooperative Extension
Service

29

31.5

Farmers, friends,
relatives or
neighbors

19

20.6

Soil Conservation
District Directors

18

19.6

Farm magazines and
newspaper

7

7.6

Equipment Company
representative

3

3.3

Radio or Television
Programs

2

2.2

Local newspapers

1

1.1

*Number of respondents and percentages based on
92 responses indicating "Very Important" for each source
of information.

90

It
chemical

is worth

and

exploring

fertilizer

why

container

salespeople

rank

labels

and

as the highest

source of information as compared with Soil Conservation
Service
This

(SCS)

and

researcher

(herbicide)
chemical

Cooperative

contends

sales

Service

(CES).

that proximity to the chemical

depot

salespeople

Extension

and

could

the

have

aggressiveness
been

important

of

the

reasons.

The researcher, however, contends that the most important
reason possibly
(herbicide)

is that while on location at a chemical

sale depot,

the

farmer

is

able

to purchase

the herbicides he or she needs, and at the same time,
able

to

obtain

herbicide

(or

clarify

application

some)

from

the

information
chemical

is

regarding

salespeople.

This is quite unlike SCS and CES officials who can only
provide

information

regarding

do not sell the herbicides.
two

birds

with

one

herbicide sales depot.
contact

chemical

herbicide

information

but

Thus, the farmer could "kill

stone"

while

on

In addition,

(herbicide)

location

at

a

the farmer may also

salespeople

over

the

phone

rated

other

if he or she chooses to do so.
A
sources
farm

smaller

as

"very

magazines

representative,
newspapers.
respondents,

percentage
important."
and

of

respondents
These

newspaper,

other

sources

equipment

radio and television programs,
For

example,

respectively,

only

perceived

2%

and

1%

are

company
and local
of

the

radio or television

91

programs
of

and

local newspapers

information

suggests

for

that

(television,

herbicide

fiscal

radio,

as very

important

application.

resources

and newspapers)

sources

The

result

on

media

spent

for advertisement by

chemical companies should be redirected elsewhere.
Although
single
the

source

of

responses

federal

and

container

labels

information

obtained

provide

for

herbicide

indicate

state supported

the

that

services

a

primary

application,

combination

and agents,

of

namely

Soil Conservation Service, Cooperative Extension Service,
and

Soil

source

Conservation

of

information

container

labels.

government

supported

as

sources

However,

District

of

such

for

Directors

herbicide

The results
services

information
information

a

herbicide

than

that

being widely

services

larger

application

suggests

are
for

is

the

utilized

application.

are

not

if

they

being

fully

utilized.
The
herbicides
till acres.
that

more

conventional

respondents
are

applied

were

asked

to no-till than

to

think

more

conventional

Of the 92 respondents 54 (or 58.7%) believe
herbicides
till.

are applied

When

asked

if

in

no-till

they

apply

than
the

in
same

amount of herbicides to the same acreages each year, 49
(or

53%)

indicated

they apply

the

same

herbicides to the same acreages every year.

amount

of

92

The

respondents were

ranging

from

reasons

for

their

"Very
the

no-till

asked

to rate

Important"

amount of

corn.

Each

to"Not

herbicides
of

the

on

a

scale

Important,"

they

reasons

applied
had

the
in

options

spanning from the most important to unimportant.
Table

4.7

shows

the reasons

herbicides applied by the farmers,
of

respondents

and the

for

the

amount

of

as well as the number

percentage

that indicated

"very

important"

for each reason.

three most

important reasons why the respondents applied

the

of herbicides

amount

corn are:

As shown in Table 4.7,

they

applied

in

their

the

no-till

the type of weed, desire to increase farm

profitability,

and

the

desire

to

increase

crop

production.
The

respondents were

asked

to indicate

factors

that would cause them to apply less herbicides than they
applied

in the previous year.

in an order

of

importance

Their

ranging

response was

based

from "Very Important"

to "Not Important" for each selected reason.
Table
reduction

4.8 shows

inthe

amount

factors
of

that would

herbicides

cause

applied

in

a
the

current year compared to the previous year and the number
and percentage of the 92 respondents that indicated "Very
Important"
4.8,

for each factor or reason.

the primary

reasons

why

the

As shown in Table

respondents

less herbicides than in the previous year are:

would

use

93

Table 4.7.

Reasons for the Amount of Herbicides Applied
Based on the Number of Repondents for each
Reason

Respondents Indicating
"Very Important"
Reason for Amount
Applied
No. of
Respondents

Percent

Type of Weed

69

75.0

Desire to increase farm
profitability

60

65.2

Desire to increase
crop production

44

47.8

Personal farming
habits

25

27 .2

Advice from chemical
and fertilizer
sales agent

19

20.7

Advice from Local
Soil Conservation
District

16

17.4

14

15.2

Advice from Local
Cooperative Extension
*
J.ny o n

*Number of respondents and percentages based on
92 responses indicting "Very Important" for each reason.

94

Table 4.8.

Factors that would cause a reduction of use
of herbicides than in the previous year
Respondents
Indicating "Very
Important"

Factors for Using Less Herbicide

No. of
Resondents

Percent

Concern for surface and
groundwater contamination in
farmer's locality

43

46.7

Personal concern about potential
injury from herbicide
application

31

33.7

Concern for a potential rule
violation

29

31.5

Advice from a chemical
salesperson

26

28.5

Higher cost of herbicides in
the current year

9

9.8

Advice from a fellow farmer

6

6.5

*Number of respondents and percentage based on
responses indicating "Very Important” for each factor.

92

95

1.

Concern

for

surface

and

groundwater

contamination in th*ir locality
2.

Personal

concern about potential

injury from

herbicide application
3.

Concern for a potential rule violation

The farmers were asked whether or not they think
agricultural

practices

environmental

pollution

are

relative

pollution such as industries.

Table 4.9.

significant
to

other

sources

of

sources

of

Table 4.9 shows the number

Responses to Whether Agricultural Practices
are
significant
Sources
of
Environmental
Pollution Relative to other Sources Such as
Industries

No. of Repondents

Response

Percent

Yes

33

35.8

No

57

62.0

2

2.2

92

100.0

NonResponse
Total

of the responses to whether or not agricultural practices
are

significant

relative

to

other

sources
sources

of

environmental

such as

industries.

pollution
It

also

shows that of the 92 respondents, 33 (or 35.8%) perceived

96

that

agricultural

practices

are

significant

sources

of

environmental pollution while 57 (or 62%) disagreed.
With
respondents,

regard

to

the data

the

level

indicated

of

that

education
almost

of

all

respondents are high school graduates and more.
respondent

had

less

than

a

high

school

the

the
92

Only one

degree.

Table

4.10 shows the number and percentage of the respondents'
educational level.

Table 4.10.

Level of Education of Respondents

No. of
Respondents

Level

Less than High
School

Percentage

1

1.1

High School Degree

47

51.1

2-Year Vocational
Degree

12

13.0

Undergraduate
Degree and Above

31

33.7

Nonresponse

__1

1.1

Total

92

100.0%

The respondents were asked whether they are full­
time

farmers

or

were

defined

as

part-time
those

who

farmers.
derive

all

Full-time
sources

farmers
of

their

97

income

from

farming

while

part-time

farmers

were

those

who had other sources of income besides farming.
Table 4.11 shows respondents

indicating they are

full-time or part-time farmers.

Table 4.11.

Number of Respondents
Indicating Whether
They Are Full-time Farmers
or Part-time
Farmers

Levels

No. of Respondents

Percentage

Yes*

73

79.3

No

18

19.6

1

1.1

Nonresponse

*Yes indicates full time; no indicates part time.

As

shown

in

Table

4.11,

73

(or

79.3%)

of

the

respondents indicated they are full-time farmers compared
to

18

(or

19.6%)

that

indicated

they

are

part-time

farmers.
Of the 92 farmers, the data indicated that 27 (or
29%)

were unwilling

Tables
and

4.12

the

shows

number

to

the

and

answer
income

income-related
levels

percentage

of

of the

questions.
respondents

respondents

in

each

income level.
As shown in Table 4.12, of the 65 respondents who
indicated their after-taxes income, 20 (or 30.8%)

98

Table 4.12.

Income Levels of Respondents and the Number
and Percentage of Respondents In Each Income
Level
No. of
Respondents

Levels

Percentage

Below $15,000

10

15.4

$15,000-$24,999

10

15.4

$25,000-$34,999

21

32.3

$35,000-43,999

11

16.9

$44,000-49,999

5

7.7

$50,000-59,999

1

1.5

> $60,000

7

10.8

Non-Response

27

Total

92

indicated

an

income

below

100.0%

$25,000.

Thirty-seven

(or

56.9%) showed income between $25,000 and $49,999, while 8
(or 13%) hod income levels above $50,000.
All

the

conventional

herbicides

till

were

applied

tabulated.

in

no-till

Only

the

and
most

frequently applied herbicides used by at least 19 farmers
were selected for further analysis in this study.
4.13

shows

the

frequency

of usage of

type of tillage and time of application.

herbicides

Table
and

by

99

Table

4.13

herbicides

and

herbicides

in

frequently

applied

metolachlor,
emergence
herbicide

shows

the

number

no-till

of

and

atrazine

most

frequently

respondents

conventional

herbicides

paraquat,

in

the

were

glyphosate,

was

the

both no-till

and

applied

applying

the

till.

The most

atrazine,

cyanazine,

and

most

alachlor.
commonly

conventional

Pre­
applied

till

and

it

was the one herbicide for which 27%, or over one-fourth,
of the farmers apparently applied beyond the recommended
rate.
trade

Table
name

4.14

of

illustrates

the

most

the

common

frequently

name

applied

and

the

herbicides

identified by the respondents.
The
presentation
research

remaining
of

the

part

of

findings

questions.

A

this
for

brief

chapter

each

of

is

the

description

a

nine

of

the

statistics used and the findings will be presented.
Research Question 1
Research

Question

1.

To what

extent

do

herbicides

applied by no-till corn farmers in nine Michigan
Counties

conform

with

the

recommended

rates

on

container labels?
Table
standard

4.15

shows

deviation

range of recommended

of

the mean

the

(in lbs/acre)

applied

herbicides

and the
and

the

rates in active ingredients for the

four herbicides applied in no-till and conventional till.

100

Table 4.1 3 .

Most F r e q u e n t l y A p p l i e d H e r b i c i d e s and t h e Number o f
R e s p o n d e n t s A p p l y i n g t h e H e r b i c i d e s i n N o - t i l l and
C o n v e n t i o n a l T i l l Corn

Conventional T i l l

N o-Till

H erbicide

Pre­
emergen ce

Post­
em er gen ce

Preplant

Pre­
em er gen ce

Post­
emergence

No. o f R e s p o n d e n t s 9

Atrazine

63*

7

25*

39*

8

C y a n a z in e
(Bladex)

20*

3

4

13

1

M etolachlor
(Dual)

19*

1

4

12

1

Paraquat
(Gramoxone
Super)

20*

0

0

0

0

Glyphosate
(Roundup)

25*

0

0

0

0

A lachlor
(Lasso)

29*

2

9

18

2

^ In d ic a te s those s e le c te d f o r f u r t h e r a n a ly s is in t h i s study.
aBased on 92 r e s p o n s e s .

101

Table 4.14.

Common
and
Trade
Names
of
the
Most
Frequently Applied Herbicides Identified by
the Respondents.

Common Name

Trade Name

Atrazine

("Several")

Cyanazine

Bladex

Metolachlor

Dual

Paraquat

Gramoxone Super
(Gramoxone Extra)

Glyphosate

Roundup, Ranger

Alachlor

Lasso, Arena, MicroTech Lasso

Source:

1990 Weed Control Guide for Field Cro p s .
Cooperative Extension Service, Michigan State
University.

Table 4.15.

Comparison Between Actual and Recommended Herbicide Rates and Comparison Between No-till and Conventional Till
Applications
No-Till

Herbicide

N

Actual Rates

Rec. Rate*

xa

S.D.a

Active
Ingredients3

(a.i.)

Conventional Till
Percentage
Below

Atrazine

62

2.580

1.572

1.98 - 3.0

44

Cyanazine
(Bladex)

22

2.656

1.129

1.23 - 5.4

Metolachlor

18

2.056

0.539

Alachlor
(Lasso)

28

2.179

0.593

Within

Actual Rates

N

Xa

Above

(a.i.)

a.i. - Active Ingredients

Percentage

S.D.a

Active
Ingredients3

Below Within

Above

29

27

30

2.771

1.447

1.98 - 3.0

26.7

40.0

33.3

4.5

95.5

—

13

2.576

1.428

1.20 - 5.4

23.1

76.9

—

2.03 - 3.0

5.6

88.8

5.6

13

1.958

0.753

2.00 - 3.00

41.7

50.0

8.3

2.03 - 4.0

14.0

86.0

——

18

2.261

0.469

2.00 - 4.0

5.6

94.4

*Recommended rate in active ingredients (converted from volume reconnended rates)
"N lbs/acre)

Rec. Rate*

"

103

For each of the herbicides listed,
and

the

percentage of

below,

within,

indicated.

and

farmers

above

the recommended rate,

who

the

applied

herbicides

recommended

range

was

The range of recommended rates were based on

Crop Protection Chemicals Reference (1988) which contains
recommended

rates

of

herbicides

as

stipulated

on

container labels by various herbicide manufacturers.
The

range

consideration

of

the

recommended

formulation

rates

of

the

takes

into

herbicide,

the

organic matter content of the soil, and the soil texture.
The

recommended

herbicide

was

formulations
farmers

range

who

of

active

derived

and

from

applied

by

ingredients

conversion

the

results, the

herbicides

below,

the recommended rates were determined.
active
each

ingredients was done

soil

4=15

type.

Among

indicated

atrazine

that

applied

rates

from

of

the

below the

each

volume

percentage

within,

and

of

above

The conversion to

for each respondent

the no-till

44%

for

corn

and

farmers,

farmers

who

recommended

for

Table

applied

rates;

29%

of them applied atrazine within the range of recommended
rates,

while

27% applied

above the

range of recommended

rates.
Of

the

respondents

who applied

cyanazine

in NT,

95.5% applied the herbicide within the recommended rates;
4.5% applied the herbicide below the range of recommended
rates;

while

88.8%

of

those

who

applied

metolachlor

104

did so within recommended rates,

and 5.6% of the farmers

applied metolachlor below recommended
5.6%

of

the

farmers

applied

rates.

the

Similarly,

herbicide

above

recommended rates.
Table 4.15 also shows that in no-till corn, 86.0%
of

the

range,

farmers
while

recommended

applied
14.0%

range.

alachlor

within

the

applied

the

herbicide

None

the

alachlor

of

recommended
below
was

the

applied

above the recommended range.
In preemergence
farmers

applied

conventional

atrazine

rates.

However,

40%

within

recommended

below the

of

the

range,

till,

of

the

range of recommended

farmers

while

26.7%

28%

applied
applied

atrazine
above

the

range of recommended rates.
Application
recommended rates
23.1%

applied

while

76.9%

of

of

cyanazine

was

below

in conventional till.

cyanazine
the

below

respondents

the

and

Of the farmers,

recommended

applied

within

the

rates,

herbicide

within recommended rates.
Regarding alachlor,
it

within

the

range

of

94.4% of the farmers applied

recommended

rates,

while

5.6%

applied alachlor below the range of recommended rates.

105

Research Question 2
Research

Question

2.

applied

by

rates

conform

with

To
the

what
same

herbicide

extent

do

no-till

rates

herbicide

corn

they

farmers

applied

on

conventional till corn acres?
As

illustrated in Table 4.15,

deviation,
computed.
of

and

the

range

of

the mean,

recommended

who

applied

herbicides

below,

above recommended rates was compiled.
26.7%

of

conventional
rates

for

farmers

rates

were

For each of the herbicides also the percentage

farmers

4.15,

standard

the

farmers

till applied

preemergence,

applied

recommended

who

and

As shown in Table

applied

atrazine

in

it below the range recommended
while

atrazine within

rates

within,

40.0%

and

and

above

respectively

33.0%
the

for

of
range

the
of

preemergence

conventional till.
Furthermore,
there

is

a

herbicides

the t-test was used to determine if

significant
applied

to

difference
no-till

in

versus

the

rates

of

conventionally-

tilled acreages.
Table

4.16

shows

the

t-test

result

for

the

difference between herbicide application rates in no-till
and

conventional

similar

rates

of

till.

As

indicated

in

Table

atrazine,

alachlor,

cyanazine,

4.16,
and

metolachlor were applied by the farmers in NT and CT corn
acres.

There were no statistically significant

106

Table 4 .1 6 .

T - t e s t R e s u l t f o r t h e D i f f e r e n c e Between H e r b i c i d e A p p l i c a t i o n
R a t e s i n N o - T i l l and C o n v e n t i o n a l T i l l a g e ( u s i n g T - t e s t
com parisons).

H erbicide

N

A trazine

A lachlor
(Lasso)

Cyanazine
(Bladex)

M etolachlor
(Dual)

a .i.

Mean
(lbs/
acre)
(a.i.)

S td.

t-V alue

P-Value

0.16

0.872

1.41

0.178

-0.66

0.526

0.00

0 .0 0 0

N o-till

28

2 .8 21 1

1.585

Conventional

28

2. 7 9 0 7

1.441

N o-till

16

2 .2 5 0 0

0.438

Conventional

16

2.200

0.453

N o-till

10

2 .5 8 4 0

1 .2 8 4

Conventional

10

2 .7 3 4 0

1 .3 9 7

N o-till

9

2. 1111

0 .7 8 2

Conventional

9

2 .1 11 1

0.782

« active ingredient

107

differences
herbicides
contrary
who

observed
in

to

agreed

NT

at 0.05

and

CT

corn

the perception
that

more

level

for

acres.

by

58.7%

herbicides

are

all

the

This

applied

finding

is

of the

respondents

applied

in no-till

than in conventional till.
Research Question 3
Research Question 3 .
of

education

To what extent does the level

influence

the

rate

of

herbicides

applied by the farmers?
A
of

the

t-test was used

difference

in

to determine the significance

the

rate

of

herbicides

applied

between those farmers with a high school degree and less,
and those with above high school education.
Tables

4.17

and

4.18

show

the

t-test

result

of

active ingredients or rate of applied herbicides by level
of education in no-till and conventional till.
As shown in Tables 4.17 and 4.18, no significant
differences were found in either no-tlil or conventional
till with regard to the
the

levels

of

rates of herbicides

education.

Consequently,

applied and
the

results

indicate that levels of education of the respondents did
not influence the rates of herbicides they applied since
the

respondents

applied

similar

no-till and in conventional till.

rates

of

herbicides

in

108

Table 4.17.

H erbicide

A trazine

T-test Result: Active Ingredient (herbicides) by Level of
Education: No-Till only.

De mographic
V ariable

Education

39
23

Cyanazine

Education

9
13

M etolachlor Education

13
5

Gramoxone
Super

Education

14
6

Glyphosate

Education

11
12

Alachlor

Education

13
15

a .i.

Levels

Mean
(lb s/
acres)
(a .i.)

Std.

T- V a lu e

High S c h o o l /
Below
>High School

2 .4 5 9 2

1.524

-0.82

0.415

2. 8 0 7 8

1.660

High S c h o o l /
Below
>High Sch oo l

2.9778

1. 2 1 8

1.09

0.294

2.4338

1.054

High S c h o o l /
Below
>High Sc ho ol

1. 92 31

0.277

-1.17

0 .3 0 2

2.400

0.894

High S c h o o l /
Below
>High Sc ho ol

0.6696

0.358

-0.35

0.7 3 1

0.7188

0.249

High S c h o o l /
Below
>High Sc ho ol

1.6364

0.452

-0.27

0.792

1.6875

0.466

Hi gh S c h o o l /
Below
>High Sc ho ol

2.1538

0.555

0.09

0.933

2.1333

1.453

N

- active ingredient

2-T ail
Prob.

109

Table 4.18.

H erbicide

Atrazine
(PREM)

Cyanazine

T-Test Result: Active Ingredient (herbicides) by Level o£
Education: Conventional Only

Demographic
V ariable

Education

Education

M etolachlor Education

A lachlor
(Lasso)

Education

Levels

Mean
(lb s/
acres)
(a.i.)

Std.

17

H igh S c h o o l /
Below

2.8376

1.7 4 2

13

>High Sc h o o l

2.6848

1.0 0 2

6

High S c h o o l /
Below

2.1583

1 .3 11

7

>High Sc h o o l

2 .9 3 4 3

1.525

6

High S c h o o l /
Below

1. 8333

0.408

6

>High Sc h o o l

2 .0 8 3 3

1.021

6

High S c h o o l /
Below

2.1167

0.449

12

>High Sc ho ol

2 .3 3 3 3

0.481

N

T- V a lu e

2-T ail
Pr o b .

0.30

0.765

-0.99

0.345

-0.56

0.596

0.94

0 .3 6 7

110

Research Question 4
Research Question 4 .
or

rental

of

To what extent does ownership

farmland

influence

the

rate

of

herbicides applied by the farmers?
The

three

questionnaire

levels

are

of

"own,"

ownership

"rent,"

in

and

the

survey

both."

The

respondents were asked if they own or rent their no-till
corn acres or whether they both own and rent.
Analysis
determine

if

of

Variance

significant

(ANOVA)

differences

was

used

to

exist

in

the

herbicide rates applied by those farmers who strictly own
their no-till corn

acres

and those who exclusively

their

acres

as

no-till

corn

well

as

those

who

own

rent
and

rent their no-till corn acres.
Tables
results
as

conventional

with

and

of the applied

the mean

level

4.19

and

found

regard

to

in
the

show

Analysis

of

Variance

herbicides by ownership,

the standard

till.

was

4.20

No
both

deviation

significant
no-till

influence

for

and

at

0.05

conventional

till

of ownership

the rates of herbicides applied.

no-till

difference

and

as well

Therefore,

or

rental on

whether the

farmer owns or rents the farm does not have any influence
on

the

rates

of herbicides

and those who rent

applied

since those

who

own

apply similar rates of herbicides to

their no-till and conventional till acreages.

Ill

Table 4 .1 9 .

ANOVA R e s u l t s o f H e r b i c i d e s by O w ne rs hi p ( N o - T i l l Only)

H erbicide

Demo
V ariable

A trazine

Cyanazine
(Bladex)

Metolach
lor
(Dual)

Ow nership

Own ership

Owners hi p

Paraquat
Own ership
(Grarooxone
Super)

G l y p h o s a t e Own ers hi p
(Roundup)

A lachlor
(Lasso)

a .i.

Owners hi p

Mean
(lb s/
acre)
(i.a .)

N

Levels

23

Own

2.7613

1 .9 2 9 0

11

Ren t

2.0800

1 .1 2 4 9

28

Both

2 .6 4 6 4

1. 3 9 5 3

9

Own

2 .4 3 7 8

1. 3 0 0 7

1

Re nt

2 .0 0 0 0

1 .0 3 6 5

12

Both

2 .8 7 5 0

1.1294

7

Own

2 .0 0 0 0

0.0000

1

Rent

2 .0 0 0 0

0.7379

10

Bo th

2.1000

0 .5 3 9 3

10

Own

0.6375

0.2958

4

Rent

0.7031

0.5386

6

Both

0.7500

0 .2 3 7 2

Own

1.6500

0.4205

2

Ren t

2 .2 5 0 0

1. 06 07

7

Bot h

1.5000

0.0000

Own

2.2708

0.6524

5

Rent

1. 9 0 0 0

0.5477

11

Bo th

2.1136

0.6649

15

12

■ activ e ingredient

Std.

F

0.7271

Value

0. 4 8;

0 .5 3 7 5

0.5928

0.0680

0.9345

0.2158

0 .8 08 1

2 .5 5 6 6

0 .1 0 1 5

0.6076

0.5525

112

Table 4.20.

ANOVA R e s u l t s o f H e r b i c i d e s by O w ne rsh ip ( C o n v e n t i o n a l Only)

H erbicide

Demo
V ariable

A trazine
(PREM)

Cyanazine
(Bladex)

M etolachr
low
(Dual)

A lachlor
(Lasso)

a.i.

O w ne rsh ip

Ow ne rs hi p

O w ne rs hi p

Ow ne rs hi p

N

Levels

Mean
(lbs/
acre)
(a .i.)

Std.

F

Value

0.7074

0. 5 0 1 8

0 .0 0 9 9

0.9225

0.0075

0.9925

0 .3 8 0 2

0 .6 9 0 1

9

Own

3.2044

2.1754

5

Rent

2.2800

0.9550

16

Both

2.6812

0.0400

6

Own

2.5317

1.5031

7

Both

2.6143

1 .4 8 1 5

3

Own

2 .0 0 0 0

1.-000

1

Rent

2 .0 0 0 0

.00

8

Both

1 .9 3 7 5

0.9425

8

Own

2 .3 4 2 8

0 .5 1 6 5

3

Rent

2 .3 3 3 3

0.5774

7

Both

2. 1 3 5 7

0 .4 1 3 0

- active ingredient

113

Research Question 5
Research

Question

status

5:

To what

(full-time

or

extent

part-time)

does

farming

influence

the

rate of herbicides applied in no-till corn acres?
The

respondents

were asked

whether

were full-time or part-time farmers.
separately

for

no-till

and

or not

they

The t-test was used

conventional

till

responses

to determine whether or not significant differences exist
in the rates of herbicides applied by full-time and parttime farmers.
Tables

4.21

indicates

the

t-test

result

of

applied herbicides by farming status for no-till corn.
As
difference

shown
at

Consequently,
did

not

applied

inTables

0.05

4.21,

level was

no significant
found

in no-till.

whether a farmer is full time or part time

have

any

since

influence

full-time

on

and

the

rate of

part-time

herbicides

no-till

corn

farmers applied similar rates of herbicides.
Research Question 6
Research

Question

environmental

6:

To

awareness

what

extent

influence

do
the

farmers;
rate

of

herbicides they applied?
The

respondents

were asked

whether

or not

they

think agricultural practice is a significant source of

114

Table 4.21.

H erbicide

Atrazine

Cyanazine
(Bladex)

T-Test Result: Herbicides (active ingredients) by Farming
Status (Full-Time vs. Eart-Time) (No-till Only)

Demographic
V ariable

F-Status

F-Status

M etolachlor F -S tatu s
(D ual)8

Paraquat
(Gramoxone
Super)

F-Status

Glyphosate
(Roundup)

F-Status

A lachlor
(Lasso)

a .i.

F-Status

Levels

Mean
(lb s/
acres)
(a.i.)

Std.

50

Full-Time

2.5958

1 .6 8 0

12

Part-Time

2.5583

1 .0 6 3

19

Full-tim e

2 .4 8 6 3

1.114

3

Part-Time

2.400

0.693

16

Full-Time

2 .0 6 2 5

0.574

2

Part-Time

2 .0 0 0 0

0.000

18

Full-Time

0 .7 0 8 3

0.331

2

Part-Time

0 .4 6 8 8

0.133

16

Full-Time

1 .7 34 4

0.528

7

Part-Time

1 .5 0 0 0

0.000

24

F ull-tim e

2 .2 0 8 3

1.6 37

4

Part-Time

1 .7 5 0 0

1 .5 0 0

N

T- Va lu e

0.10

2-Tail
Prob.

0 .9 2 4

0.18

0 .8 6 5

0.0

0.0

0.0

0.0

1.78

0 .0 9 6

1 .6 3

0 .1 67

- active ingredient

t - s t a t i s t i c c o u l d n o t be computed due t o few s u b j e c t s i n g r o u p .

115

environmental pollution in their county relative to other
sources of pollution such as industries.
Table
applied

4.22

herbicides

(illustrated

by

and

4.23

by

level

"yes"

show
of

and

the

t-test

results

environmental

"no")

for

of

awareness

no-till

and

conventional tillage.
No significant differences were found with regard
to

the

amount

environmental

of

herbicides

awareness

indicates

that

practices

as

pollution

or

herbicides

applied since

of the

whether

a

significant
not

applied

and

respondents.
farmer

the two groups

of

result

agricultural

of

influence

level

The

saw

sources

did not

the

environmental
the

rates

applied

of

similar

rates of herbicides.
Research Question 7
Research

Question

influence the

7:

To

what

extent

rate of herbicides

does

income

applied

by the

farmers?
The
after-taxes

respondents

were

asked

indicate

their

annual farm income from a list ranging from

"less than $10,000" to "above $60,000."
least

to

willing

to

answer

this

Respondents were

income-related

The data show that there were 27 nonresponses
total 92 farmers.

question.
out of the

116

Table 4.22.

H erbicide

A trazine

Cyanazine
(Bladex)

T-Test Result: Herbicides (active ingredients) by
Environmental Awareness (No-till Only)

Demographic
V ariable

Environ.

Environ.

M etolachlor Environ.
(Dual)

Paraquat
(Gramoxone
Super)

Environ.

Glyphosate
(Roundup)

Environ.

A lachlor
(Lasso)

a.i.

Environ.

N

Levels

Mean
(lb s/
acres)
(a.i.)

Std.

T- V a lu e

1 .6 6

0.104

-1.32

0.232

-0.43

0.6 71

-0.18

0. 8 6 7

-1.76

0 .0 9 6

1.75

0.092

25

Yes

3 .0 1 9 6

1.941

35

No

2 .2 85 7

1 .2 3 6

5

Yes

2 .0 3 8 0

1. 161

15

No

2. 81 67

1.097

3

Yes

2 .0 0 0 0

0.0000

14

No

2 .0 7 1 4

0.616

4

Yes

0 .6 5 6 3

0 .3 5 9

16

No

0 .6 9 1 4

0.326

5

Yes

1 .5 00 0

0.000

19

No

1 .6 97 4

0.490

12

Yes

2 .3 7 5 0

0 .5 1 7

15

No

1. 96 67

0.694

- active ingredient

2-Tail
Prob.

117

Table 4.23.

H erbicide

A trazine
(EREM)

Cyanazine
(Bladex)8

T-Test Result: Herbicides (active ingredients) by
Environmental Awareness (Conventional Only)

Demographic
V ariable

Environ.

Environ.

M etolachlor Environ.
(D ual)8

N

Environ.

t-statistic
a.i.

Mean
(lb s/
acres)
(a.i.)

Std.

10

Yes

3.3400

1.946

19

No

2.4600

1 .0 9 4

2

Yes

2.3200

2.376

9

No

2 .6 2 2 7

1.3 6 7

1

Yes

2.0000

0.000

No

1. 9 5 4 5

0.789

9

Yes

2 .4 11 1

0.553

8

No

2.1250

0.354

11

A lachlor
(Lasso)

Levels

c o u l d n o t be computed due t o

* active ingredient.

T- V a lu e

1 .3 2

2-T ail
Prob.

0.210

0.0

0.0

0.0

1.29

0.0

0.220

s u b j e c t s in group.

118

Table

4.24

and

4.25

illustrate

the

Analysis

of

Variance result of herbicides by income levels in no-till
and conventional till.
As indicated in Tables 4.24 and 4.25, there were
no

significant

conventional
income

on

differences

till

the

with

rate

in

reference

of

both
to

herbicides

no-till

the

and

influence

applied.

The

of

only

significant difference was found in alachlor application
in no-till.
applied

more

farmers.
resulted
it

result

alachlor

Besides

showed
than

the

type

that mid-income

high

or

of

weed

low

farmers

income

which

corn

may

have

in more alachlor applied by mid-income farmers,

could

(first

The

also

or

be

that

second

the mid-income

year)

to no-till.

farmers

were

According

Ingham County District Soil Conservationist,

to

new
the

"it has been

shown that first-and second-year no-till farmers usually
apply

more

amount
For
low,

the

herbicides

applied drops
most

middle,

part,

in

off

those

early

years

in later years"

therefore,

whether

a

while

(Hielcs.
farmer

the

1989),
was

of

or high income did not influence the fates

of herbicides applied.

119

Table 4.24.

One way Analysis of Variance (ANOVA) Result of Herbicides
(Active Ingredient) by Income (No-till only)

H erbicide

Demo
V ariable

N

Atrazine

Income

13

<15,000

15

Cyanazine
(Bladex)

Income

M etolachlor
(D ua l

Paraquat
(Gramoxone
Supe r )

Glyphosate
(Roundup)

A lachlor

Income

Income

Income

Income

F

Value

2.8223

1 .7 09 7

1. 0 5 4 9

0 .3 5 7 7

15,000-24,999

2.8053

1.9762

15

>25,000

1.9980

1.5435

3

<15,000

3.2000

1 .3 8 5 6

0 .7 0 8 7

0.5091

5

15,000-24,999

2.1680

1.1988

9

>2 5,000

2.5278

1 .1 27 3

3

<15,000

2.000

0.000 0

1.0000

0. 3 9 6 6

7

15,000-24,999

2.2857

0.7559

5

>25,000

1.8000

0.4472

5

<15,000

0.8250

0.4889

0.3534

0 .7 0 8 8

5

15,000-24,999

0.6375

0.3137

6

>25,000

0.6875

0.2823

7

<1 5,000

1.8214

0.5901

0 .7 0 0 1

0 .5 143

5

15,000-24,999

1 .5 0 0 0

0. 0000

4

>2 5,000

1.8750

0.7500

7

<15,000

2.000

0.5774

4.0734

0 . 0328;

9

15,000-24,999

2.5278

0.5368

7

>25,000

1.8214

0.4261

* S i g n i f i c a n t a t t h e .0 5 l e v e l .
a.i.

Mean
(lbs/
acre)
(a.i.)

Std.

Levels

- active ingredients

120

Table 4.25

ANOVA Results of Herbicides by Income (Conventional Only)

Demo
V ariable

H erbicide

Income

A trazine
(PREM)

Levels

N

Income

Cyanazine
(Bladex)

Income

M etolachlor
(Dual)

a.i.

Income

Std.

F

Value

0.4622

0.6376

07667

0.4878

0.5999

0.5748

1. 3 7 7 8

0 .3 1 2 9

< 1 5 ,0 0 0

2.1100

0.7269

15,000-24,999

2.7308

1 .9 5 1 7

3

> 25 ,0 00

3.3333

0.5774

2

<1 5, 00 0

2.000

0.0000

9

15,000-24,999

2.3833

0.5679

3

>2 5, 00 0

2.0833

0.1443

3

<1 5, 00 0

3.2000

1. 3 8 5 6

5

15,000-24,999

2.0080

1.4534

2

>25 ,000

2.2500

1 .9 0 9 2

2

< 15 ,0 00

2.000

0.0000

5

15,000-24,999

2.3000

0.9747

3

>25 ,000

1. 33 33

0.5774

4
13

A lachlor
(Lasso)

Mean
(lbs/
acre)
(a.i.)

- active ingredient

121

Research Question 8
Research Question 8 :
the

farm

To what extent does the size of

influence

the

rate

of

herbicides

applied?
The
acres

of

respondents were

corn

conventional

they

planted

till.

Coefficient

was

statistically

asked

The

used

to

significant

to indicate how many

separately
Pearson

in

no-till

Moment

determine

if

relationship

and

Correlation
there

between

was
the

a

size

of the farm and the rates of herbicides applied.
Table

4.26

shows

the

result of the

relationship

between herbicide rates and the size of the farm in both
no-till and conventional till.
As

shown

in

Table

4.26,

no

significant

differences at 0.05 level were found in both no-till and
conventional
size

on

till

the

with

rate

of

regard

to

the

herbicides

applications

indicate

that

increase

in the rate of alachlor applied.

in

no-till

applied

alachlor

increase

in

influence

farm

corn.
size

of

farm

except

for

The

findings

corresponded

with

The increase

in alachlor applications with increase in farm size could
be due to the presence of more herbicide resistant weeds
which

induced

increases

in herbicide

rates applied.

it

could also be that the farmers were switching to no-till
for the first time and decided to apply more to ensure

122

Table 4.26.

Relationship Between Herbicide Rates with
Size of Farm (No-till and Conventional)
No-till

Conventional
•

Herbicide

N

Atrazine

62

-0.0570

Cyanazine
(Bladex)

22

0.296

Metolachlor
(D u a l )

18

r

P-Value

N

r

P-Value

0.330

45

0.1320

0.194

0.448*

15

0.1944

0.244

.0606

0.406

12

0.1357

0.337

20

.0289

0.452

Glyphosate
(Round-Up)

24

.0247

0.454

—

Alachlor
(Lasso)

28

0.4879

0.004*

21

Paraquat
(Gramoxone
Super

*Significant at the .05 level.

—

0.0845

—

0.358

123

returns on their investments, especially for land, labor,
and

other

inputs

such

as

herbicides,

fertilisers,

and

machinery.
Research Question 9
Research

Question

continuous

9:

To

no-till

what

corn

extent

influence

do

years

in

the

rate

of

herbicides applied?
The
(in

respondents were

years)

they

have

asked to

planted

indicate how long

continuous

no-till

corn.

The Pearson's Moment Correlation Coefficient was used to
determine

if

relationship
planted

there

is

between

the

continuous

a

statistically

number

no-till

of

corn

significant

years
and

a

farmer

has

the

rates

of

herbicides applied by the farmer.
Table

4.27

shows the

result of the

relationship

between years in continuous no-till corn and the rate of
herbicides applied by the respondents.
Results

on

Table

4.27

statistically

significant

application.

This

continuous no-till
applied.
which

This

suggests

herbicides

in

at

suggests
corn,

shows

that

0.05

level

alachlor
in

that the more the

the more the

was

no-till
years

in

rates of alachlor

finding disagrees with an earlier finding
that

no-till

the

early

farmers

years

usually

while

herbicides applied decline in later years.

the

apply
amount

more
of

Although the

124

Table 4.27.

Herbicide

Relationship between Herbicide Rates (Active
Ingredients) with Years of Experience with
Continuous No-Till Corn

N

r

P-Value

No-Till
Atrazine

62

-0.0481

0.355

Cyanazine
(Bladex)

22

0.1139

0.307

Metolachlor
(Dual)

18

0.0946

0.354

20

0.1409

0.277

Glyphosate
(Round-Up)

24

0.0688

0.375

Alachlor
(Lasso)

28

0.4337

0.011*

Paraquat
(Gramoxone
S u per)

*Significant at the 0.05 level.

125

finding

disagrees

with an earlier

finding,

it could

be

peculiar only with continuous no-till corn.
Doub et al.
dominant

annual

(1988) found that the "control of the

grass

species,

large

crabgrass,

by

alachlor declined to less than 50% by the fifth year of
continuous
reported

no-till
that

metolachlor
study,

(1988)

fall

metolachlor

continuous

annual

deficiences

no

till"

and

that

(1988)

80%

throughout

the

establishment

. .."

control

when

al.

by

"alachlor

grass

et

crabgrass

allowed

while

Doub

large

than

population.

that

excellent

of

greater

panicum

display

However,

"control

remained

concluded

provide
both

the

although

greater

corn."

Doub

et

a

al.

and

metolachlor

the

first

repeatedly
"high

of

year,

used

large

in

crabgrass

populations associated with continuous no-till management
may have been responsible for the low control by repeated
alachlor applications."
Triplett

jr.,

combinations

of

eliminating

weed

and

Lytle (1972)

herbicides
and

that

proved

most

"annual

found

that

only

satisfactory
weed

in

populations

shifted rapidly with different herbicide systems."
In

summary,

characteristics
as

a more

and

detailed

research questions.

Chapter

IV

observations
report of the

discussed

the

general

from the study

as well

findings

based

on the

CHAPTER V
SUMMARY, CONCLUSION, DISCUSSION, AND
RECOMMENDATIONS
Summary
Purpose
This

study

explored

the

reported

herbicide

application rates applied by no-till corn farmers in nine
Michigan

counties

applying

herbicides

container

and

labels

and

whether

or

not

according

to

recommended

what

influenced

the

farmers

were

rates

them

to

apply

this

study

on
the

rates of herbicides they applied.
Another
determine
same

primary

whether

rates

of

or

objective

not

the

herbicides

of

same

to

farmers

both

their

was

applied
no-till

to
the
and

conventional corn acreages.
Research Questions
The

following

research

questions

were

addressed

in the study:
Research

Question

applied
counties

l.

To what

extent

do

herbicides

by no-till corn farmers in nine Michigan
conform

with

the

container labels?

126

recommended

rates

on

127

Research

Question

2.

applied

by

rates

conform

with

To
the

what

extent

same

herbicide

do

no-till

rates

herbicide

corn

they

farmers

apply

on

conventional-till corn acres?
Research Question
of

3.

education,

(full

time

To what extent does the level

land

ownership,

versus

awareness,

income,

continuous

no-till

part
farm
corn

farming

time)
size,

status,

environmental
and

influence

years

the

in

rate

of

herbicides applied by the farmers?
It

is

worth

herbicide

noting

that

formulations

in

in

this

liquid,

study,

the

wettable

applied

powder,

and

water dispersible granule or dry flowables were converted
into active ingredients.
Population and Sample
There

were

376

farmers

listed

by

the

U.S.

Soil

Conservation Service as no-till corn farmers in the nine
counties

under

Clinton,

Eaton,

Lenawee.

Out

participate

in

study.

The

Hillsdale,
of the

376

this

study

mail questionnaire.

counties
Ingham,
listed
by

are Berrien,

Ionia,
farmers,

voluntarily

Cass,

Isabella,

and

92 choose
completing

to
a

128

Methodology
A survey questionnaire comprised of 29 questions
relating

to

attitudinal
answers

practice,

institutions,

and demographic

from

the

environmental/

factors was used

participants.

A mail

to solicit

survey was used

with follow-up reminders.
Statistical
(SPSSX)

was

survey.

used

were used
test,

analyze

analysis

and

results.

of variance

Social

Sciences

obtained

from the

statistics

means,

the

Correlation Coefficient

the

the data

descriptive

percentages,

to

for

to analyze

Simple

frequencies,

Package

(ANOVA)

ranging

standard

deviation

In addition,
and Pearson's

were utilized

in

from

the

t-

Moment

analyzing

data

and drawing conclusions.
The

following

is

a

summary

of

some

of

the

findings based on the response of the 92 respondents that
provided useable questionnaires.
Size of Farm
The
farm

for

the

respondents,
till

average

corn.

92
73
Of

amount

farms

was

(or 79%)
the

conventional till corn.

of no-till

92

151

corn

acres.

Out

had less than 200
respondents,

acreage

65

of

the

per
92

acres of n o ­
also

planted

The average size of conventional

corn acreage on the 65 farms was 154 acres.

129

Years In No-Till Corn
About one-half of the 92 respondents have planted
no-till
86%)

corn

for

five

years

or

less.

However,

80

(or

of the farmers have planted no-till corn for eleven

years or less.
Most Common Soil Textures
The three most common soil textures identified by
the

respondents

acreage

are

comprised

that

clay

33.7%,

best

describes

loam,
27.2%,

sandy
and

their

loam,

20.7%

no-till

and

of

loam.

the

corn
They

responses,

respectively.
Ownership of No-Till Acres
Slightly less than one-half of the 92 respondents
owned
46%)

their

no-till

corn

acres.

Specifically,

owned their no-till acres, while 14

from others.

Thirty-five respondents

(or 15%)

43

(or

rented

(or 38%) both owned

and rented their no-till corn acros.
Are More Herbicides Applied
In No-Till than in
Conventional Till?
Slightly over one-half of the respondents
that more herbicides are applied in no-till.
(or 58.7%)
till.
rates

That is, 54

agreed that more herbicides are applied in no ­

When
of

agreed

asked

herbicides

if

they

each

personally

year

to

the

applied
same

the

no-till

same
and

130

conventional acreages, 49 (or 53%)

indicated they applied

the same rates every year.
Summary of the Findings and Conclusions
Comparison Between Actual Rates
of Applied Herbicides and the
Recommended Rates
Research

Question

applied

1.

To what

extent do

herbicides

by no-till corn farmers in nine Michigan

counties

conform

with

the

recommended

rates

on

container labels?
Summary of findings:
reported

that

they

applied

Overall, the 92 respondents
herbicides

below

and

within

the range of recommended rates.
Of the atrazine applied in no-till corn,

7 3% was

applied below and within the range of recommended rates,
while 27% of the

applied atrazine was applied above the

range of recommended rates.
Of

the

cyanazine

applied

in no-till

corn,

was applied within the range of recommended rates.
cyanazine,

94.4%

of

below or within the

the

applied metolachlor was

range of recommended

100%
Like

applied

rates and 5.6%

was applied above the range of recommended rates.

the

Of

the

range

of

herbicide
rates.

was

paraquat

applied,

recommended
applied

above

80%

rates,
the

was

applied

while
range

of

20%

of

below
the

recommended

131

In no-till, also, 87.5% of the applied glyphosate
(Roundup)
rates.
4.15

was

Paraquat and

because

conventional
compared.
applied

applied

within

the

were

not

till

and

therefore

the

within

of

recommended

glyphosate were not shown on Table

they

Of

range

applied

the

range

used

by

the

cannot

alachlor
of

respondents
be

adequately

(Lasso),

recommended

in

86.0%

rates,

was

while

14.0% was applied below the range of recommended rates.
In

corn

preemergence

under

atrazine

range of recommended
of

the

applied

conventional
was

rates.

cyanazine

applied

below or within

Of

alachlor

the

applied

applied

tillage,
below

66.7%

or

within

Similarly to no-till,

in conventional

till

corn

the range of recommended
in conventional

till,

of
the
100%
was

rates.

100%

was

applied below or within the recommended rates.
Conclusion:

The reported rates of herbicides

applied by the 92 respondents were mostly below or within
the range of recommended rates on container labels.
Comparison Between Rates of
Herbicide Applied in No-Till
Corn and Rates of Herbicide
Applied in Corn under'
Conventional Tillage
Research
rates

Question

2.

applied

by

conform

with

To
the

what
same

herbicide

extent
no-till

rates

conventional till corn acres?

they

do

herbicide

corn

farmers

applied

on

132

Summary of Findings;
conformity
herbicides

in

herbicide

applied

The data show there was

namely

application
atrazine,

rates

alachlor,

for

the

cyanazine

and metolachlor applied in both no-till and conventional
till.

No

statistically

significant

differences

were

observed for the reported rates applied in corn under no­
till and conventional till.
Conclusion:
58.7%)

and

herbicides

Contrary to the

other
are

sources

applied

to

54 respondents (or

that

believe

no-till

than

to

that

more

conventional

till, this study showed that similar rates of herbicides
were applied in both no-till and conventional till.
Influences of Selected
Demographic variables on
Applied Herbicide Rates
Research Question
of

education

applied

3.

To what extent does the level

influence

by

the

the

rate

farmers

in

of

herbicides

no-till

and

conventional till corn?
Summary of Findings:
determine
existed

if

between

statistically
the

The

significant

less-educated

respondents with regard
applied.

A t-test was used to

result

significant differences

to

and

the rates
showed

the more-educated
of herbicides they

that

at 0.05 level

differences

there

were

no

between the less-

133

educated

and

the more-educated

respondents

in regard to

the rates of herbicides applied by the respondents.
Conclusion:
respondents

did

The level of education of the

not

make

any

difference

influencing the rate of herbicides applied.
herbicides
educated

applied

were

by

the

similar

and

less
no

educated

one

group

in

terms

of

The rates of
and

the

applied

more

either

more or less than the other.
Research Question
or

rental

4.

of

To what extent does ownership

farmland

influence

the

rate

of

herbicides applied by the farmers in no-till and
conventional till?
Summary of Findings:

Analysis of Variance was

used to test for statistically significant differences in
the

rates

of herbicides

the

land

they

operated,

and

operated,
those

who

applied

between those who owned

those who
did

both.

rented
The

the land
result

they

showed

there was no significant difference among those who owned
and

operated their land,

and those who rented land

from

others, and those who did both.
Conclusion:

Whether a farmer owned his farm or

rented it or both did not have any influence on the rates
of herbicides applied.

134

Research

Question

status

5:

To

(full-time

or

what

extent

part-time)

does

farming

influence

the

rate of herbicides applied in no-till corn acres?
Summary of Findings:
determine
in the
and

if statistically

rates

result

farmers

showed

observed

significant differences

of herbicides

part-time

that

to
no

in no-till

The t-test was used to

applied by full-time
no-till

corn

significant

for

full-time

exist

farmers

acreage.

The

differences

were

and part-time

farmers

in regard to the rates of herbicides they applied.
Conclusion;
applied
is

In all cases, the rate of herbicides

in no-till did not depend on whether the farmer

a full-time

or

part-time

farm operator,

since

both

full-time and part-time farmers applied similar rates of
herbicides.
Research

Question

environmental

6:

To

what

awareness

herbicides

they

extent

influence

applied

in

do

farmers'

the

rate

no-till

of
and

conventional till corn?
Summary

of

findings:

determine

if statistically

in

rate

the

of

environmentally-aware
environmentally

aware

conventional

till

A

t-test

was

used

to

significant differences exist

herbicide

applied

respondents
respondents.
herbicide

from

by

the
the

more
less-

In both no-till
applications,

and
no

135

statistically

significant

difference

was

found

between

the more environmentally aware respondents and the lessenvironmentally

aware

respondents

with

regard

to

the

rates of herbicides they applied.
Conclusion.

Whether a farmer was environmentally

aware or not that pesticides
environmental pollution

are significant

in their

sources of

county did not have an

influence on the rates of herbicides they applied.
Research

Question

influence

the

7:

To

rate

what

extent

of herbicides

does

income

applied

by the

farmers in no-till and conventional till corn?
Summary of findings:
used

to

differences
group

determine
exist

farmers

if

among

in

the

Analysis of variance was
statistically

high,
study

middle,
with

significant

and

low

reference

to

income
their

herbicide application rates for the different herbicides.
In general, there was no significant difference among the
three

income

groups

with

herbicides they applied.
(Lasso)
farmers

application
applied

regard

the

rates

of

The only exception was alachlor

in no-till

higher

to

where

rates.

An

the

middle

unnamed

income

District

Conservationist in one of the counties surveyed suggested
that is not uncommon that mid-income farmers would apply
higher

rates

of

alachlor

because

"mid-income

to

high-

136

income

farmers

tend

to

always

include

a

fall

grass

herbicide such as alachlor or metolachlor."
Conclusion:

In almost all cases, income level

had no influence on the rates of herbicides applied.
Research Question 8 :

To what extent does the size of

the farm influence the rate of herbicides applied
in no-till and conventional till?
Summary of Findings:
Correlation

Coefficient

were statistically

was

The Pearson's Moment
used

to

determine

significant relationships

if

there

between the

size of the farm and the rate of herbicides applied.
significant
size

of

the

relationships were
farm

and

The only exception
which

was

found

the

was
to

found with regard

rates

of

herbicides

size

have

increased.

increased,
This

to the

applied.

alachlor application in no-till
a

statistically

relationship with the size of the farm.
farm

No

the

exception

rate
may

of
have

significant

Consequently, as
applied
been

due

alachlor
to

the

presence of more herbicide resistant weeds.

Conclusion:
of

the

farm did

not

herbicides applied.

In almost every instance, the size
have

any

influence

on

the rate of

137

Research

Question

continuous

9:

To

no-till

what

corn

extent

influence

do

years

in

the

rate

of

herbicides applied?
Summary of findings:
Correlation

Coefficient

The Pearson's Moment

was

used

to

determine

if

statistically significant relationship exists between the
number of years in continuous no-till corn and the rates
of

herbicides

statistically

applied.

The

significant

result

indicated

relationship

for

a

alachlor

applications at 0.05 level.
Conclusion:
in

continuous

alachlor.
types

no-till

This

of weed

Those respondents who had more years

again

and the

corn
may

applied

be

higher

attributed

inability of

to

rates
changes

of
in

alachlor to control

the weeds.

Discussion
This
contrast
the

section

between

findings

of

some

of the

some

other

soil conservation.
studies

did

not

focuses

It
deal

herbicide application.

on

the

findings
similar

comparison
in

the study

studies

related

and
and
to

is worth noting that these other
specifically

with

chemical

or

138

Sources of Information
This study found that the four primary sources of
information for herbicide application by the respondents
were:

container

salespeople,

the

labels,
Soil

chemical

Conservation

Cooperative Extension Service.
traditional

farming

information

relied

on

and

the

is contrary to the

where

personal

fertilizer

Service,

This

communities

and

those

primary

seeking

sources

of

information such as fellow farmers they interact with on
a

face-to-face

respondents

basis

in

this

farmers, friends,
of

information

(Kirkalas,
study,

1983).

19

(or

Of

20.6%)

the

92

indicated

or neighbors as "very important" source

compared

to

61

(or

66.3%)

which

noted

container labels as very important.
The

discrepancy

in

the

sources

of

information

could be explained by the
proliferation of the mass media, the ease of
transportation, and the continuing development of
electronic information generating,
processing,
communicating, and storing systems which has made
rural
residents
more
comfortable
with
the
secondary
impersonal
information
sources
(Bradshaw and Blakely, 1979).
Although the
asked

to

state

information
applied,

respondents

reasons

they

why

they

selected

for

in this
choose
the

study were not
the

sources

herbicides

of

they

one of two information models or both could be

used to explain why one chooses one source of information
over another.

According to Hardy (1982), the first model

139

says

that

provides
The

one

the

second

chooses

will

use

perceived

a

source

highest

model postulates

a

source

of

of

information

quality

of

that

information.

that the information seeker

information

that

minimizes

regardless of the quality of the information.

costs

Birkel and

Repucci (1983) found that accessibility and speed factors
seem

to

be

dominant

information source

influences

on

the

choice

of

rather than the amount of quality of

the information.
Impact of Educational Level
One
respondents
because

would
to

they

have

apply
would

poorer management

expected

more
have

skills,

the

herbicides
less

access

and would

less
than
to

educated

recommended
information,

less understand

the

dangers of herbicide misuse and the potential impacts on
the

environment,

especially

the

groundwater

and

the

was

no

rate

of

surface water.
The

data

statistically
herbicide
more

significant

application

educated

indicated

there

difference

between

respondents

that

in

the

the less educated

where

the

those with high school certificate

less

and the

educated

and less,

while more

educated had more than high school certificate.
contrary,

soil

conservation

studies

by

Ervin

were

and

On the
Ervin

(1982), Pampel and Van Es (1977), and Nowak and Korsching

140

(1981)

and

education

Carlson
has

a

et

al.

positive

(1977,

1981)

influence

on

found

that

conservation

efforts because the more highly educated farmers may have
better access to information and better management skills
(Kerns and Kramer, 1985).
Impact of Tenure
One

would

cultivate to
and

to

expect

be

expect

those

be more judicious

stewards

those

of

who

the

own

who

the

in herbicide

land.

their

own

land

application

Therefore,

land

to

they

one would

apply

herbicide

according to the recommended rates.
This

study

showed

that there was no

significant

differences between those who owned their farm and those
who

rented

in

regard

to

the

amount

Korsching

(1981)

of

herbicides

they

applied.
Nowak

and

found

a

positive

relationship between the degree of ownership and the use
of

less

erosive

(1985)

did

their

study

pollution

practices.

not

find

of

with

any

such

farmers'

regard

to

However,
positive

attitudes
control

and

Kerns

and

Kramer

relationship
toward

in

nonpoint

participation

in

cost-share programs.
Income and Its Impact
One would
herbicides

expect

according

to

the wealthier

farmers

recommended

rates.

to

apply
This

141

assumption

is

based

on

the

fact

that

wealthier

farmers

are more likely to own or rent the most appropriate and
efficient
used
al.

in

farming

tools

and

machinery,

dispensing herbicides

(1981)

found

a

positive

in the

farm.

association

income and conservation practices use.
reported

a

positive

relationship

conservation and farm income.
(1978)

found

a

slightly

especially

those

Carlson et

between

gross

Baron (1981) also

between

investment

in

Similarly, Dillman et al.

higher

gross

income

for

Soil

Conservation Service cooperators than noncooperators.
Contrary
relationship

between

conservation
there

was

middle,

to

practices,

no

studies
higher
this

significant

reporting

income
study

and
found

difference

the

income

the

use

that

overall

among

the

of

lower,

or higher income groups with regard to the rates

of herbicides applied by the farmers.
was

positive

application of alachlor
farmers

herbicides.

apparently

The only exception

in no-till where middle

applied

higher

rates

of

An explanation for the higher alachlor rates

is that mid-income to high-income farmers tend to apply a
fall grass herbicide such as alachlor.
level

of

income

herbicides applied.

had

no

influence

Essentially,
on

the

rates

the
of

142

Impact of Full-time and
Part-time Farm Work
Kerns and Kramer (1985) found that
whether the farmer was a full-time or part-time
farmer did not have a significant impact on the
application for Rural Clean Water Project (RCWP)
funding, a PMP cost-sharing program operated by
the United States Agricultural Stabilization and
Conservation Service (ASCC).
This
the

rate

study

of

found

herbicides

that

in

applied

all

by

cases

the

in no-till,

farmers

did

not

depend on whether the farmer was full time or part time.
Impact of Farm Size
Several
Carlson

et

Earle

et

found

a

studies

al.

al.

including Wagner

(1981),
(1979)

strong

Coughenour

and

Kerns

relationship

and

and

et

al.

(1981),

Kothari

(1981),

Kramer

between

farm

(1985)
size

have

and

the

adoption of conservation practices.
According

to

Wegener

et

al.

(1981)

a

strong

relationship is expected between the size of the farm and
the

use

of

flexibility
farms

in

conservation

expected

their

discretionary
experiment

are

better

the

part

decision-making
resources,

with

scale basis,

on

practices

best

of

because
operators

process,

(3)

more

management

(2)

of
of

large

access

opportunity

practices

(1)

on

a

to
to

small-

and (4) the possibility that large operators
able

to

deal

with

the

risk

and

uncertainty

143

often

associated

with

adopting

new

agricultural

practices.
Contrary to the above-cited studies in regard to
farm size,
size

of

this study found in almost all cases that the

the

farm

has

no

influence

on

the

rates

of

herbicides applied by the farmers.
Considerations for Nonrespondents
Due to the fairly large number of nonrespondents
(and unusable
information
given

responses),

on whether

similar

or

an attempt was made to obtain

or not nonrespondents

different

responses

would have

compared

to

the

findings based on responses offered by the respondents.
The nine research questions in this study and the
summary of the general findings were sent to the District
Conservationists

(DC's)

in

the

nine

counties

The DC's were asked to offer their feedback.

studied.

The essence

of the feedback as stated in the cover letter to the DC's
was

to

ascertain

findings

would

responses

that

whether

have

been

would

or

not

similar

have

been

the
or

responses
different

received

from

and
from
the

nonrespondent group.
with a few exceptions,
the

findings.

For example,

the DC's agreed with all

seven of the DC's

indicated

that their experience with the farmers would support the
findings

that

most

of

the

farmers

applied

herbicides

144

(atrazine,

cyanazine,

and within the

range

DC's

the

felt

that

recommended

rate

metolachlor,

and

of recommended
27%

was

who
not

alachlor)

rates.

applied

below

Two of the

atrazine

above

the

They

felt

the

realistic.

percentage that over applied should have been less.
in

particular

felt

it

should

have

been

in

the

One
5-10%

range.
Three other findings with opposing responses
worthy

of

note.

findings

that

influence

the

All

the

income

DC's

levels

agreed
of

with

the

rates of herbicides

the

farmers

applied.

are

general
did

not

While seven

DC's agreed with the finding which showed mid income no­
till

farmers

income,

no-till

indicating
make

applied

they

more

farmers,
could

any difference.

not

alachlor
two

of

see why

than
the

low

DC's

income

or

high

disagreed

levels

would

Among the seven DC's that agreed,

one noted that "mid-income to high income farmers tend to
always include a fall grass herbicide such as metolachlor
or alachlor."
Overall,
farm
The

did
only

not

this

study

influence

exception

was

the

found
rate

alachlor

that

the

size of

of herbicides
application

in

the

applied.
no-till

where increase in farm size corresponded with increase in
alachlor applied.

The implication is that the larger the

size of the farm, the more the rate of alachlor applied.

145

Three DC's disagreed while six agreed although none gave
an explanation for their views.
Finally,
significant

this

only

higher
in

that

there

the number

was

was

in

alachlor

no

of years

and the rates of herbicides

exception

in

applied.

application

where

rates of application corresponded with more years

continuous

findings.
rates

found

relationship between

continuous no-till
The

study

no-till.

Four

applied

Six

disagreed,

DC's

agreed

with

the

stating essentially that

"drop with increasing

the

number of years of

no-till."
In
responses

conclusion,
were

findings.
disagreement

it

generally

is

noteworthy

in

support

However,

there

which

suggest

were

of

a

that

that

the

the

few

DC's

research

points

of

areas

of

such

disagreement deserve further inquiries or studies.
Limitations and Recommendations for
Future Study
This
till
The

corn
rather

constitute

study

counties
low
a

nonrespondents

concentrated

in Michigan based

response

limitation
may

on the nine primary no­

have

rate

from

since
had

an

the

on the
the

1987

nine

counties

information

impact

on

data.

the

from
data

analysis and conclusion of the study.
Certain factors
response rate.

may have

This includes:

contributed

to the low

146

1.
their

No-till

best

mood

corn

to

farmers

fill

out

may

not

have

questionnaires

been

in

especially

following the flood of 1986 and the drought of 1987.
2.
not

Complete

have

been

list

of no-till

provided

Conservationists.

by

corn

the

farmers

District

may
Soil

This was obvious because while most of

the District Conservationists were ready with their list,
a

few

wrote

farmers

down

they

only

could

the

names

remember

at

of

the

the

no-till

request

corn

of

the

researcher.
3.
This

also

nonvalid
corn.
were

Parts
was

the

obvious

lists

obtained

were

from the responses.

outdated.

Most

of the

responses were farmers who do not plant no-till

A

few of the letters were

unclaimed

farmers

of

due

indicated

to

change

returned

in address.

because they
A

few

other

they have not planted no-till corn in

the past three years.
Some
the

list

desired

of these

and

the

problems,

inclusion

respondent,

are

of

well

such

as outdatedness

someone

other

documented

by

than

of
the

Dillman

(1978).
Recommendations
To
addressed

further
by

this

explore
study,

made for further research:

the

some

of

following

the

questions

suggestions

are

147

1.
time

or

The

again

farmers
after

studied

should

a few years

to

be

studied

see whether

over

or not

their herbicide application remained the same.
2.
many

A similar, more encompassing study,

more

counties

in Michigan

should

including

be undertaken

to

see if the responses and results are different from this
study.
3.
farmers

A similar study emphasizing conventional corn

should

be undertaken

and the

result compared to

this study.
4.
wheat

Other cash crop farmers,

farmers,

should

be

such as soybean and

studied

to

explore

their

herbicide application habits, since such farmers also use
large

amounts

metolachlor,

of

and

herbicides,

such

as

alachlor,

glyphosate which have the potential

of

contaminating surface and groundwater.
5.

A

relationship
counties

study
between

studied

applied

should
the

and

herbicides,

the

be

done

application
presence

look

conditions
or

specifically

to

absence

atrazine

metolachlor, gramoxone super, glyphosate,

for

in

the

of

the

cyanazine,

and alachlor in

their groundwater and surface water systems.
6.
producing
oranges,

Similarly, those farmers who grow other cashagricultural

lettuce,

and

plants,

such

strawberries

as

grapes,

should

apples,

be studied

to

148

explore

if

they

are

applying

herbicides

according

to

recommended rates.
7.
with
the

an

A

similar

emphasis

age of the

herbicides

study

such as this should

on a research question to

farmer has

applied.

Are

be done

find out

any influence on the
younger

farmers,

for

if

rate of
example,

applying more or less herbicides than older farmers?
8.
survey

To

or

improve on the response rate,

a

considered

person-to-person

for

a

similar

a telephone

interview

research,

might

especially

be

if

the

financial resources are available.
9.
or

Studies need to continue to explore if small-

large-scale

farming

could

there

survive with

herbicides,

since

is

wide

scientists,

environmentalists,

concern

and

the

little or
by

farmers,

general

about environmental consequences of herbicides

no

public

and other

pesticides.
10. A similar, but more detailed, study should be
done

to

herbicide
specific
results

compare
for
soil
of

ingredients

specifically

each

formulation

texture

this

and

study.

within

a

recommended

of

compare
This
range

formulation of the herbicide,
and soil texture.

the

herbicide
the

rates
with

results

with

study

set

the

that

considered

of

each
the

active
the

the organic matter content,

149

Generalizabillty of Study
The
till

corn

findings of this
farmers

recommended
are

rates

significant

herbicides
acres

will

local

herbicides

according

to

on container labels and whether there
differences

be

between

educationally

the

and

Educators and students

management,

research

applying

such as whether no­

rates

of

applied to no-till and conventional till corn

beneficial.
and

are

study,

and

for

example,

reference

district

Department

of

such

of

Agriculture

Cooperative

Extension

the

results

for

Federal,

state,

and

as

Agriculture

Departments

in soil conservation

could use

purposes.

agencies,

professionally

the

United

(U.S.D.A.),

and

Natural

Service Agents,

and

States
Michigan

Resources,

the

District

Soil

Conservationists who work directly with the farmers, will
also benefit.
for example,

This

study will benefit these officials,

by allowing them to make better predictions

and projections on herbicide use in farms especially no­
till farms in
In

their counties.

addition

conservationists,
agencies,

the

to

its

federal,

findings

of

use
and

this

by
local

study

educators,
officials
could

elsewhere, both nationally and internationally
author's

native

country

of

Nigeria).

state governments in Nigeria,
organizations

such

as

the

soil

be

and

applied

(as in the

The _federal

and

in addition to multilateral

World

Bank,

encourage

small-

150

scale

farmers

with

"integrated

packages including advice,
inputs

and

government
boost

other

their

It

is

not

Similarly,

large-scale

agricultural

taxes, credit,

development"

improved infrastructure better

assistance.

encourages

rural

the

commercial

production

by

how

much

information

farmers

to

liberalizing

and investment opportunities

known

federal

(Hear,

or

1985).

guidance

the

commercial and peasant farmers obtain in applying inputs,
such as fertilizer and herbicides.
whether
according

the

farmers

apply

to

recommended

It is also not known

agricultural

application

rates

chemicals

on

container

labels.
The

findings

beneficial

to

herbicides.
chemical

this

chemical

For

to

according

find
to

study

companies

example,

companies

herbicides

of

it

would

out

if

would
that

be

be

manufacture

of

interest

farmers

recommended

also

are

rates

on

for

applying
container

labels.
Farmers may benefit from this study.
could

lead

to

more

effective

herbicide

The results

management

on

farms.

The findings could help to reduce and control one

of

major

the

pollution.
cut

farm

costs.

agricultural

sources

of

nonpoint

source

Better herbicide management will also help to
costs
The

by

general

saving

time,

public

may

labor,
also

and

equipment

benefit

because

better management of herbicides and other farm chemicals

151

could lead to a reduction inpotential health costs and
other

costs

resulting

from

surface

and

groundwater

contamination.
Finally,
federal,
States

state,

this
and

Department

Protection

study

local
of

Agency,

will

be

agencies,

such

Agriculture,

the

Michigan

Department

beneficial
as

to

the United

Environmental
of

Agriculture

(MDA), and the Michigan Department of Natural Resources,
as

well

as

county

Conservationists.

extension

agents

and

District

Soil

This study focuses on the most widely

used herbicides in no-till and conventional corn acreages
in

the nine

help

to

studied.

This

information

would

identify where testing of one or more of these

commonly
area)

counties

applied

rather

herbicides

than

herbicides

which

therefore,

not

should

arbitrarily
might

likely

not
to

groundwater or surface water.

occur

(in

choosing

to

be

persist

commonly
or

be

the

study

test
used,
present

for
and
in

APPENDICES

152

APPENDIX A
SAMPLE LETTER TO RESPONDENTS

153

M K I I K . A N M A I I I'M V IK SI I V
III r M l X I M II I SIM M I I I t u r n IK -M IN I
m

i i i i i

iix h

’i k

im iu u iim

H I T I I M 4 N I . • MK l l l l ! I N • « U i< I I I .

.

April 20, 1988
Dear No-till Farmer:
Herbicides and other chemicals have been shown to be extremely Important in
raising crop productivity.
There is concern about proper menagement of
herbicides and other chemicals to minimise and prevent environmental pollution,
especially groundwater and surface water contamination.
Vhile some studies show
that pesticides are leaching into the groundwater, others show that there is no
difference in pesticide leaching between no-tlll and conventionally (clean)
tilled acreages.
I (Ernest) am a graduate student in the above Department and my Interest In soil
and water conservation triggered this study.
Although I am the principal
researcher, others such as Mr. Dwight Qulsenberry of the SOS have been helpful as
well as Interested In my research topic.
The purpose of this study Is to determine the actual rates of herbicides applied
In no-till corn acreage in Michigan andfactors Influencing application rates.
It is hoped that the results from this
effort will enhance proper and costefficient management of herbicides and chemicals for no-till corn producers such
as yourself and other Michigan farmers.
You have been chosen from a random sample of no-tlll corn farmers from nine major
n o - t l l l c o r n c o u n t i e s In Michigan.
You may be assured of complete
confidentiality.
Your name Is not required in your response. An identification
number has been used for mailing purposes so that your name may be checked off
the mailing list when your response Is returned.
A summary of the results of
this study will be sent to you at your request.
For the purposes of this study, no-tlll is where the soil is left undisturbed
prior to planting.
Planting Is completed in a narrow seedbed or slot created bv
a planter or drill.
Weed control Is accomplished primarily with herbicides .".rid
at least 30X of the soil surface is covered by residue after planting.

An y questions you have will be gladly answered. Please call or write if ne ed be.
A collect call will be accepted at my home. The telephone numbers are (31?) 355/2x6 (home) and (51 /) 35i-6967 (ottlce).
Also feel free to contact your Soil
Conservation District Conservationist or your local Agricultural Extension agent
if you have any questions. Kindly return your response In the enclosed, stamped,
self-addressed envelope by May 12. Thank you for your assistance.
Sincerely,

Dwight Qulsenberry
State Agronomist
USDA, East Lansing, Ml
F.N: cld
Enclosure

Ernest Kdukwe
Craduate Student
Department of Resource Development

154

APPENDIX B
QUESTIONNAIRES (1988 AND 1989)

155

1988

Section I:
1.

Have you used herbicides in no-till corn acreage in
the past three growing seasons?
(1)
(2)

2.

Questions Relating to Practice

Yes
No

In addition to no-till, did you raise conventional
till corn?
(1) Yes
(2) No
(If No, please go to Question 4)

3.

How many acres of
(1)
(2)

4.

till

________
________

acres
acres

Yes
No

How long have you
Years

6.

Acres of No-till
Acres of Conventional

Is your no-till corn acreage in one contiguous area
(that is, in one uninterrupted area?)
(1)
(2)

5.

corn did you plant in 1987?

________________

How long have you
Years

had continuous no-till corn?
(please specify)

planted no-till corn?

________________

(please specify)

156

157

Select a typical no-tlll corn field on your farm
and answer the following questions:
7.1

For each method of application, please list the
name(s) of the herbicide(s), the formulations, and
the rate of application that you applied to this
field in 1987.
a
K
Herbicide Formulation
Rate
Preemergence

_________

____________

___________

Postemergence

Wettable Powder (80W), Liquid (4L), Dry Flowable
(DF) etc.
.Amount of formulated herbicide per acre
(quarts/acre, pounds/acre, etc.)
7.2

in this same field, if you had used conventional
tillage, what herbicides, formulations, and rates
would you have selected?

Preplant
Incorporated

Herbicide

Formulation3

_________
_________

____________
____________

Rate*3
__________
__________

Preemergence

Postemergence

Wettable Powder (80W), Liquid (4L), Dry Flowable
(DF) etc.
^Amount of formulated herbicide per acre
(quarts/acre, pounds/acre, etc.)

158

8.

In what year was the last soil test conducted on
your no-till corn acreage?
(please indicate)

9.

What is the soil pH in the field?
(please indicate)

10.

Which of the following best describes the most
common soil texture in this field?
(Please circle one)
(1)
(2)
(3)
(4)
(5)
(6)
(7)

11.1

‘
11.2

Have you had your soil organic matter level tested
for this field?
(1)
(2)

Yes
NO

What do you think is the organic matter content in
this no-till field?
(1)
(2)
(3)
(4)
(5)
(6)
(7)

12.

Clay
Clay loam
Loam
Sandy loam
Loamy sand
Sand
Muck

< 1/2%
1/2 - 1%
2%
3%
4%
5%
Over 5%

What is the average percent slope of this (no till
field?
(please indicate)

13.

Do you own or rent your no-till acres?
(Please circle one)
(1)
(2)
(3)

Own
Rent
Both

159

Institutional Questions
14.

How often do you visit with your Cooperative
Extension or Soil Conservation Personnel in the
Average month?
(Please circle one)
(1)
(2)
(3)
(4)
(5)

15.

times
times
times
times
10 times

How often do you have telephone consultations with
your Cooperative Extension or Soil Conservation
Service Personnel in the average month?
(Please circle one)
(1)
(2)
(3)
(4)
(5)

16.

< 2
2-4
5-7
8-10
Over

<2
2-4
5-7
8-10
Over

times
times
times
times
10 times

Rate with an X the importance of the following in
terms of your sources of information for herbicide
or chemical application.
V = Very Important;
M = Moderately Important; S « Some Importance;
N = Not Important
V
M
S
N
(a) Soil Conservation Service ______________________
(b) Cooperative Extension
Service _____ ________ ___________________________
(c) Soil Conservation District
Directors
________________________ ________
(d) Container Laoexs _______________________________
(e) Farmers, Friends, Relatives,
or Neighbors
_____________________________
(f) Chemical and Fertilizer
Sales People
' ______________________________
(g) Farm magazines and newspapers
(h) Equipment Company
Representatives _______________________________
(i) Radio or television programs
(j) Local newspaper(s) _____________________________

160

Environmental/Attitudinal Questions
17.

There is an on-going debate that more herbicides
are applied in no-till compared to conventional
tillage.
Do you believe that more herbicides are
applied in no-till than in conventional tillage?
(1)
(2)

18.

From your experience, do you think that you apply
the same rates of herbicide to the same acreages
each year?
(1)
(2)

19.

Yes
No

Yes
No

Rate with an X the following in order of importance
as reason(s) for the amount of herbicides you
applied in your no-till corn.
V = Very Important;
M = Moderately Important; S = Some Importance;
N - Not Important
V
M
S
N
(1) Desire to increase crop
Production
•
(2) Desire to increase farm
profitability
•
(3) Type of weed on your
corn acreage
•
(4) Advice from local Soil
Conservation District
•
(5) Advice from local Cooperative
Extension Agent
•
(6) Advice from Chemical and
Fertilizer sales aoents
•
(7) Personal Farming habits
•
(8) Other
(Please specify)

161

20.

21.1

Rate with an X the following in terms of factors
that would cause you to use less herbicide than you
used in 1987.
V
M
S
N
(1) Higher cost of herbicides
this year
______
(2) Personal concern about
potential injury from
herbicide application _________________________ L
(3) Concern for surface and
groundwater
(4) Concern for potential
rule violation ___i^_____________________________ ._
(5) Advice from chemical
salesperson
(6) Advice from a fellow
farmer
Studies have shown that there is concern about
potential health risks to farm families, neighbors,
and others resulting from agricultural chemicals,
pesticides, and fertilizers.
In terms of your own
family and neighborhood, do you think such concerns
are justified?
(1) Yes
(2) No
(If No, please go to Question 22.1)

21.2

If such concerns are justified, how would you rank
the concern?
(Please circle one)
(1 )
(2)
(3)
(4)

22.1

very concerned
Moderately concerned
Some concern
Not concerned

Some studies have indicated that agricultural
practices are significant sources of environmental
pollution relative to other sources of pollution
such as industries.
Do you think that agricultural
practices are significant source of environmental
pollution in your county?
(1) Yes
(2) No
(If No, please go to Question 23)

L

162

22.2

How significant do you think environmental
pollution from agricultural practices is in your
county?
(1)
(2)
(3)
(4)

23.

Recent studies in Michigan has shown that
groundwater and surface water contamination could
be a serious issue in some parts of the state.
From your point of view, how serious do you think
the issue of groundwater and surface water
contamination are in your county?
(1)
(2)
(3)
(4)

24.

Very serious
Moderately serious
Somewhat serious
Not serious

Some wells in Michigan have been contaminated by
agricultural chemicals, such as nitrates.
From
your experience, how much of a problem do you think
contamination of wells pose in your county?
(1)
(2)
(3)
(4)

25.

Very significant
Moderately significant
Some significance
Not significant

Very serious problem
Moderately serious
Somewhat serious
Not serious

To what extent do you think well contamination in
your county is caused by herbicides?
(1)
(2)
(3)
(4)

A large extent
Moderate extent
Some extent
None

163

Demographic Questions
26.

Which of the following represents your highest
level of education?
(Please check one ) .
(1)
(2)
(3)
(4)
(5)
(6)
(7)

27.

Less than high school
High school graduate
2-Year vocational education degree
Some undergraduate college education
Undergraduate college degree
Some graduate studies
Graduate degree

Are you a full-time farmer?
(1) Yes
(2) No
(If No, go to Question 29 below)

Definition:

28.

If yes (full-time farmer), which of the following
categories represent your after-taxes annual farm
income?
(Please check one)
(1)
(2)
(3)
(4)
(5)
(6)
(7)
(8)

29.

Full-time farmers are those who spend 100%
of their time working on their farm and who
derive all their income from the farm.

Less thani $10,000
10,001 - 14,999
15,000 - 24,000
25,000 - 34,999
35,000 - 43,999
44,000 - 49,999
50,000 - 59,999
Above 60, 000

What percentage of your combined annual income is
derived from the farm?
(1)
(2)
(3)
(4)
(5)
(6)
(7)
(8)
(8)

Less than 10%
10% - 19%
20% - 29%
30% - 39%
40% - 49%
50% - 59%
60% - 69%
70% - 80%
80% and above

Thank you!
Your cooperation is very much appreciated.
Please return by May 12, 1988.
Once gain, your
name is not required on the form.

1989
Section 1:

Questions Relating to Practice

Have you used herbicides in no-till corn acreage in
the past three growing seasons?
(1)
(2)

Yes
No

In addition to no-till, did you raise conventional
till corn?
(1) Yes
(2) No
(If No, please go to Question 4)
How many acres of corn did you plant in 1988?
(1)
(2)

Acres of No-till
acres
Acres of Conventional till _____ acres

Did you plant the same number of corn acreage in
1988?
(1)
(2)

Yes
No

If No, how many acres of corn did you plant in
1988?
(1)
(2)

Acres of No-till
acres
Acres of Conventional till ____ acres

Is your no-till corn acreage in one continuous area
(that is, in one uninterrupted area)?
(1)
(2)

Yes
No

How long have you had continuous no-till corn?
______________________ years (please specify)
How long have you planted no-till corn?
______________________ years (please specify)

165

Select a typical no-till corn field on your farm
and answer the following questions:
7.1

For each method of application, please list the
name(s) of the herbicide(s), the formulations, and
the rate of application that you applied to this
field in 1987.
a
k
Herbicide Formulation
Rate
Preemergence

_________

____________

___________

Postemergence

Wettable Powder (80W), Liquid (4L), Dry Flowable
(DF) etc.
.Amount of formulated herbicide per acre
(quarts/acre, pounds/acre, etc.)
7.2

In this same field, if you had used conventional
tillage, what herbicides, formulations, and rates
would you have selected?

Preplant
Incorporated

Herbicide

Formulation3

_________
_________

____________
____________

Rate*3
__________
__________

Preemergence

Postemergence

Wettable Powder (80W), Liquid (4L), Dry Flowable
(DF) etc.
^Amount of formulated herbicide per acre
(quarts/acre, pounds/acre, etc.)

166

8.

In what year was the last soil test conducted on
your no-till corn acreage?
____________________________

9.

What is the soil pH in the field?
____________________________

10.

Yes
No

What do you think, is the organic matter content in
this no-till field?
(1)

< 1/2%

(2 )
(3)
(4)
(5)

1/2 - 1%
2%
3%
4%

§ tr

12.

Clay
Clay loam
Loam
Sandy loam
Loamy sand
Sand
Muck

Have you had your soil organic matter level tested
for this field?
(1)
(2)

11.2

\

r~ <■*

V V )

3t>

(7)

Over 5%

What is the average percent slope of this (no till)
field?
____________________________

13.

(please indicate)

Which of the following best describes the most
common soil texture in this field?
(Please circle one)
(1)
(2)
(3)
(4)
(5)
(6)
(7)

11.1

(please indicate)

(please indicate)

Do you own or rent your no-till acres?
(Please circle one)
(1)
(2)
(3)

Own
Rent
Both

167

Institutional Questions
14.

How often do you visit with your Cooperative
Extension or Soil Conservation Personnel in the
Average month?
(Please circle one)
(1)
(2)
(3)
(4)
(5)

15.

times
times
times
times
10 times

How often do you have telephone consultations with
your Cooperative Extension or Soil Conservation
Service Personnel in the average month?
(Please circle one)
(1)
(2)
(3)
(4)
(5)

16.

<2
2-4
5-7
8-10
Over

<2
2-4
5-7
8-10
Over

times
times
times
times
10 times

Rate with an X the importance of the following in
terms of your sources of information for herbicide
or chemical application.
V = Very Important;
M = Moderately Important; S = Some Importance;
N = Not Important
V
M
S
N
(a) Soil Conservation Service ______________________
(b) Cooperative Extension
Service ______
_ _ ______________________
(c) Soil Conservation District
Directors
(u) Container LaDeis _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _
(e) Farmers, Friends, Relatives,
or Neighbors
_____________________________
(f) Chemical and Fertilizer
Sales People _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _
(g ) Farm magazines and newspapers
(h) Equipment Company
Representatives
(i) Radio or television programs
(j ) Local newspaper(s) _____________________________

168

Environmental/Attltudlnal Questions
17.

There Is an on-going debate that more herbicides
are applied in no-till compared to conventional
tillage.
Do you believe that more herbicides are
applied in no-till than in conventional tillage?
(1)
(2)

18.

From you experience, do you think that you apply
the same rates of herbicide to the same acreages
each year?
(1)
(2)

19.

Yes
No

Yes
No

Rate'with an X the following in order of importance
as reason(s) for the amount of herbicides you
applied in your no-till corn. V = Very Important;
M = Moderately Important; S = Some Importance;
N = Not Important
V
M
S
N
(1) Desire to increase crop
Production
______ _____________________________
(2) Desire to increase farm
profitability __________________________________
(3) Type of weed on your
corn acreage
________________________________
(4) Advice from local Soil
Conservation District
______________________
(5) Advice from local Cooperative
Extension Agent
(6) Advice from Chemical and
Fertilizer sales agents
(7) Personal Farming habits ________ ____________
(8) Other ___________________________ (Please specify)

169

20.

Rate with an X the following in terms of factors
that would cause you to use less herbicide than you
used in 1988.

v

M

s

N

(1) Higher cost of herbicides
(2) Personal concern about
potential injury from
herbicide application
(3) Concern for surface and
groundwater
(4) Concern for potential
rule violation
(5) Advice from chemical
salesperson
(6) Advice from a fellow
farmer
21.1

•

Studies have shown that there is concern about
potential health risks to farm families, neighbors,
and others resulting from agricultural chemicals,
pesticides, and fertilizers,
in terms of your own
family and neighborhood, do you think such concerns
are justified?
(1) Yes
(2) No
(If No, please go to Question 22.1)

21.2

If such concerns are justified, how would you rank
the concern?
(Please circle one)
(1)
(2)
(3)
(4)

22.1

very concerned
Moderately concerned
Some concern
Not concerned

Some studies have indicated that agricultural
practices are significant sources of environmental
pollution relative to other sources of pollution
such as industries.
Do you think that agricultural
practices are significant sources of environmental
pollution in your county?
(1) Yes
(2) No
(If No, please go to Question 23)

170

22.2

How significant do you think environmental
pollution from agricultural practices is in your
county?
(1)
(2)
(3)
(4)

23.

Recent studies in Michigan has shown that
groundwater and surface water contamination could
be a serious issue in some parts of the state.
Prom your point of view, how serious do you think
the issue of groundwater and surface water
contamination are in your county?
(1)
(2)
(3)
(4)

24.

Very serious
Moderately serious
Somewhat serious
Not serious

Some wells in Michigan have been contaminated by
agricultural chemicals, such as nitrates.
From
your experience, how much of a problem do you think
contamination of wells pose in your county?
(1)
(2)
(3)
(4)

25.

Very significant
Moderately significant
Some significance
Not significant

Very serious problem
Moderately serious
Somewhat serious
Not serious

To what extent do you think well contamination in
your county is caused by herbicides?
(1)
(2)
(3)
(4)

A large extent
Moderate extent
Some extent
None

171

Demographic Questions
26.

Which of the following represents your highest
level of education?
(Please check one).
(1)
(2)
(3)
(4)
(5)
(6)
(7)

27.

Less than high school
High school graduate
2-Year vocational education degree
Some undergraduate college education
Undergraduate college degree
Some graduate studies
Graduate degree

Are you a full-time farmer?
(1) Yes
(2) No
(If No, go to Question 29 below)

Definition:

28.

If yes (full-time farmer), which of the following
categories represent your after-taxes annual farm
income?
(Please check one)
(1)
(2)
(3)
(4)
(5)
(6)
(7)
(8)

29.

Full-time farmers are those who spend 100%
of their time working on their farm and who
derive all their income from the farm.

Less than $10,000
10,001 - 14,999
15,000 - 24,000
25,000 - 34,999
35,000 - 43,999
44,000 - 49,999
50,000 - 59,999
Above 60 ,000

What percentage of your combined annual income is
derived from the farm?
(1)
(2)
(3)
(4)
(5)
(6)
(7)
(8)
(8)

Less than 10%
10% - 19%
20% - 29%
30% - 39%
40% - 49%
50% - 59%
60% - 69%
70% - 80%
80% and above

Thank y o u ! Your cooperation is very much appreciated.
Please return by May 12, 1988.
Once gain, your
name is not required on the form.

172

M I C H I G A N S T A T li U N I V E R S I T Y
DEPARTM ENT O F RESOURCE DEVELOPMENT

EAST LAN 'SIN G • M IC H IG A N • <1124 1222

NATURAL RESOURCES BUILDING

March 1 4 ,

1989

D ea r N o - T i l l F a r m e r :

About a month ago, a questionnaire seeking your response on the actual rates of
herbicides you apply in your no-till corn acreage vas mailed to you.
Please accept my sincere thanks if you have already completed and returned your
response. If not, please do so today. It is extremely important that your
response be included in the study if the results are to be accurately
represented.
If by some chance you did not receive the questionnaire, or if it got misplaced,
please call me right now, collect (517/355-4047) and I will send another one in
the mail to you today.
Sincerely,

Ernest Ndukwe
Graduate Student
Department of Resource Development

TELEX: 1S6IM. RDCR UR
IIU/ fian A({xrm*U\'t

lnUii*tn>n

APPENDIX C
FURTHER DISCUSSION OF THE KEY PHYSICAL
AND CHEMICAL CHARACTERISTICS OF
PESTICIDE LEACHERS

173

Canter
key

et

physical

leachers,

as

al. (1987)

and chemical
well

as

the

descriptively

outlined

the

characteristics of

pesticide

key

affecting

soil

pesticide transport to groundwater.

factors

The key physical and

chemical characteristics are:
1.
for

Water Solubility:

a pesticide

to

Defined

dissolve

in water.

water solubility of the pesticide,
carried

in

solution

to

as the propensity
The

higher

the

the greater the amount

groundwater.

Water

solubility

greater than 30 ppm has been identified as a "flag" for a
possible pesticide "leacher."
2.

Soil

pesticide

to

ratio

the

of

Adsorption:

"stick"

to

The

soil

pesticide

propensity

particles

defined

concentration

in

soil

of

a

as

the

to

the

pesticide concentration in water.
3.
disperse
the

Volatility:

into

vapor

the

air.

pressures

of

The propensity for a pesticide tc
This

is primarily a function of

the

chemical

and

is

strongly

influenced by climatic and environmental factors, such as
temperature and wind speed.
4.
persistence

Soil Dissipation:
of

a pesticide

This

in the

is

a measure

soil.

It

of the

is usually

measured as the length of time required for dissipation of
one-half the concentration of a pesticide.
174

175

Soil dissipation depends on several environmental
processes,

such

as

vaporization,

decomposition processes,

sucn

and microbial transformation.

as

well

as

on

as hydrolysis,

several

photolysis,

Hydrolysis is the reaction

of a chemical with water while photolysis is the breakdown
of a chemical

from exposure to sun's energy.

transformations

occur

from

the

metabolic

Microbial

activities

of

mircro organisms within the soil.
Bailey
processes

et

believed

pesticides.

to

They

degradation,

is

condition
metabolized,

are

(1985)
influence
microbial

similarly
the

An
organism

where

the

degraded,

additional
uptake.

rate

of

four

decay

of

chemical

degradation,
process
It

pesticide
and

noted

degradation,

photochemical

volatilization.
processes

al.

excreted

is

the

defined

may
by

to

and

be
both

four
as

a

taken

up,

target

and

nontarget organisms.
The key soil factors affecting pesticide transport
to groundwater as outlined by Canter et al.
1.

Clay Content:

clay minerals.

(1987) are:

This refers to the presence of

Clay minerals are important because they

contribute to cation exchange capacity or the ability of
the soil to adsorb positively charged molecules (cations).
The positively charged pesticides are, therefore, adsorbed
to soil containing negatively charged clay particles.

The

176

fact

that

clay

soils

have

a high

surface

area

further

contributes to adsorption capacity.
2.
OMC

Organic Matter Content (OMC):

adsorb

pesticides

and,

therefore,

movement into groundwater.
highly

adsorbed

to

higher

rates

farmers

portion.

by

Some

of

However,

organic
to

soil

inhibit

are

later

pesticide

pesticides which are
often

compensate

these may

Soils with high

be

for

applied

at

the

adsorbed

released

into the

groundwater.

Overall, OMC is important because it affects

bioactivity,

bioaccumulation,

biodegradability,

leach-

ability, and volatility of pesticides.
3.
sand,

Soil Texture:

silt,

and

clay.

Texture refers

Leaching

occurs

to the percent
more

rapidly

in

coarse or light-textured sandy soils than in fine or heavy
textured clayed soils.
4.

Soil Structure:

Structure is important and it

refers to how soil grains are grouped together into large
aggregates, such as nlaty, prismatic, blccky, or granular.
Structure

is

affected

by

texture

and

organic

matter

content.
5.
space,

pore

Porosity:
size,

and

This
pore

is a function of
size

total

distribution.

pore

It

is

determined by soil texture, structure, and particle shape.
Pesticide transport is more rapid through porous soils.
6.

Soil

Moisture:

Refers

to

the

presence

of

water in the soil which is important because it ultimately

177

transports pesticides that are not adsorbed into the water
table

below.

Capillary

movement of water.

action

can

bring

about

upward

In addition, upward movement of water

can result from evapotranspiration in which water in the
soil is lost to the air.
7.

Depth

pesticide

to

must

groundwater

is

Groundwater:

travel
a

through

vital

factor

The
the

in

distance

soil

to

determining

a

reach
whether

contamination will occur at a particular site.
In

addition

characteristics

of

to

the

key

physical

pesticide

leachers

pesticide

transport

and

and

chemical

the

key

soil

factors

affecting

Canter

et al.

methods

and conditions that affect pesticide transport to

groundwater.
1.
pesticide

(1987)

the

noted

the

groundwater,

key

application

The methods and conditions are:
Local

Climatic

leaching

amount of local
of

also

to

soil

at

a particular

rainfall.

and

Conditions:

The

site

depends

Additionally,

surrounding

air

at

degree
on

of
the

the temperature
a

site

affects

-pesticides' transport and degradation.
2.
groundwater

Rate

of

Application:

contamination

is

how

A

critical

much

and

factor

how

in

often

a

pesticide is applied to the soil.
3.

Timing

environmental

of

Application:

conditions,

temperature

Depending
and

time of application of a pesticide matters.

on

local

rainfall,

the

178

4.
topsoil

Method

of

Application:

application

formulations),
chemigation
injection
pose

soil

are

and

(granular,
injection,

forms

of

greatest

contamination.

soil

are

Chemigation,

spraying,
or

liquid

incorporation
application.

generally

likelihood

and
Soil

considered

for

to

groundwater

which is the application of

pesticides

through irrigation,

source

groundwater

of

dust,

pesticide

incorporation

the

Aerial

can also be a significant

contamination,

especially

when

an

irrigation pump shuts down due to mechanical or electrical
failure while the pesticide-adding equipment continues to
operate.

Such

pesticides

into

a

malfunction

the

well

or

can

cause

cause

a

highly

backflow

of

concentrated

pesticide levels to be applied to a field.
5.
increase
soil,

Irrigation

the soil

raising

However,

Practices;

moisture content

the

potential

irrigation

can

These
and

for

flow

through the

chemical

decrease

volatilization of some pesticides

practices

the

leaching.
amount

from the soil.

of

Excess

irrigation can carry pesticides down the well casings
abandoned or poorly constructed wells,
contaminants into the aquifer.
can

also

lead

to

direct

of

directly injecting

The use of drainage tiles
input

of

pesticides

into

groundwater regardless of their leaching potential.
6.
and

no-till

Cultivation
practices

Practices:
which

Conservation

curtail

soil

tillage

erosion

and

179

pollutant runoff into streams increases water infiltration
and hence the potential
groundwater.

for pesticides leaching into the

In addition,

conservation practices require

increased herbicide use which may leach.
7.

Spillage/Disposal;

groundwater

contamination

can

result

A

high

from

potential

spillage

disposal due to high concentrations of pesticides
soil

which

can

overwhelm

normal

decomposition

for

and

in the

processes

and soil adsorption capacity.
Spillage can be a common problem where pesticide
mixing

and

loading

occurs.

In

addition,

handling

of

unwanted pesticides and empty containers, as well as rinse
water from the cleaning of spray equipment may also pose
problems

which

can

lead

to

leaching

and

eventual

contamination of groundwater.
Formulations of Herbicides
How a herbicide performs depends

a great deal on

the formulation in addition to other factors, auoh as clay
content,

organic matter content,

texture,

porosity,

rate

of application, and timing of application.
There

are

two

closely-related

The

formulation

definitions

of

formulation:
1.
condition

in

which

1983).

Similarly,

a

herbicide
it

is

is

is
sold

defined

the
for

as

a

final

use

(Ware,

herbicide

physical

180

preparation
use.

It

supplied

by

the

(the formulation)

manufacturer

for

practical

includes the active ingredient

(actual toxicant) and inert ingredients, such as solvents,
diluents, and various adjurants (Ross and Lembi, 1985).
2.

Formulation is also defined as the process the

manufacturer
practical
process,

undergoes

use

(Ross

in

and

preparing

Lembi,

herbicides

1985).

for

Through

the

the user is presented with a herbicide in a form

that handles conveniently.
Matthews
apesticide
than

are often dictated

by

cost

criteria

rather

whether the active ingredient will be more effective.

Furthermore,
been

(1979) stated that methods of formulating

it was

marketed,

as

indicated

wettable

that many

powders,

pesticides

owing

both

to

have
high

cost of suitable solvents for the active ingredient and to
the cheaper handling costs of powders.
Major Types of Herbicide Formulations
Most
formulations.
SL),

water

concentrates
dispersible

of

the

They
soluble

herbicides

include water
powders

used

are

soluble liquids

(WSP),

water

(E or EC), wettable powders
granules

(WDG

liquids (WDL, L, or F ) .

or

DF)

sprayable

and

(S or

emulsifiable

(W or WP), water

water

dispersible

181

Granules and pellets are dry formulations used for
direct application.

They comprise a smaller proportion of

herbicide formulations used.
Characteristics of the Formulations
Water Soluble Liquids (WSL)
These
agitation

mix

and

dissolved.

completely

require

They

no

require

in

water

additional
wetting

with

minimum

agitation

agents

for

once

maximum

activity and most of the formulations contain 2 to 4 lb.
of active ingredient.
Water Soluble Powders (SP)
These are dry, finely divided solids that dissolve
completely

in

indefinitely

water.

and

do

They

not

form

remain

as

solutions

precipitates.

Typical

formulations contain 40 to 90% active ingredient.
Wettable Powders (W or WPL)
These are essentially concentrated dusts or finely
ground solids containing a wetting agent to facilitate the
mixing

of

the

powder

with

water

before

spraying.

The

wetting agent prevents the powder from floating when added
to

water.

treatments,

Most

wettable

although

powders

are

used

as

soil

sometimes they are used on foliage.

The formulations normally contain 50 to 80 percent active
ingredient.

182

Water Dispersible Liquids
(WDL, L, or F)
These herbicides frequently designated as liquids
or

flowables,

liquid

are

system.

wettable

finely

The particles

powders.

formulations

ground

Some

commonly

solids

suspended

are smaller

agitation

contain

is

4

in

a

than those of

required.

pounds

of

The
active

ingredient per gallon.
Emulslflable Concentrates
(E or EC)
These
emulsifiers.
oil

oily

(nonpolar)

liquids

containing

They disperse in water to form droplets of

surrounded

agitation.

are

by

water

(emulsions).

They

require

some

Most of the formulations contain 2 to 6 lbs.

of active ingredient per gallon.

They are soluble in oil.

Water Dispersible Granules
(WPG or DF)
These

are

also

soluble granules.

called

dry

flowables

and

water

They are dry formulations of granular

dimensions made up of finely ground solids combined with
suspending and dispersing agents.
dispersible
disperse
container.

liquids

without

and

They handle better than

wettable

clumping

and

powders

pour

because

cleanly

from

they
the

183

Granules (G)
Granules are applied directly from the package to
the

field

utilized
starch

without
as

granule

polymers,

residues.
than

dilution.

10mm

Dry

components

dry

substances

including

fertilizers,

have

clay

and

been

minerals,

ground

plant

Granules are discrete particles generally less
3
in size.
They have an advantage
over

driftable dry formulations or dusts and also have smaller
rate
more

of volatilization.
rainfall

to

formulations do.
the 1950s,
no

leach

into

is required,
method

drawback)

has been

has

its

soil than

products

slow.

attributed

required

reluctant

slightly
sprayable

for

granule

the

that

application

with

herbicide

slowness

is

(or
the
more

with a smaller

in granules,

machine

a

fact

Additionally,

available

to purchase a

This

to

in

advantage that

acceptance as

been

specialized than a sprayer.
of

the

require

Granules were first used in the U.S.

application

range

they

but in spite of the tremendous

mixing

equipment

However,

farmers

limited

are

use

(Matthews, 1979).
Pellets (P)
These

are dry

formulations

in discrete particles

that are usually larger than 10 m m 3 .

They are frequently

used

their

for spot

applications

and

concentrations typically range from 5 to 20%.

herbicide

184

Choice of Formulations
Ware

(1983)

noted

that

the

pesticide

is acceptance by the user.

pesticide

must

be

effective,

safe,

real

test

for

a

To be accepted,
easy

to

apply,

a

and

relatively economic.
Matthews

(1979)

usually been selected
user.

stated

that

formulations

have

on the basis of convenience to the

For example, farmers who have l.vge tractor-mounted

sprayers

fitted

emulsifiable
into the

with

hydraulic

concentrates

which

tank from the can,

agitation

can

be

poured

prefer
straight

particularly as a volume of

concentrate is much easier to measure than to weigh out a
powder.
In

many

parts

of

the

world,

the

less

expensive

wettable powder used as prepackaged selected weights has
reduced

the

(Matthews,

problem
1979). *

of
In

weighing

powders

developing

on

countries,

the

farm

choice

of

formulation has often been dictated by the availability of
equipment.

For example, in the absence of a sprayer, low-

percentage-concentration dusts
applied.

and granules

can be hand-

However, where labor or specialized equipment is

absent, farmers may be reluctant to use granules,
areas,

scarcity

granules,

of water

although

high

dictated
costs

the use

of

in many

of dusts

transportation

and
have

favored the use of highly concentrated formulations since
they are less bulky (Matthews, 1979).

185

Since
susceptible

some

to

plants

certain

and

individual

solvents

and

varieties

other

are

ingredients,

choice of formulation may be determined by phototoxicity.
Phototoxic effects may be caused by chemical burning or by
subsequent
Finally,

effects

Matthews

formulation

on

plant

(1979)

is decided

growth

concluded

by what

is

(Matthews,

that

the

readily

1979).

choice

available

of
and

the price.
Herbicide Classification and
Mode of Action
There

are

several

ways

to

classify

herbicides.

Ross and Lembi (1985) identified eight classifications and
declared

that

herbicide

categorization

is

a

matter

of

convenience based largely on those aspects the describer
wants to emphasize.

(1985)

Five classifications

adapted

of

be

herbicides

will

from Ross

addressed.

and Lembi
These

are

classifications based on?
1.

Degree

of

response

species.

In this category,

selective

and

nonselective.

chemical that is more
others.

differences

among

plant

a herbicide is classified as
A selective

herbicide

is a

toxic to some plant species than to

Nonselective herbicides are toxic to all species

present.
2.

Classification

Target A r e a .

based

on

the

Coverage

of

the

This category refers to broadcast treatment,

186

band treatment,
comprise

of

and spot treatment.

application

over

the

Broadcast treatments
entire

field

or

area.

Band treatments describe a somewhat restricted application
such

as

on

a

row rather

than the

entire

field.

treatment refers to application to localized

Spot

areas,

such

as on individual plants or weeds.
3.
Weed

Germination

categories
and

Classification Based

in

and

in Relation to Crop and

Development;

Three

this category are preplant,

post-emergence

herbicides.

Preplant

important

pre-emergence,
herbicides

are

applied to the soil surface before the seeds are planted.
Pre-emergence herbicides are applied before the crop or a
particular
applied

weed

after

emerges.

Post-emergence

the emergence

of

the

Based

on

herbicides

crop or

are

a specific

weed.
4.

Classification

Application:
surface

Methods

of

Soil

In this category are herbicides that may be

applied,

incorporated

(or

mixed

into

the

soil)

layered, or injected.
5.

Classification Based on Herbicide Movement on

or in Plants.
their

movement

Herbicides can also be grouped according to
on

or

in

the

plant.

This

category

includes:
a.

Herbicides that show little or no movement in
the

plant.

herbicides

These
when

are

applied

known
to

as

contact

foliage.

An

187

example

Is paraquat

which kills

the

part

of

the plant it encounters.
b.

Apoplastic (xylem) only movement which move in
the

system of

the plant

that

conducts

water

and nutrients
c.

Symplastic
in

the

(phloem) only movement which moves

symplast

with

the

sugars

into

the

points of active growth or food storage.
Matthews

(1979)

suggested

that

"grouping

of

pesticides according to their mode of action is sometimes
of more practical

importance than a classification based

on chemical structure, since it may affect selection of an
application technique."
For a herbicide,

the mode of action refers to how

the herbicide affects a plant or how it does what it d o e s .
Ross

and

including

Lembi
auxin

(1985)
type

identified

growth

seven

regulators,

categories,

photosynthetic

inhibitors

(where the chloroplast is the site of action),

disruption

of

seedling

root

cell
or

permeability,
shoot

disruptors

inhibitors,

inhibitors, and pigment inhibitors.

of mitosis,

general

metabolic

BIBLIOGRAPHY

188

BIBLIOGRAPHY

Ahrens, C., and Cramer, H. H.
(1985).
"Improvement of
Agricultural Production by Pesticides."
In
Environment and Chemicals in Agriculture. Edited by
F. P. W. Winteringham.
New York:
Elsevier Applied
Science Publishers, p. 151.
Allen, D.; Sommers, C. E.; and Trevis, C.
(1986).
"A
Picture of Pesticide Exposure."
Successful Farming
84(10) .
Bailey, George; Mulkey, L. A.; and Swank, Jr., R. R.
(1985).
"Environmental Implications of Conservation
Tillage: A Systems Approach."
In A Systems
Approach to Conservation Tillage. Edited by Frank
M. D'Itri.
Lewis Publishers, pp. 239-265.
Bailey, G. W . , Swank, R. R. Jr.; and Nicholson, H. P.
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