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THESlS

This is to certify that the

thesis entitled

ENERGY AND LABOR FLOWS ON AN ORGANIC
AND AN AVERAGE CONVENTIONAL FARMING SYSTEM:
A CASE STUDY ANALYSIS OF RELATIVE SUSTAINABILITY

presented by
Robert Hilliard Pigg

has been accepted towards fulfillment
of the requirements for

Master of Sc1ence degree in Resource Development

 

 

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Date March 23, 1994

 

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ENERGY AND LABOR FLOWS ON AN ORGANIC
AND AN AVERAGE CONVENTIONAL FARMING SYSTEM:
A CASE STUDY ANALYSIS OF RELATIVE SUSTAINABILITY
By

Robert Willard Pigg

A THESIS
Submitted to
Michigan State University

in partial fulfillment of the requirements
for the degree of

MASTER OF SCIENCE

Department of Resource Development

1 994

ABSTRACT
ENERGY AND LABOR FLOWS ON AN ORGANIC
AND AN AVERAGE CONVENTIONAL FARMING SYSTEM:
A CASE STUDY ANALYSIS OF RELATIVE SUSTAINABILITY
By

Robert Willard Pigg

An organic dairy farm in Ingham County, Michigan was compared to a conventional
farming system based on conventional dairy farms in Ingham County, state and county crop and
milk yields, and farm labor budgets from several sources. The two farming systems were
compared on the basis of crop yields per unit of land and labor, milk yields per cow, and energy
outputs per unit of energy input.

The organic'crop yields were lower than state and county averages. Milk yields from the
organic farm were comparable to state averages. Crop rotations on the organic farm produced
more energy per unit Of energy input than did the conventional systems. Unlike a number Of
other studies, this study showed that energy output from the organic farm per unit of labor input
was greater than or equal to the corresponding values from the Michigan conventional examples

for several crops.

This thesis is dedicated to my wife Susan, whose love, support, and encouragement helped make

this thesis possible.

iii

ACKNOWLEDGMENTS

I would like to acknowledge gratefully the assistance and support Of a great many people. I
would like to thank my advisor Tom Edens for his patience, ideas, and his timely reSponses;
committee members George Axinn and Richard Harwood, for their suggestions and insight; Jack
Knoreck of the Cooperative Extension Service for his help with the conventional farming
system; Bob Hicks Of the Ingham County Soil Conservation Service who also helped with the
conventional farming system, and who reminded me that despite the customary terminology, no
farmer who is making a living in today's business climate can really be considered
"conventional;" several area farmers I spoke with; and of course the organic farmer who

generously donated so much of his time to help me with this study. Thank you all.

TABLE OF CONTENTS

LIST OF TABLES ........................................ ix
LIST OF FIGURES ......................................... x
CHAPTER ONE
INTRODUCTION ......................................... 1
Agroecosystems Defined .................................. 2
Open and Closed Agroecosystems ............................. 5
Hypotheses ......................................... 6
General Approach ................................. 6
Hypotheses ..................................... 7
Organization of Study ................................... 8
CHAPTER 2 .
DESCRIPTION OF THE ORGANIC AND CONVENTIONAL FARMING SYSTEMS ..... 9
Selection of the Organic Farm ............................... 9
Description of the Region and County .......................... 10
Characteristics of the Organic Farm ........................... 12
Farm Management .................................... 13
Farm Labor ........................................ 18
Cropping Systems .................................... 18

Crop Rotations and Nutrient Management ................... l9

Tillage Practices ................................. 21

Animal Systems ..................................... 22

Inputs From Off-Farm .................................. 24

Farm Outputs ....................................... 24

Characteristics of the Conventional Farming System .................. 27
CHAPTER THREE

LITERATURE REVIEW ..................................... 28

Sustainability and Sustainable Agriculture ....................... 28

Systems Approaches ................................... 34

The Comparison of Organic and Conventional Agroecosystems ............ 37

Measurement of Sustainability ......................... 39

The Use of Energy Analysis in the Comparison Of Agroecosystems ...... 41

Labor Analysis as a Necessary Component of an Agricultural Energy Analysis

..................................... 43
Irreversibile Changes .............................. 44
F arm-Level Energy and Labor Analyses .................... 45
Energy Analyses of Individual Organisms and Soil Ecology .......... 49
CHAPTER FOUR
RESEARCH APPROACH .................................... 54
Selection of the Organic Farm .............................. 54
Use of a Composite Conventional Farming System ................... 54
System Boundaries .................................... 55
Data Collection Methods ........................... A ...... 56
Calculation of direct and indirect energy inputs and outputs .......... 57

vi

Internal and External Energy Resources .................... 57

Fertilizers and Manure .............................. 58
Pesticides .................................... 60
Fuel ....................................... 61
Farm Machinery ................................. 6]
Seeds ....................................... 62
Labor Inputs ................................... 65
Farm Outputs .................................. 66
Standardizing Yields for Soil Types ........................... 66
CHAPTER FIVE
RESULTS ............................................. 68
Crop and Dairy Yields .................................. 68
Energy Inputs, Outputs, and Flows ........................... 74
Solar Energy Inputs ............................... 74
Energy Inputs and Outputs for Individual Crops ................ 75
Energy Flows ....................................... 87
Labor Inputs ....................................... 89
Summary ......................................... 9]
CHAPTER SIX
CONCLUSIONS AND RECOMMENDATIONS ........................ 92
Hypothesis 1 and Conclusions .............................. 92
Hypothesis 2 and Conclusions .............................. 93
Hypothesis 3 and Conclusions .............................. 94
Hypothesis 4 and Conclusions .............................. 95
Implications ....................................... 97

vii

Recommendations for Future Research ......................... 97

BIBLIOGRAPHY ........................................ lOO

viii

Table 2.1

Table 4.1

.Table 4.2
Table 4.3
Table 4.4
Table 4.5
Table 4.6
Table 4.7

Table 5.1

Table 5.2

Table 5.3

Table 5.4

Table 5.5

LIST OF TABLES

Table of Crop Rotations on the Organic Farm .................. 20
The Nutrient Content and Embodied Energy of Dairy Manure

as Fertilizer ....................................... 59
The Embodied Energy of Commercial Fertilizers ................ 59
The Embodied Energy of Selected Herbicides .................. 60
Fuel Consumption for Conventional Farms .................... 61
Machine Embodied Energy .............................. 63
The Embodied Energy Content of Seeds Used in Crop Production ..... 65
Average Energy Contents of Farm Outputs .................... 66

Selected Crop Yields for Organic and Conventional Farming Systems
from 1989-1992 ..................................... 69

Energy Inputs and Outputs by Enterprise on 3 Conventional Versus
and Organic Farm for Corn and Soybeans .................... 76

Energy Inputs and Outputs by Enterprise on a Conventional Versus
an Organic Farm for Alfalfa and Winter Wheat ................. 77

Five Year Totals for Energy Input on Organic and Conventional Farm . . 85

Ratio of Energy Outputs to Labor Inputs for Organic and
Conventional Farming Systems ........................... 9O

ix

Figure 1.1
Figure 2.1
Figure 2.2

Figure 2.3
Figure 2.4
Figure 5.1
Figure 5.2
Figure 5.3
Figure 5.4
Figure 5.5
Figure 5.6

Figure 5.7

Figure 5.8

Figure 5.9

LIST OF FIGURES

The Hierarchy of Agroecosystems .......................... 4
Map showing the location of Ingham County, Michigan ............ 11
Map showing layout of fields on the organic farm ................ l4

Diagram showing the relationship of the farm family to external
forces, system inputs and outputs, and internal processes ........... 17

Diagram showing details of the organic farm physical and
biological processes .................................. 26

Corn Yields from 1989 to 1992 for Organic and Conventional
Farming Systems .................................... 70

Soybean Yields from 1989 to 1992 for Organic and Conventional
Farming Systems .................................... 70

Winter Wheat Yields from 1989 to 1992 for Organic and Conventional
Farming Systems .................................... 71

Alfalfa Yields from 1989 to 1992 for Organic and Conventional
Farming Systems .................................... 71

Milk Yields from 1989 to 1992 for Organic and Conventional
Farming Systems .................................... 72

Energy Outputs and Inputs, with Output/Input Ratios, for
Organic and Conventional Farming Systems ................... 79

Energy Outputs and External Inputs, with
Output/External Input Ratios, for Organic and Conventional
Farming Systems .................................... 79

Distribution of Energy Inputs to Conventional Farming Systems

‘ by Input Categories ................................... 81

Distribution of Energy Inputs to Organic Farming Systems by
Input Categories ..................................... 82

Figure 5.10 Distribution of Energy Inputs to Organic and Conventional
Crop Rotations by Input Categories ......................... 86

Figure 5.11 Crop Energy Outputs per Labor Hour for and Organic and
Several Conventional Farm Labor Budgets .................... 90

xi

CHAPTER ONE
INTRODUCTION

Expanding human populations will demand more food and fiber well into the let
century. Agricultural production must keep pace with population growth if we are not to lose
ground in our efforts to feed and clothe the planet's people.

Production growth may come about through more intensive cultivation of existing farm
land, cultivation of new land, use of improved genetic varieties of plants and animals, and
through improved storage, transportation, and marketing. Experience suggests that production
gains are likely to be achieved at the expense of natural systems, environmental quality, and rural
communities unless we adopt new approaches to agriculture (Lowrance, Hendrix, and Odum
1986)

Some approaches to agriculture designed to avoid the problems mentioned above are
described as alternative, sustainable, ecological, regenerative, and low-input sustainable
agriculture. These terms refer to farming systems that tend to incorporate a number of similar
practices, but that also may have qualitatively distinct emphases (Reganold, Papendick, and Parr
1990). Some of the distinctions will be covered in the literature review. Common practices
usually include multi-year crop rotations, less use of fossil-fuel based fertilizers and pesticides,
cover crops, more diversified cropping and animal systems, more integrated cropping and animal
systems, and the use of mechanical and biological means, rather than chemical applications, to
control pests. Alternative agriculture is the term used in this paper to refer to these farming

systems.

2

Organic agriculture is one form of alternative agriculture. Organic farms differ from
the alternative farming systems described above by rejecting all fossil fuel-based and synthetic
soil, animal, and plant inputs.

Alternative agriculture, however, is more than the use of certain agricultural practices; it
is a systems-level approach to understanding complex interactions within agroecosystems,
guided by a philosophy of reliance on internal resources (Reganold, Papendick, and Parr 1990).
The common ground among alternative agroecosystems lies less in the actual practices
themselves than in the processes used to select and evaluate practices.

Conventional agriculture is the predominant farming practices, methods, and systems
used in a region."(BenbrOOk 1991, 5). As such, it varies over time, and according to
environmental and social factors. This definition also implies that some conventional farming
practices are sustainable, according to definitions presented later in this paper, when applied
appropriately (Benbrook 1991). Conventional agriculture as practiced in the region of interest
for this study will be defined operationally in Chapter 2.

This research study investigates differences in energy and labor flows through two
qualitatively different farming systems. The purpose is to determine which of the systems is
more "sustainable," according to definitions and criteria that will be presented below. It

examines resource management practices associated with organic and conventional farming

Operations and how they affect Welds. the W1, and the labor
inpuLpeLunitQfiQutnut on the farming systems studied.

Agroecosystems Defined
Agricultural production takes place within agricultural ecosystems, or agroecosystems.
Natural ecosystems are the starting point for all agricultural systems. Agriculture depends on
basic biological and ecological processes—photosynthesis, respiration, reproduction, herbivory,

competition, symbiosis, and others. These processes are modified by humans using cultivation,

3
irrigation, fertilization, and other agricultural processes. Agricultural processes, in turn, are a
function Of human decisions, derived from social and economic institutions and personal goals.
The resulting systems are as much social and economic systems as they are ecological, with
social, economic, and physical boundaries (Conway 1990). It is these systems that are referred
to as agroecosystems.

The concept of a hierarchy of agroecosystems further illuminates the definition above.
Lowrance, Hendrix, and Odum (1986) presented what they call a "hierarchical approach" to
agriculture which divided agroecosystems into a hierarchy of four main levels. The first level is
the field, followed by the farm, watershed or region, and the nation and world levels. Finer
distinctions can be made. A single milk cow can be considered as a distinct agroecosystem
(Conway 1990), and intermediate systems can be described up to the world level.

At the farm level of this hierarchy, a farming system can be defined as a unique and
reasonably stable arrangement of farm enterprises that the farm household or managers manage
via clear and definable practices in response to physical, biological and socioeconomic
environments, according to the goals, preferences, needs, and resources of the decision makers.
Resources include land, labor, capital, and management (Shaner, Philipp, and Schmehl 1982).

Each agroecosystem makes up a subsystem of the next level of the hierarchy. Higher
level agroecosystems generally have priority of action over those of lower levels, and have
longer management horizons, or are concerned with longer-term behavior (Lowrance, Hendrix,
and Odum 1986).

Social and economic processes become more important the higher up in the hierarchy a
level is, but ecological processes, the foundation of the hierarchy, remain crucial (Conway 1990).

In a similar manner, sustainability has a different meaning, and is constrained or enhanced by

World

 

Nation
1
Region
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I
Community
Houslehold
I
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Figure 1.1 The hierarchy of agroecosystems (adapted fromLowrance, Hendrix, and
Odum 1986; and Conway 1990)

5
different factors, at each level of the agroecosystem hierarchy (Lowrance, Hendrix, and Odum
1986).

It is important to realize that each level is much more than the sum of the preceding
levels. It is qualitatively distinct, and possesses singular and emergent properties that cannot
be deduced from the behavior of the constituent subsystems. Mario Bunge states two rules for
studying systems, an approach he calls moderate reductionism:

'1. "Start by studying every system at its own level. Once you have described it

and found its patterns of behavior, try to explain the latter in terms of the

components of the system and the mutual actions among them."

2. "Look for relations among theories, and particularly for relations among

theories concerning different levels. Never skip any levels. If reduction (full or

partial) fails, give up at least pro tempore." (Bunge, 1977, p. R80)

One of the premises of this paper is that much of contemporary agricultural research has
inappropriately reduced agriculture to simple field level, agronomic practices, concentrating on
inputs and outputs in a linear fashion. This reduction has failed to adequately describe the
singular and emergent properties of agroecosystems, and a higher system-level approach is
needed.

Open and Closed Agroecosystems

Agroecosystems can be characterized as relatively open or closed systems. In their most
elemental form, Open systems are linear production systems in which raw materials are
consumed to create a product, the product is sold and consumed, and waste products are
discarded into the environment. Open systems depend upon high input rates of raw materials,
simplified and specialized processing steps, and sites for waste disposal (Edens and Haynes
1982; Lampkin 1986; van Mansvelt 1986). A confined animal feeding operation is a good
example of an agroecosystem with relatively open cycles. A key factor in modern open systems

is an extensive transportation network making long trade routes possible (Edens and Haynes

1982). Transportation and marketing expenses of agricultural inputs and products have

6
traditionally been ignored by those evaluating modern U.S. conventional agriculture, yet they are
crucial to its existence. The exclusion of these costs has given us an overly positive View of the
relative benefits and costs of this dominant agroecosystem.

Closed systems are those that minimize inputs, that maximize the number of production
cycles for a given factor of production, and that minimize and recycle waste products back into
production inputs or products (Edens and Haynes 1982; Lampkin 1986). Climax ecosystems
perhaps bear the closest resemblance to closed systems. Nutrient inputs are very low compared
to nutrient levels in the system, and nutrients are recycled to very high degrees; the nutrient and
material cycles are relatively closed. Because society depends upon the export of food and fiber
from farming systems, contemporary agroecosystems cannot be completely closed. A relatively
closed agroecosystem could be described as one in which energy inputs to the system are small
compared to the amount of captured solar energy, and energy exports from the farming system
do not exceed the amount of solar energy captured directly by crops, and indirectly by farm
animals.

Hypotheses
General Approach

A central premise of this study is that the sustainability of an agroecosystem is directly
related to its degree Of Openness. While sustainability has been variously described as the ability
of the agroecosystem to maintain productivity when subject to major disturbing forces or shocks
(Conway 1991, 1990, 1986; Marten 1988; MacKay 1989), as food sufficiency, stewardship, and
community (Douglass 1984; Douglass 1985); this study will focus on a subset of these criteria.

Three main variables will be used to represent sustainability: yields per unit of land (or cow),

energy input per unit of crop output, and labor inputs per unit of crop and milk output.

 

7
As used in this study, energy is the sum of direct and indirect inputs (in units of
kilocalories), of the embodied energy Of an input, plus the energy required to produce and
transport the input to the farm. The degree of Openness in farm cycles will be characterized by
considering the organic farm as a relatively closed system, and conventional farming systems as
relatively open. The organic farm does not use any inputs of commercial fertilizer or pesticides,
and so compared to conventional farming systems inputs are minimized, and nutrient cycling is
increased; the organic system is relatively more closed than the conventional system. As used in
this study labor is the total of all time reported spent on a particular enterprise.
Hypotheses
Based on the considerations discussed above, the following hypotheses were developed
as the basis for comparing two qualitatively distinct agroecosystems.
Hypothesis 1. The organic farm will require less non-solar energy per unit of output than the
Michigan average.‘
Hypothesis 2. The organic farm crop yields will be equivalent to Michigan averages
Hypothesis 3. The organic farm milk production per animal will be equivalent to Michigan
averages
Hypothesis 4. The organic farm will require more labor per unit of output than the Michigan
average.
The organic farm's crop yields will be compared to those of conventional farms in
Michigan, and where possible, to farms in the same county. The crops to be compared will

include com, soybean, winter wheat, and alfalfa. Yields in bushels or tons per acre will be

 

1

As used in this study, the Michigan average is determined from state yields, and from fertilizer,
pesticide, tillage, and other management techniques used by farmers in a small watershed
adjacent to the organic farm.

8

contrasted, and the two agroecosystems' productivity will be compared based on the amount of
energy inputs needed to produce a unit of output.

Energy inputs will be determined by measuring all inputs to a given system, and
converting the inputs into energy units.

The labor productivity of the two agroecosystems will be measured by comparing the
hours of human labor required to produce a unit of output.

Organization of Study

The following chapters include a review of previous farming systems energy studies and
related research. The research methods of the study will then be discussed. The results of the
study follow, and conclusions based on the results of the study are then presented. The general
and the specific research hypotheses will be re-examined in light of the results and conclusions.

Recommendations based on this analysis will be Offered, with the goal of assisting
policy makers and researchers towards more effective, efficient, and sustainable solutions to our
agricultural problems. Information on the yields and the labor productivity of the two
agroecosystems will allow state and local extension agents to provide current and accurate data
to Michigan farmers interested in reducing fossil fuel-based farm inputs. The study will identify
production methods that may have great utility if future energy prices and availability constrain
farm management Options. The study will also demonstrate an approach towards comparative

analyses of sustainability.

CHAPTER 2
DESCRIPTION OF THE ORGANIC AND CONVENTIONAL FARMING SYSTEMS

In this chapter the organic and conventional farming systems studied will be described.
The characteristic elements of the two farming systems will be discussed, and the reasons for
selecting the particular systems studied will be presented.

Selection of the Organic Farm

There were several reasons for selecting the organic farm researched in this study. It is a
relatively closed-system farm, which has been managed without any petrochemical-based
fertilizers or pesticides or purchased fertilizers or pesticides since 1986, and it produces all of the
animal forage consumed by the dairy herd. The herd consumes all of the forage grown, and the
farm provides much of the feed grain consumed by the herd as well; as a result, nutrients are
retained on-farm in the manure. Seed for cover crops and small grain crops is also grown on the
farm. .

The entire farm has been managed organically for over six years. This means it has
passed through all or most of the transition effects that cause changes throughout an
agroecosystem during a change from conventional to organic farming methods. Transition
effects can be observed for a minimum of three years, and frequently for up to six years or more
(Dabbert and Maddden 1986, Harwood 1985). The effects are usually most severe during the
first several years of the changeover. Some of the biological transition effects are changes in soil
ecology, in pest populations, distributions, and species; and in nutrient cycling (Dabbert and
Maddden 1986, Harwood 1985). There is a learning transition effect as well. Farmers must

learn how to manage their farms without fossil fuel-based inputs, and may have a steep learning

10
curve to climb before they gain sufficient experience and expertise with organic techniques
(Dabbert and Madden 1986).

The organic farm was also chosen because in many ways it is typical of moderate sized,
mixed-enterprise dairy farms in Michigan and the Great Lakes region. In 1987 there were over
800 dairy farms in Michigan with herd sizes similar to the one chosen, 36 of them in Ingham
County alone (Census 1989).

Most importantly, the organic farm was chosen because the farmer was willing to work
with the researcher. His farm is also one of those close enough to the university to keep
telephone and travel costs low.

Description of the Region and County

The organic farm is located in Ingham County in south central Michigan. Figure 2.1
shows the location of the county.

The region is characterized by broad stretches of gently sloping ground moraine that
form a plain interrupted by end-moraine ridges and outwash channels. Soils are moderately well
to well drained loams. The ground moraine consists Of well and moderately well drained rises,
and poorly to very poorly drained depressions. The ground moraine has less than 50 feet of
difference in elevation over areas of several miles (Albert, Denton, and Barnes 1986). The end
moraine tends to form narrow bands, from 1 to 3 miles wide, of low ridges (less than 50 feet) and
swampy depressions. Most of the end moraine ridges are too steep for row crops. The average
elevation of the region is 840 feet above mean sea level (Albert, Denton, and Barnes 1986).

Beech-sugar maple forests are typical on most of the ground and end moraine. Common
species are black maple, pignut hickory, basswood, red oak, and white ash. Drier end moraine

ridges support oak-hickory forests dominated by red and white oak.

11

 

 

 

 

 

 

 

Figure 2.1 . Map showing the location of Ingham County, Michigan

12
Poorly drained depressions support moist and swamp communities dominated by American elm,
red ash, silver maple, and swamp white oak (Albert, Denton, and Barnes 1986).

The region averages 31.5 inches of precipitation per year, half of it during the growing
season from May to September. The average annual temperature is 47.7 °F. The average
temperature from May to September is 65.3 °F. The region's growing season averages 146 days
(Albert, Denton, and Barnes 1986).

The infi'astructure of the area is well developed. The county is served by all-season
roads and rail, and air service is available nearby. The organic farm is served by electrical and
natural gas utilities, and physical access to markets for buying and selling farm inputs and
outputs is not a problem.

In 1978, agriculture was the primary land use in Ingham County by a wide margin,
followed by use for residential dwellings, open shrub and grasslands, and lowland and upland
forests (Planning and Zoning 1990). In spite of its role as the leading land use in Ingham
County, agriculture contributed only 0.5% percent of total county earnings in 1988. This
compares to an average of 3.0 percent for agriculture in rural Michigan counties, and an average
of 0.9 percent for all Michigan counties (MI Dept. of Commerce 1990). Compared to the rest of
the state, opportunities for Off-farm employment are better than average. Unemployment in the
county has consistently been at least two or three percentage points below the state average (MI
Dept. Of Commerce 1990).

Characteristics of the Organic Farm

Unless otherwise indicated, all information about the organic farm was collected during
interviews with the farmer and his wife, or from farm records (Anon. 1992).

The organic farm is approximately 380 acres in size. The family owns 260 acres and
rents an additional 120 acres from a relative. There are about 335 tillable acres of predominately

sandy-loam soil, with patches of loam and muck. The potential for erosion on the farm soils is

13
low to moderate, varying by the slope of the land (SCS-USDA 1979). None of the land is
irrigated, and only about 2 percent of the farm is tiled for drainage. Much of the 45 acres of non-
tillable land lies in and along the banks Of a permanent creek that runs through the property. The
remainder of the non-tillable land consists of poorly drained muck soils that are usually too wet
to work with machinery and too far from the barns and milking parlor to graze cattle. As of the
fall of 1992 there were 28 milking cows and about the same number of replacements on the farm.
The family also keeps approximately 60 laying chickens at a given time. Figure 2.2 shows a
map of the organic farm.

The organic farmer grew up in the area on his family's poultry farm, located on the land
he now rents. It was there that he started his dairy herd and farming. He and his wife, who does
not come from a farm background, have two boys and a girl, from 9 to 17 years old. The farm
provides about half of the household's cash income, and his wife's off-farm job provides the
other half, as well as health insurance benefits.

Farm Management

The organic farmer manages the farm and makes the final decisions on virtually all farm
matters. His wife provides input, particularly on matters relating to how much time the organic
farmer allocates to different farm subsystems, and on any qualitative changes in the farm. For
example, she played a significant role in their decision to change to organic practices.

They began to convert their farm from conventional to organic practices in 1980. The
conversion was started slowly, by leaving synthetic fertilizer off one field the first year of the
transition. By 1985 no purchased fertilizer was being used. Pesticides were stopped by 1986.

By 1991 all the fields and cultural practices were certified as organic by

14

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the Organic Crop Improvement Association. This certifies that no fossil fuel-based fertilizers or
pesticides have been applied for at least three years. The farmer said that he found government
farm programs, particularly the set-aside program, helpful in making the transition to the use of
on-farm resources. He said that using organic techniques means his input costs are quite a bit
lower than conventional systems, but economic considerations were not cited as key factors in
their decision to convert to organic methods. He stressed the fact that he isn't really trying to
maximize net profit; instead, he's trying to make a living without killing the soil, and that
farmers and others need to recognize that nature sets limits, and we have to abide by them or pay
the price. In other words, he is trying to emimize his net profit, and his farm's biological and
economic productivity and well-being, within the constraints that result from not using synthetic
off-farm fertilizers and pesticides.

The farmer commented during research interviews on the social sustainability of
conventional farming systems and on the ability of this system to support economically and
socially healthy rural communities. He said within the past 25 years the biggest change he's
noticed in the area is the decline in the number of farm families in the area. Twenty-five years
ago farms had livestock, children, and at least some of their income was from farming. Now,
farms have been abandoned. He said he has seen a switch toward absentee ownership, and some
farms have been bought out and rented to other farmers. He thinks single houses and housing
projects will be coming to his area soon, built on former farms, because there's not enough
money in conventional farming compared to other occupations. He is skeptical of agricultural
technologies introduced during the past thirty years, saying he'thinks few of them have really
made life better for farm families, and that, based on changes in farm and rural population, and
social welfare criteria, things haven't really improved. He thinks that, based on the history of

previous attempts, laws and programs to correct some of these problems probably won't work.

16
One reason he is interested in organic farming is because he thinks it could resolve some of these
dilemmas.

Figure 2.3 shows the relationship of the farm family to external forces acting on the
farming system, to the system inputs and outputs, and to the internal physical and biological
processes on the farm itself. While the farm family decides the amount and type of materials to
import and export from the farm, external forces control the availability and price of those
materials. The farm family provides physical flows to the farming system as labor inputs, and
control flows as management decisions. Some outputs from farm subsystems, such as feed,
manure and seed, are returned as inputs to the same or other farm susbsytems without leaving the
farming system boundaries. A very small fraction of the farm output is consumed directly by the
organic farm family, in the form Of eggs, milk, chicken, and beef, though Off-farm labor may

first be used for processing the products.

17

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18
Farm Labor

The farmer provides all but a small fraction of the labor for the organic farm. Neither
his wife nor his children spend any significant time on field operations. However, his wife's off-
farm job does provide the family with a degree of financial security, as well as benefits such as
health insurance. A local teenager is employed for approximately two hours a day to do the
evening milking and a few other chores. Local teenagers also help load and stack hay in the
summer. He said finding teenagers to work isn't usually a problem, and they provide the balance
of the labor needed to work the farm.

Cropping Systems

The total acreage of cash, pasture, and cover crops grown on the organic farm over the
four years from 1989 to 1992 ranged from 118 to 151 percent of the total tillable acreage. This
increases to 123 to 157 percent of tillable acres if land in permanent pasture is excluded. Over
the past four years the organic farmer has grown from 1.2 to 1.5 crops per field per yield. The
low end of this range represents 1992, a year when poor weather prevented the farmer from
harvesting corn and soybean in a timely manner, and keeping him from sowing cover crops for
the remainder of the year.

The organic farmer grew from 110 to 160 acres of cash grains each year between 1989
and 1992, including com, soybeans, and winter wheat, at least part of which he sells off-farm.
During this time he also grew 12 to 53 acres per year of barley and oats. He had planned to pearl
his organic barley, and sell it for a premium, but was unable to locate a suitable mill close
enough to make it profitable.

Thirty acres of the farm were kept in permanent pasture between 1989 and 1992. From
40 to 136 acres of alfalfa for cattle feed were grown during each of these years. Ninety-five to
one hundred-ninety acres were kept in cover crops of rye grain (rye), a rye-hairy vetch blend, or

hairy vetch for at least part of each year from 1989 to 1992.

19

Between 1989 and 1992 20 to 60 acres Of the farm were idle or in government set-aside
programs. The farmer did not participate in the set aside program in 1990 and 1991, believing
that the benefits Of the program would not compensate him for the costs of applying and filling
out the necessary paperwork, and lost income from his cash crops.

Crop Rotations and Nutrient Management

A set crop rotation plan is not followed on the organic farm. Instead, rotations are
decided using opportunistic management techniques. The succession of crops is varied
according to estimates Of the availability of nutrients, the weather, labor schedules, market
conditions, and other factors. However, certain patterns or trends emerge when crop histories are
examined. Corn almost always follows a legume other than soybeans, typically vetch, a rye-
vetch mix, or alfalfa. This is done to supply the corn with as much nitrogen as possible.
Soybeans usually follow corn, though sometimes a small grain such as oats is used. Soybeans
are often followed by a cover crop of rye or rye-vetch, or with another small grain, such as
winter wheat.

Judging from a four year history of his crop rotations, the farmer tries to grow a cover
crop that will be plowed down at least once every three or four years, and on a number Of his
fields cover crops have ben grown for at least part of two or three crop years in succession. Crop
rotations and cover crops are used to maintain farm productivity, to capture nutrients and cycle
them in the fields, and to prevent soil erosion. Table 2.1 shows a summary of the crop history of

the organic farm fields.

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

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21
Commercial inoculum is used with hairy vetch and soybeans to ensure an ample population of
nitrogen-fixing symbiotic bacteria.

The farmer speculates that rye and other cover crops may be absorbing plant nutrients
such as phosphorous (P) and potassium (K) from deeper in the soil, below cash crop root zones,
or may be taking up forms of nutrients that cash crops cannot absorb. This was advanced as one
reason soil tests on the farm have shown little or no change in the levels of N, P, and K since
synthetic fertilizer applications were halted.

Dairy manure is applied to fields, but because of the small size of the dairy herd, most
fields are covered once every four or five years on average at normal spreading rates Of 5 or 10
tons per acre. Manure spreading retains nutrients on the farm, particularly P and K. In the forms
found in manure these nutrients are less volatile than N sources in manure, such as ammonia, nor
are they subject to the types of processes that lead to denitrification and loss of N to the
atmosphere (NRC 1989, Rosswall 1981).

Tillage Practices

Fields are first prepared for the planting of corn, soybeans, and some small grains with
the use of a moldboard plow. They are then disked once or twice, harrowed with a roller harrow,
and planted. Four or more passes may be made over a field before planting.

A moldboard plow is used to incorporate cover crops into fields and to disrupt weed
growth. Despite evidence that moldboard plowing can increase soil erosion, the farmer believes
erosion from his fields is less than, or at least no worse than, erosion from his neighbors' fields,
due to his use of Cover crops, and the absorbency of his soil. He said that since he has switched
to organic methods, and started planting and incorporating cover crops, his soil organic matter
has increased and his soil has better structure. It does not compact as much, it is more absorbent,
and his fields are becoming easier to plow. His findings are similar to and supported by those of

Reganold, Elliot, and Unger (1987) and others, discussed in the literature review.

22

Rye, vetch, and some of the small grains are broadcast into the stubble of the previous
crop to plant them, after first disking the stubble. This reduces the number of tractor passes
necessary to plant from three or four to two.

Row crops are cultivated once or twice during the season to suppress weeds, and a rotary
hoe is also used once or twice each season to keep weed pressure down. The permanent pasture
is mowed or clipped twice each summer to encourage new growth for the cattle. Any land sitting
idle is usually disked and/or mown in order to keep weed populations down.

1 Animal Systems

The organic farmer keeps a dairy herd of 28 milking cows, with an equal number of
replacements. He also raises about 60 laying chickens. Cattle are fed a mixed ration of shelled
corn, oats, soy meal, molasses, trace minerals, and vitamins year-round. The cattle also have
access to as much hay as they want throughout the year. The hay is primarily alfalfa, with some
orchard grass. The soy meal, and sometimes the mineral salts, are discontinued for about three
months in the summer when the cattle are grazing. The cattle graze from approximately May 1
to November 1, but the quality of the grazing drops significantly after the first two or three
months, by which time the cattle are back to eating as much hay as ever.

At one point feed was mixed on-farm, but a local cO-op now prepares and mixes the
cattle feed from farm grain stored at the co-op. Any additional grain needed is purchased
through the cO-Op.

Cattle are fed at least some of the corn grown on the farm. Over the past four years all
hay consumed was grown on the farm, with the exception of one purchase of about one month's
worth of hay. The oats in the feed ration are grown on farm as well. ,

When there is only a small difference between the prices for commercial and organic
corn and soybeans the cattle are fed corn and soybeans grown on the farm. When the price

difference is larger, crops are sold for the organic premium, and less expensive commercial grain

23
is fed to the cattle. Barley grown on farm was fed to the cattle with no problems, when the
barley could not be pearled economically.

New-bom calves are kept on whole milk for two months, and then started on the regular
ration, supplemented with protein. Cattle are not sold for breeding purposes. The organic
farmer said he has considered getting out of dairy farming, selling Off the adult herd, and raising
the replacements and selling them. He said he is tired of working for milk prices similar to those
of 1970.2

Cattle are kept in tie stalls in a barn close to the household, and heifers stay in a free-stall
barn. All cattle go outside every day for exercise. Gutters are cleaned mechanically. The
farmer uses a pipeline milker, and feeds with two feed carts. He said that he has a low mastitis
incidence, which he credits to his relatively natural feeding system and an emphasis on
cleanliness. Antibiotics are used if needed, but they are not used as a matter of course, nor are
subtherapeutic doses of antibiotics fed to the cattle.

The chickens are fed a commercial layer mash, purchased Off-farm, supplemented with
soybean and grain screenings from the farm crops. This is a very small off-farm input. The
chickens are allowed to range, and live in a portion of the equipment barn.

The organic farmer does not keep any bees, and does not know of any neighbors who do.
He does not rent bees, and said he has not noticed any problems with pollination. He thinks
there are enough trees and woodlots in the area, especially along the creek, to provide habitat for

ample populations of wild and feral bees.

 

2

He sold his dairy cows in February of 1993, and plans to raise replacements to milking age,
when he will consider the milk market. He said that he can't imagine farming without some sort
of animal component, but is not sure what that might be.

24
Inputs From Off-Farm

No fossil fuel-based fertilizers, insecticides, or herbicides are purchased or used on the
organic farm. In keeping with a philosophy of reliance on internal resources, organic fertilizers
or pesticides are not purchased either. The primary material inputs from off-farm sources are
machinery, including tractors, tillage equipment, and dairy equipment; and energy inputs of
diesel fuel, gasoline, electricity, and natural gas. Off-farm inputs also include vital biological
inputs in the form of seed, inoculum, and sperm and breeding stock for the dairy herd. Seed for
future crops is saved from the harvest of a number of small grain and cover crops. Winter wheat,
oats, rye, and hairy vetch are grown from seed harvested on farm.

There is also a flow of information from off-farm sources onto the farm. The organic
farmer said his chief sources of off-farm information are other farmers, the OCIA (Organic Crop
Improvement Association), the Rodale Research Center, and a few organic farming magazines.
He said when he first started farming he tried to attend one or two seminars each winter at
Michigan State University (MSU), and said that seminars can be a time-efficient way to get
information. He said it has become easier to get information on organic farming over the years,
and that there is now more information available, and institutions are opening up. Figure 2.4
shows some of the details of the physical and biological processes on the organic farm.

Farm Outputs

Milk is the most important farm product economically. Milk is sold to a local dairy co-
op. Male calves are sold to beef producers, and herd culls are sold to meat processors. No cattle
are sold for breeding purposes.

Com,'soybeans, and winter wheat are sold through a local farm co—op, and are sold for
organic premiums whenever possible. The organic farmer estimates his corn yields are about 85

to 90 percent of those he could get using conventional techniques on his_fann.

25

A small number of eggs are sold through local food co—ops for a premium price. Some
hairy vetch seed is sold to neighboring farms, but is not a significant source of income.

Between 1989 and 1991 about 1.5 acres of vegetables and fruit were grown each year for
organic markets. This included melons, squash, tomatoes, green beans, and sweet corn. The
farmer said they did extremely well one year, but had trouble with weeds and the weather the
other two years, so they stopped growing produce in 1992 for the time being.

Information is also exported from the organic farm. On-farm trials of different
techniques are conducted with the Rodale Research Center and the Michigan Agricultural
Stewardship Association. The organic farmer speaks to farm groups, gives farm tours, and in
general shares his knowledge and experience in organic farming techniques with those willing to

speak with him, as this researcher can thankfully attest.

26

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Characteristics of the Conventional Farming System

A "composite" conventional farming system was used in this study for several reasons.
It made it easier to develop a mixed-enterprise conventional system more comparable to the
organic farm. The data used for the conventional farming system came from farms in the same
county as the organic farm. The creation and use of a composite system meant that information
comparable to the organic farm was available. It also eliminated the risk of the conventional
farmer withdrawing from the study, or being unavailable to work with the researcher.

The conventional farming system used to compare to the organic system is based on
research conducted by the Ingham County Cooperative Extension Service (MSU-CES) and the
Ingham County Soil Conservation Service, in conjunction with the Sycamore Creek Water
Quality Program. Sycamore Creek flows through Ingham County, and the farms studied are
located in the county. As part of the program, extension and conservation agents determined
typical rates of fertilizer and pesticide applications for different crops in the county. They
described the major crop rotation of the watershed as a com-com-corn-soybean-wheat rotation.

The fertilizer and nutrient rates used in the Sycamore Creek program were used for the
conventional farming system in this study. The rotation was used for a comparison of crop
rotations as well.

Crop and milk yields used for the conventional system are state averages for the year in
question. County averages were also used whenpossible. Labor data were compiled from three
farm labor budgets.

Details on the conventional farming system, and on the assumptions used, are presented

in Chapter Four: Research Approach.

CHAPTER THREE
LITERATURE REVIEW

This literature review examines definitions of sustainability and sustainable agriculture,
the nature of sustainability, and some of the techniques proposed for measuring and quantifying
agricultural sustainability. It then considers systems science and systems approaches, and their
use in studying agroecosystems. A review of several farming systems comparisons and their
results, including a discussion of qualitative differences-and similarities between conventional
and alternative farming systems, concludes the chapter.

Sustainability and Sustainable Agriculture

"When I use a word, it means just what I choose it to mean..." So says Humpty Dumpty
in Lewis Carroll's IhmughjheLgekingfliaes (Carroll p. 23 8, no date). Some authors claim that
many writers and researchers today use the terms "sustainable" and "sustainability" in a similar
manner. Conway (1991), Lockeretz (1988) and Crews, Mohler, and Power (1991) agree that
"sustainability" and "sustainable agriculture" have too often been used to mean all things to all
people, and they argue that these terms are losing credibility as result. A lack of consistent and
clear definitions also allows critics of alternative agricultural methods to claim that conventional
techniques are sustainable, and that needed agricultural research has been or is being conducted
(Buttel and Youngberg 1985, Lowrance 1988). We will see, however, that consensus on the
meaning of sustainability and sustainable agriculture has emerged in several areas.

Lockeretz (1988) points out possible differences between the more common terms (e.g.,
sustainable, alternative, low-input, ecological, and regenerative) used to describe agroecosystems
that share goals such as less use of non-renewable and off-farm inputs and conservation and

improvement of natural resources. He discusses the possibility that there are indeed

28

29
fundamentally different concepts involved, but that authors are not always precise in selecting
the appropriate term. In literal terms, he says (Lockeretz 1988) :

"sustainable" describes the ability to endure over time.

"alternative" refers to practices different from present or "conventional" norms.

"low input" refers to the decreased use of goods and services from outside farm
boundaries.

"regenerative" implies the ability to improve the natural resource base (some also
include improving social resources).

"ecological" brings to mind natural environmental laws and processes.

He grants the possibility that these terms do refer to the same basic concepts, but that
different ones are used to avoid negative connotations of previous terms, or to capture nuances
writers believe previous terms did not.

In contrast to these primarily semantic issues, he introduces the possibility that the basic
concepts implied by the different terms are different, but the same agroecosystems tend to be
used to demonstrate these different concepts. Studies that used only the term "organic" have
been cited as dealing with "low input," "sustainable," and ecological " agriculture (Lockeretz

1988). This begs the question of whether or not such systems are "sustainable, alternative," or
"regenerative." Lockeretz (1988) states each of these terms is a goal, independent and unique,
and that at least some of them may be mutually exclusive for specific production systems.
Conway (1991) believes broad and sweeping definitions of sustainability are useful as
policy statements, but don't meet the needs of agricultural researchers and farmers, who need a
practicable, scientific definition open to testing and experimentation. He and others define
sustainability as the ability of the agroecosystem to maintain productivity when subject to major

disturbing forces or shocks (Conway 1991, 1990, 1986; Marten 1988; MacKay 1989). This is

similar to Lockeretz's (1988) definition, and that proposed by Crews, Mohler and Power (1991).

30
Others, while admitting the usefulness of this definition, say that this definition is another term
for the ecological concept of resilience (Lynarn and Herdt 1989, Harrington 1992).

Crews, Mohler, and Power (1991) state unequivocally that definitions of sustainable
agriculture that embrace ecological, sociological, and economic characteristics are excessively
broad, and blur critical distinctions. They support a definition closer to Conway's. They
maintain that sustainability is a measure of a system's ability to endure, and is constrained only
by ecological conditions. They enthusiastically support efforts to increase equity, rural quality
of life, and social justice, but they hold that these issues should be considered in their own right,
and not crammed under the overburdened umbrella of sustainability.

Researchers also distinguish between a number of different types of agricultural
sustainability. Douglass (1984 and 1985) delineates three views: sustainability as food
sufficiency, as stewardship, and as community. Sustainability as food sufficiency, he says, is
defined as the ability to produce enough food to meet the demand of present and future
generations. Those embracing this view tend to believe that any production methods that yield
marginal benefits greater than marginal costs are justifiable, even if agricultural production
needed to meet food demands leads to resource use and degradation exceeding its regenerative
capacity (Douglass 1984).

Sustainability as stewardship focuses on ecological approaches and perspectives, seeking
to optimize farm outputs indefinitely while maintaining or enhancing the natural resource base
farms depend on (Douglass 1985 and 1984). Supporters are interested in reducing population
growth, the consumption of nonrenewable resources, and negative extemalities caused by
agricultural production. They tend to challenge the concept of dynamic economic efficiency as
calculated using cost/benefit analysis, declaring that the ethics of the current generation

discounting benefits accruing to future generations are dubious (Harrington 1991; Ben'y 1977).

31
Churchman (1984) also raises pointed questions about the morality of intergenerational
willingness-tO-pay models of allocating natural resources.

Proponents of sustainability as community hold that trends towards larger farms, and
towards corporate farms, have had severe negative consequences on the quality of life in rural
communities. These trends have negatively affected the ability of of farm families to maintain
their consumption and livelihood. They believe it's necessary to extend stewardship to include
not only ecologically sound practices, but agricultural systems that will strengthen social
relations and structures, and encourage a culture of mutual concern and interest (Douglass 1984;
Berry 1977).

Lowrance, Hendrix, and Odum (1986) also distinguish between several types of
sustainability. They presented what they call a "hierarchical approach" to agriculture which
divided agriculture into a number of levels, reflecting the different systems which dominate the
level. Figure 1.1 is a diagram of one view of agroecosystem hierarchies. Sustainability has a
different meaning at each level of the hierarchy. At the bottom, agronomic sustainability refers
to the ability of a unit of land to maintain long-term production. Microeconomic sustainability is
the ability of the farm to stay in business. At the watershed or landscape levels ecological
considerations must be addressed; and government policies control macroeconomic
sustainability at the regional, national and international level. In this approach, higher level
subsystems generally have priority of action over lower level subsystems, and have longer
management horizons, or are concerned with longer-term behavior. They discuss a flaw in this '
view, in that macroeconomic subsystems seldom have a longer time frame than ecological
subsystems. Brown et al (1987) concur with a hierarchical approach, stating that the meaning of
sustainability depends upon the dimensions, and the level of the agroecosystem hierarchy, we

consider.

32

The author suggests that the concept of "sustainability" is best used in a relatively
narrow sense meaning the ability to maintain production (desirable outputs) over time, in the
face of significant disturbances or pressures.3 This allows researchers and writers to specify key
terms in the meaning (e.g. production, outputs, time, disturbances) to present an unambiguous
operational definition. This is similar to the way the term "productivity" is presently used. It is
understood to be the output of goods or services per unit of input. Every writer or researcher
must specify what particular outputs and inputs are of interest, yet there is general agreement as
to what "productivity means. "Sustainability" will be used according to this definition in this
paper.

The term "sustainable agriculture" incorporates a much broader spectrum. As defined in
the first chapter, agriculture systems (agroecosystems) are as much social and economic systems
as they are ecological, with social, economic, and physical bOundaries (Conway 1990). It
follows that a sustainable agriculture must address the sustainability of social, economic, and
physical systems making up an agroecosystem.

A number of researchers and public officials have proposed definitions that encompass
economic, social, and physical elements. Rep. George E. Brown (D-CA), wrote that
sustainability of agriculture, or sustainable agriculture, "..is a useful concept for focusing
agricultural research because it captures a diverse set of concerns about agriculture as an
economic system, and ecological system, and a social system." (Brown 1989 p. 102). Harwood
(1988 p.2) describes sustainable agriculture as "an agriculture that can evolve indefinitely toward
greater human utility, greater efficiency of resource use and a balance with the environment that

is favorable both to humans and to most other species." He describes this as a "framework"

 

3

Population growth, technological changes, the impacts of political and diplomatic policy
changes, and entropy, are examples of large-scale forces affecting the sustainability of
agroecosystems.

33
definition, that can be filled as needed with appropriate details over a relevant time frame
(Harwood 1988).

Hildebrand (1990) finesses the question of defining sustainable agriculture. He points
out that it can be thought of in economic, political, social, cultural, institutional, and ecological
terms; and then goes on to say that since so many people use the term, it is apparently intuitively
understandable. He says that sustainable agriculture is net a constant state, it is not a return to a
former state, nor is it necessarily low input.

Benbrook (1991 p. 4) defines sustainable agriculture as "...the production of food and
fiber using a system that increases the inherent productive capacity of natural and biological
resources in step with demand. At the same time, it must allow farmers to earn adequate profits,
provide consumers with wholesome, safe food, and minimize adverse impacts on the
environment. " Benbrook (1991) argues, and these representative definitions demonstrate, that
there seems to be a general consensus concerning the essential elements of sustainable
agriculture. Though different definitions emphasize different aspects, nearly all contain a
common set of features (Benbrook 1991).

The definitions presented above agree well with the view that sustainable agriculture is a
system-level 1219.99.55 of adaptation to complex ecological, economic, political, and social
interactions within the boundary of a given agroecosystem (Edens 1985; Reganold, Papendick,
and Parr 1990). Of course, so is conventional agriculture. However, the process and the
adaptations are qualitatively different. Because these two agroecosystems have distinct
emergent properties, systems-level approaches, at appropriate levels of the agroecosystem
hierarchy, are necessary to understand and compare them. Systems approaches will be addressed

in the following section.

34
Systems Approaches

Churchman (1968) says that the essential concept of a system is that it is made up of a
set of components that work together for the objective of the whole. Spedding (1979) defines
systems as a collection of objects and their relationships existing within a boundary that is drawn
by the observer, appropriate to his or her objectives. Systems, he says, are unaffected by their
own outputs, and their boundaries are based on the inclusion of all significant feedback. Bawden
(1991), and Bunge (1977) extend this approach, pointing out that systems arise from the
relationships and connections between their constituent parts, creating an assemblage with
unique and emergent properties. Elements within the assemblage are strongly interconnected
compared with connections to elements outside the assemblage, and as a result a system
responds to many outside forces as a whole, though only one element of the system may have
been acted upon (Edens and Haynes 1982; Conway, 1991).

Checkland (1981), and Atkinson and Checkland (1988) state the four most fundamental
systems ideas are emergence, hierarchy, communications, and control. Systems can also be
divided into two major types: those that have clear goals or predictable outcomes; and those with
ambiguous or uncertain goals and outcomes (Checkland 1981; Bawden et al 1984). The former
they call hard systems; the latter sofi systems. Bawden (1991) further distinguishes the two.
Hard systems approaches, or what he calls ontosystemic inquiry, are based on accepting and
studying entities as systems as they exist in the world—it is the study of ontological realities.
Episystemic, or soft system, study, he says, is the study of "...people's perceptions of reality, on
their mental processes rather than on the objects of those processes." (Bawden 1991, p. 2368).
Issues associated with the subject of study, such as an agroecosystem, "...are thought about as if
they were interrelated in some way or another." (Bawden 1991, p. 2367). While these

approaches are not mutually exclusive in a single research project, it may well be that they are

35
for a single researcher, due to the conceptual shift necessary to switch between these two world
views.

Checkland (1981) says that soft systems methodology is an iterative process for
investigating and acting upon real world problems. He summarizes the process in the following
steps. The first is finding out about a real world problem. The next step is naming or defining
some systems of purposeful activity relevant to the situation and its improvement. The systems
named are then modelled, based on transformations of real or abstract inputs into outputs. These
models are then compared with the real world activities, after which changes that are both
desirable and feasible are defined and debated. The final stage of this process in implementing
the changes selected (Checkland 1981; Atkinson and Checkland 1988).

They go on to state that practically all systems-based work is rooted in the concept of a
system as an adaptive whole that can react to a changing environment (Atkinson and Checkland
1988). They argue that soft systems methodology (SSM) is itself an adaptive whole, and the use
of models of purposeful systems within SSM also reflects the notion of systems as an adaptive
whole. They believe that the advantages of SSM could be weakened if the metaphor of systems
as an adaptive whole becomes too pervasive. They propose two alternatives to yield new images
of systems. One is to abandon the idea of systems as purposeful entities while retaining the
notions of wholeness and emergence. The adaptive and purposeful whole changes to something
better described by the metaphor of the net. A second possibility is to combine several
purposeful systems in more complex wholes that do not pursue a single purpose in a unitary
manner (Atkinson and Checkland 1988). Some of the systemic metaphors that follow from the
second choice are combative, contradictive, host/parasite, syndicalist, and imperialistic system I
(Atkinson and Checkland I988). Patten and Odum (1981) propose a definition of natural

ecosystems similar to this second possibility.

36

In a rebuttal of a paper by Engelberg and Boyarsky (1979), Iheflenexebemetielflamre
QflEeesysiems, Patten and Odum (1981) present a strong case for considering ecosystems as
cybernetic systems. They argue that variables such as production, respiration, population sizes,
and species diversity can be regarded as "..components of an objective function that is to be
maximized or minimized subject to a set of constraints." (Patten and Odum 1981 p. 889). They
say these can be regarded as analogues of goals in teleological systems, but that teleological
metaphors of ecosystems are just that.

They define cybernetic systems as a special class of input-output, or cause-and-effect
systems, for which input is determined at least in part by output. Feedback is output that is
returned to input, that can come to control the system. They go on to demonstrate that
ecosystems possess the necessary characteristics of cybernetic systems—analogues of goal
directedness, information networks, feedback, and regulation and stability. They state that the
true issue (well described by Engelberg and Boyarsky) is how to think about ecosystems and
place them in a scheme of known systems (Patten and Odum 1981). They describe ecosystems
as "the level of organization concerned with the orderly, not chaotic, processing of energy-
matter" controlled by feedback in the form of diffuse and decentralized informational processes
(Patten and Odum 1981 p. 894).

The Gaia hypotheses of Lovelock is perhaps the most striking example of this View.
Lovelock explicitly rejects arguments that his hypothesis implies or requires a teleological
system (Lovelock 1990). It is clear from his work that he views Gaia much the same as Patten
and Odum (1981) view ecosystems—as resulting from the coevolution of ecosystems through
energy, matter, and information flows and feedback cycles resulting in orderly, negentropic
populations and environments. The concurrence of their views is to be expected, for Lovelock

says he has felt a special empathy towards Eugene Odum's writings (Lovelock 1990).

37

Few would argue that farms are purposeful agroecosystems, controlled and guided by
owners or managers. However, even at the farm level system objectives may not be clear, or
may result only from comflicting or mutually exclusive human desires. At watershed and larger
levels of agroecosystems, the direction and amount of change over time in an agroecosystem can
best be thought of as a vector, resulting from and expressing all human and nonhuman forces
acting upon the system (Axinn 1988; Harwood 1992). Agroecosystems at these levels resemble
the complex wholes described by Atkinson and Checkland (1988), Patten and Odum (1981), and
Lovelock (1990), lacking a single purpose. Axinn's concept of change as a vector, resulting from
the interaction of reinforcing, opposing, or tangential biological, physical, technical, economic,
social, and political forces, offers a valuable tool for studying systems, such as large-scale
agroecosystems, that do not fit the metaphor of the adaptive whole (Axinn 1988).

In the next section methods of comparing organic and conventional farming systems,
and their sustainability, will be presented. Moderate reductionism, as suggested by Mario Bunge
(1977), will then be used to examine some of the singular and emergent properties of different
agroecosystem levels. In keeping with this approach, higher levels, such as national and
international levels, will be considered first. Intermediate and lower-level agroecosystems and
their properties will then be analyzed, and their usefulness in explaining higher-level system
properties will be considered. The advantages and disadvantages of energy analysis as a tool for
agroecosystem analysis in the context of moderate reductionism will be presented. The results of
previous whole-farm comparisons will be discussed, and some qualitative differences between
ecological processes on conventional and organic farms will be introduced to suggest causes for
differences observed in productivity and sustainability.

The Comparison of Organic and Conventional Agroecosystems

Agroecosystems can be compared on the basis of several system properties. These

properties—productivity, stability, sustainability, and equitability—can be specified and observed

38
(Conway 1990; Conway 1986; Marten 1988; Harrington 1992). Productivity is the net increment
in useful product per unit of resource or input; stability is the constancy of production despite
small, regular stresses (Conway 1990; Conway 1986; Marten 1988; Harrington 1992).
Sustainability, as previously defined, refers to the ability of a system to maintain productivity of
desirable goods and services when subject to major disturbances, or shock (after Crews, Mohler,
and Power 1991; Conway 1990). The equitability of a system is the evenness of distribution of a
system's productivity among beneficiaries, according to criteria mutually agreed upon by system
residents (after Conway 1990; Marten 1988). Marten (1988) includes amenemy as a key system
property, which he defines as the self-sufficiency of an agroecosystem.

Farmers and others place different values on the system properties above. There are
numerous tradeoffs possible for a single system property, and between system properties.
Subsistence farmers may emphasize land productivity; industrialized farmers tend to value labor
productivity (Marten 1988; Whyte 1991). Much of the US. agroecosystem appears to favor
productivity over ecological sustainability (Edens and Haynes 1982). Subsistence farmers may
value sustainability and stability over productivity. Tradeoffs also occur across agroecosystem
levels. A regional project may emphasize production at the expense of farm level stability.
There has been very little quantitative analysis of the trade-offs between agroecosystem
properties according to Conway (1991).

Stability and sustainability are by definition measured over time. Trend analyses of
productivity, equity, and autonomy also require us to measure and analyze these properties over
time. The optimal time frame suitable for monitoring systems varies. Some properties and
potential problems are best studied over a time frame of 5 to 25 years, such as short-term
changes in productivity or equity, loss of soil nutrients, pest and disease problems, and rapid soil
erosion (Lynam and Herdt 1989; Harrington 1991). Other factors require a longer time

line—from 20 to 100 years or more. The sustainability of petrochemical-based agriculture,

39
desertification, salinization, and early changes in climate and atmospheric composition are
examples of this class (Harrington 1991). It's conceivable that very long time frames, from 100
to 1000 years, might be needed to investigate issues like long-term climate change, or the loss of
genetic diversity (Harrington 1991).

Edens (1985) describes labor productivity and yield per unit of land area as two of the
most seductive quantitative criteria for evaluating agricultural performance. Many others are
possible—goods and services per unit of input or per unit of cost, costs such as tons of soil lost or
pounds of phosphorus leaked from the physical agroecosystem. Still, there are valid reasons for
evaluating agroecosystems on the basis of their labor and land productivity, not the least of
which is because they are common measures and so allow comparison with a great many
systems. An alternative agroecosystem that cannot match our present system in terms of total
yields and yields per acre would not be considered sustainable by those who embrace the food-
sufficiency approach to sustainability (Douglas 1985), nor would those alternative practices be
adopted widely (NRC 1989). A third reason is that there is a growing body of evidence, some of
which will be summarized later in this chapter, that alternative agroecosystems can achieve the
yields, and in some instances the labor productivity, of conventional farming systems. If
alternative systems can secure the benefits of present techniques while avoiding many of the
costs, then based on rational criteria, they should be adopted.

Measurement of Sustainability

There are a number of quantitative and non-quantitative methods that can be used to A
measure sustainability. Trend analysis of yields or other outputs of interest over time can be
conducted from field to regional or national levels. However, this method may not detect
problems of sustainability. Productivity grth from higher input levels, for example, could

mask declining resource quality (Harrington 1991).

40

Lynam and Herdt (1989) propose total factor productivity (TFP) as the appropriate
measure of sustainability at the cropping system or farming system level. They define TFP as
the total value of system outputs over one time period divided by the total value of inputs to the
system for the same period (Lynam and Herdt 1989). They present TFP as an economic
measure, yet it appears well suited for use with energy units. This method is primarily a measure
of efficiency; it cannot distinguish between productivity changes due to technology, input levels,
or resource quality, nor does it address the demand for system outputs. It is focused on the plot
or farm level, and it would be extremely difficult to use at a regional level (Lynam and Herdt
1989; Harrington 1991).

Direct estimation of the contribution of different factors to yield can also be used to
estimate changes in sustainability. This approach Can be powerful, as it explicitly measures
trends in state and control variables, it controls for land type changes, and changes in input
levels; and it identifies positive and negative factors affecting yields. This information can then
be integrated into models for assessing the near future. It is extremely data intensive, and
difficult to apply to complex farming systems. Like the other methods, it doesn't address
Synergistic effects directly. It also interprets sustainability in terms of efficiency, not system
resilience. Methods for measuring sustainability depend on accurate long-term records not just
for productivity, but for weather and other potential sources of shocks, such as agricultural
markets, pest problems, and many more. It is hardly surprising that few studies of sustainability
as resilience have been done, and that techniques for conducting such studies are lacking
(Conway 1991; Harrington 1991).

TFP, using energy as the measurement unit, will be combined with directional
measurement and direct estimation techniques for which sufficient information is available, to
compare the relative sustainability of conventional and organic agroecosystems. Energy analysis

and its strengths and weaknesses will be presented in the following section.

41
The Use of Energy Analysis in the Comparison of Agroecosystems

The agroecosystem hierarchy rests upon its base of biological and ecological processes.
These processes require continuous inputs of external energy, and essential nutrients that can
come from internal recycling or from external stocks. Our agroecosystems, then, rely on
continuous inputs of energy and material nutrient flows and cycles. It follows that analyses of
energy use are necessary, though certainly not sufficient, to understand our agroecosystems.

Energy analysis is an excellent tool used in conjunction with moderate reductionism.
Agricultural inputs, outputs, and flows and processes both internal and external to a given
agroecosystem can all be characterized in energy units. A whole system approach can be used
because common units are used, allowing system and subsystem efficiencies at each level to be
compared.

Energy efficiency studies consider both direct energy inputs and the amount of fossil
fuel embodied in the other inputs as well. This approach owes much to systems theory (Doyle
1990). Use of systems theory has shifted from an emphasis on unique optimization approaches
to identifying sets of solutions that are efficient according to particular economic, technical, or
social criteria. Considerations of biological efficiency have just as much relevance in evaluating
agricultural systems as ones of economic efficiency (Doyle 1990).

In practice, energy studies tend to focus on one of three levels in the agroecosytem
hierarchy. They examine either the national and international level, the farm level, or the plant
or animal level. A brief summary of literature concentrating on national/intemational level will
be presented, followed by a discusion of farm and organism level studies.

Energy analysis at the national level offers several benefits. It can reveal the energy
requirements of each process within complex production systems using a standard accounting
procedure. Energy analysis in this sense can be thought of as a form of technology assessment,

which also shows us the possibilities for energy conservation (Smil, Nachman, and Long 1983;

42
Stanhill 1984)). It allows governments and industry to plan for the consequences of different
scenarios of energy availability and price (Stout 1990; Stanhill 1984), and it can form an integral
part of larger cost-benefit or other economic studies (Smil, Nachman, and Long 1983). It can
answer the question of how energy can substitute for or be replaced by other factors of
production, and can show what forms of energy can be and are substituted for one another (Stout
1990).

Analyses of the US. food system, including all operations from farm fields to kitchen
tables, show that it consumes aproximately 16.5% of the country's energy: 2.9% in production,
4.8% for processing, 1.7% for distribution and transportation, and 7.1% for food preparation and
rural living (Stout, Butler, and Gavett, 1984). These figures agree well with those reported in
Edens and Haynes (1982), and Koenig and Edens (1976). These figures reveal that far from
being a relatively small factor in our national energy budget, our tetal agroecosystem consumes
about one-sixth of the US. energy pie. To say that the US. food system requires "only" three
percent of our national energy is akin to saying that we all buy our food at the farm gate. We do
not. We depend on our food processing and distribution system to eat, and to feed others, and '
will continue to do so.

Agriculture produces energy as well, of course, and many agricultural products can be
converted into fuels. The increase in oil prices brought about in part by the Organization of
Petroleum Exporting Countries (OPEC) oil embargo prompted interest in a variety of projects to
transorm agricultural biomass to fuel. Despite initial enthusiasm for such projects, studies have
shown that in the US. only the production of methanol from wood has the petemiei to supply
significant quantities of liquid fuel for multi-state or national markets without disrupting food,
feed, and export markets (Blobaum 1984; Smil, Nachman, and Long 1983; Stout 1990). This is
not to denigrate the considerable actual and potential use of biomass for energy production on a

local basis, where it can enjoy an energetic and economic advantage over alternatives (Stout

43
1990). However, barring Significant or even radical technological advances in energy production
or consumption technologies (e.g. vastly improved energy storage technology, room-
temperature superconducters, safe and efficient fusion power), energy conservation has the
potential to make by far the most cost-effective contribution to farm and non-farm energy
supplies (Stout 1990).
Labor Analysis as a Necessary Component of an Agricultural Energy Analysis

It is necessary to study energy and labor flows jointly, for they are inextricably
intertwined in agroecosystems. In the post-Second World War period conventional farmers
substituted energy, and capital in the form of equipment, for labor (Buttel and Gertler 1982;
Stanhill 1984). Stanhill (1984) says that the longest and most homogenous series of energy
statistics available for any national agricultural system is probably that for France. Studies based
on this data show that roughly 21,500 Meal of energy were consumed for every man-year of
agricultural labor leaving French farms between 1945 and 1960. This rate more than doubled
from 1965 to 1970. The rate of increase slowed between 1970 and 1975, a period of rapidly
rising oil costs (Stanhill 1984).

Similar transformations took place in the United States between 1940 and 1970. Over
this period the fossil energy to labor substitution ratio was over 63,000 Meal per man-year
(Stanhill 1984).

Most studies have shown that organic farms use more labor per unit of output than
conventional farms (Pimentel et a1 1983; Klepper et a1, 1977; NRC 1989). This is in keeping
with economic research, which has found that energy and labor appear to be substitutes, with

elasticities ranging from 0.48 to 3.80, depending on the country and the industry (Tietenberg

44
1988)”. Thus, as energy inputs such as synthetic fertilizers and pesticides are withdrawn, it is to
be expected in most cases that additional labor will be needed to replace that energy. Organic
farmers may be substituting labor for fossil fuel inputs.

Conventional farmers may be reluctant to adopt organic or low-extemal input systems if
they cannot supply or obtain any additional labor needed. For these reasons, in addition to those
discussed earlier in this chapter, the labor productivity of the organic farm will be compared to
that of county farms, to determine if in fact a difference can be found.

Irreversibile Changes

There are significant technical and economic constraints to reversing the undesirable
aspects of industrialized agroecosystems at the national and international level. The loss of
genetic material due to the displacement of many native open-pollinated crop varieties by a few
hybrid crops cannot be reversed if native varieties are not grown or maintained. This represents
a technical constraint to reversibility (Edens and Haynes 1982). Investments in expensive and
specialized equipment cannot be reversed or prematurely depreciated by producers without

suffering unacceptable losses—they are constrained by economic factors (Edens and Haynes

 

4

The elasticity of substitution between two factors of production, X and Y, is defined as the ratio
of the percentage change in the factor ratio to the percentage change in their relative prices, P,
and P .

Y

.A'_,;
X

A
a:

P
P

'<|>< «IN

.51
P

X

In general, elasticities of substitution greater than one indicate that substitution is relatively easy
(Tietenberg 1988 p. 293).

5

Most production studies have found capital and labor to be strong substitutes as well (Tietenberg
1988)

45
1982). Similarly, the emigration of workers from rural to urban areas following the Second
World War may impose a irreversible economic and social impediment to an expansion of
agricultural labor markets. The enormous technical, economic, and social inertia of regional and
national agroecosystems means that change requires significant forces to reverse or redirect these
systems, acting over time spans of at least one or two decades (Axinn 1988; Edens and Haynes
1982). A lack of planning over periods longer than a decade, in particular systems-level
planning, is one more factor impeding rational decision making and resource allocations (Edens
and Haynes 1982; Buttel and Gertler 1982).
Farm-Level Energy and Labor Analyses

In most energy and labor analyses conducted at the farm level, energy inputs and outputs
into the whole-farm system and subsystems are measured, and the efficiency of farm production,
labor use, and energy transformations are reported (Dobbs et al 1988). In these studies the farm
and its subsystems are treated somewhat like "black boxes." Theses studies emphasize the
relationships between inputs and outputs, and subsystems, and often disregard the physical,
chemical, and biological transformations and processes themselves. The studies reported by
Klepperet et a1 1977; Lockeretz et al 1978; Pimentel et al 1983; and Axinn and Axinn 1983
appear to fall into this group.

Pimentel et al (1983) examined the energy and labor efficiency of organic and
conventional farms growing corn, wheat, potatoes, and apples. The study was based on previous
field work done in Iowa for other studies, and no primary data were collected. The crops were
chosen to represent a range of input needs. The energy production ratio, used to compare the
energy efficiency of the two farming methods, was the ratio of the caloric potential energy of the
output to kcal of inputs. Labor productivity was defined as kilograms of output per man-hour.

It was assumed there were no effective organic means of controlling insects and plant

pathogens of potatoes and apples. This led logically to the result that crop losses would be

46
severe, and to the conclusion that organic methods were ten to ninety percent less energy
efficient than conventional means for the two crops (Pimentel et a1 1983). However, as pointed
out by Edens and Haynes (1982), Harwood (1985), and Carruthers et al (1986), there is a great
difference between an "organic" farming system created primarily by withdrawing chemical
inputs from an agroecosystem and replacing them with additional tillage, and one created by
completely restructuring an agroecosystem to replace plant and animal diversity at several levels
of the agroecosytem hierarchy over time and space.

Based on the study's asumptions, organic techniques of growing wheat and corn were
shown to be twenty-nine to seventy percent more energy efficient than conventional methods.
Labor productivity was lower for all four crops when using organic methods, ranging from
twenty-two to ninety-five percent below conventional methods. The authors stressed that the use
of energy, crop yield, and labor data from unrelated studies was a major limitation of the report,
and recommended field studies to investigate their results (Pimentel et al 1983).

Klepper et a1 (1977) studied fourteen matched pairs of organic and conventional Corn
Belt farms in 1974 and 1975. The organic farms were large-scale, mechanized farms that
differed from the conventional farms in the use of synthetic fertilizers and pesticides. All farms
in the study raised both livestock and field crops. The organic farms were selected by word of
mouth, and represented a judgement sample of case studies. Conventional farms were matched
to the organic farms on the basis of soil types, farm size, and livestock inventories. All the
conventional farmers were "top managers", as judged by local Agricultural Stabilization and
Conservation Service (ASCS) personnel, to avoid biasing the results towards the organic
farmers. The researchers stated that the matching procedure was largely qualitative, with
considerable room for differences between matched farms (Klepper et a1 1977).

Among the measures used to gauge the relative performance of the farms in Klepper's

study were the energy intensity of crop production (measured in British Thermal Units (BTUs)

47
per dollar of crop output, BTUs per acre of cropland, and BTUs per bushel of output), labor
requirements per acre and per $1,000 of crop out, and crop yields per acre. The authors stated
their results were preliminary and essentially qualitative. Measured both in British Thermal
Units (BTUs) per dollar of crop output, or in BTUs used per acre of cropland, the conventional
farms were over twice as energy intensive as the organic farms. In addition, corn raised by the
conventional group consumed from 2.7 to 2.8 times as much energy per bushel as organic corn
(Klepper et a1 1977).

For soybeans, one year the conventional group was 1.5 times more energy intensive than
the organic group; the next year, because of higher conventional yields, organic soybeans
required roughly 1.2 times more energy per bushel than conventional soybeans. In research
based on the same data, Lockeretz et al (1978) found no significant differences between organic
and conventional soybean and corn yields.

The organic farms in this study required about 3 percent more labor per acre, and
aproximately 11 percent more labor per $1,000 of crop output. The difference was greater when
expressed in labor input per dollar of crop output because the organic farms had fewer acres in
high value crops such as corn and soybeans (Klepper et al 1977).

Dobbs et a1 (1991) compared a conventional and an alternative farms in east-central
South Dakota. Most of the alternative farm's cropland qulifies as organic under criteria used in
South Dakota and neighboring states.

Corn and soybean yield data and soil samples were collected from random field samples,
and yield and soil test data were analyzed statistically by using years as replications. Differences
between corn and soybean yields were not statistically significant, (p > 0.05). This agrees with
Lockeretz et a1 (1978), which also found no significant differences between organic and

conventional corn and soybean yields.

48

The alternative farm required 58% more labor than the conventional farm (Dobbs et al
1991). No reasons for the higher labor requirements were given.

Conventional farming was more profitable on average for the conventional farmer in this
study when organic premiums were ignored, and for a variety of premium scenarios as well.
Corn and soybeans averaged 83% of the conventional farmer's land crop, as compared with 49%
of the alternative farm's acreage, the primary reason for the income discrepancy (Dobbs et a1
1991). Case studies underway for farms in other regions may give different results. A
whole-farm economic analysis based on experiment station trials at SDSU's Northeast
Experiment Station showed that alternative systems are more competitive than did the case study
covered here. Small grains make up a larger proportion of conventional farms' acreage in the
experiment station study, and so it appears that under current federal farm programs, the greater
the role of small grains in a conventional system, the more economically competitive alternative
systems are likely to be (Dobbs et al 1991).

Chou (1993) examined low-input and conventionl farming systems in terms of their
energy and economic sustainability. He compared data gathered for the Rodale Farming System
Trial from two low-input systems—one cash grain system and one with animals—and one
conventional system, which used petrochemical based fertilizers and pesticides. He found that
both of the low-input systems required one-half of the nonrenewable energy required by the
conventional system. Food and biomass energy production were highest in the low-input animal
system, while the low-input cash grain system showed the greatest stability of energy
productivity and net income, defined as the inverse of the coefficient of variation of the relevant
variable (Chou 1993).

Chou (1993) determined that the energy productivity of the two low-iput systems,
measured as calories produced per unit of nonrenewable energy input, was significantly higher

than conventional energy productivity. However, net returns above variable costs were

49
significantly higher for the conventional system. This was attributed primarily to the lower
fertilization and pest control costs on the conventional system (Chou 1993).
Energy Analyses of Individual Organisms and Soil Ecology

Research on lower levels of the agroecosystem hierarchy focuses on individual plots and
organisms, and on soil ecology. This is not to say that such research is intrinsically any less
wholistic or systems-based than research on higher levels—soil ecology is no less complex than
forest or watershed ecology. Such approaches are in keeping with the philosophy of moderate
reductionism advocated by Bunge (1977) and adopted in this paper. Certain emergent properties
will only be understood if studied at these levels. Reganold, Elliot, and Unger (1987); Patten
(1982); Coleman, Cole, and Elliot (1984); and Hendrix et al (1986) are a few examples of this
type of study.

Solar energy is usually not included in energy budgets, or is mentioned briefly, and then
set aside. It seems to have most often been treated as a constant or given factor. Research in the
physiological ecology of crops suggests a more complicated role. Early studies of
photosynthesis tended to be based on the concept of multiple limiting factors, as proposed by F.
Blackman in the early 19005, in which plants respond to increased inputs of only the most
limiting factor until another factor becomes limiting (Hall, 1990). More recent studies show that
photosynthesis is often limited by multiple and simultaneous plant and environmental factors
(Van Caemmerer and Farquhar, 1984; Hall, 1990).

Increases in productivity through plant breeding in many field crops have been achieved
by increasing the harvest index—the ratio of seed yield to total biomass—and there has been little
or no increase in photosynthetic efficiency (Gifford, 1986; Hall, 1990). In fact, Mitchell (1984)
reported that the photosynthetic rate of wheat leaves has fallen during its domestication and
breeding. Wild relatives of wheat, sorghum, coton, and pearl millet all have higher maximum

light-saturated CO2 exchange per leaf area than modern cultivars (Mitchell 1984).

50

Several studies have shown large differences in photosysnthesis between soybean
varieties, but only one study related the differences to diferences in yield. Similar results were
found for sugarcane yield and photosynthesis. Eagles (1984) writes that this decrease in the
photosynthetic rate for wheat has been compensated for by an increase in flag leaf area, so
photosynthesis per flag leaf has risen considerably. This indicates an important relationship
between yield and leaf size. Studies suggest that total leaf area available for light interception
may be a more important determinanat of yield than the photosynthetic activity of the area
(Eagles 1984).

The net conversion rates by intensively managed crops of phetesjmihetieaflm
radiation to chemical energy in the form of carbohydrates falls in a range of 2.1-3 .4 percent
(Hall, 1990.) Pimentel (1980) states that com, one of the more efficient plants, converts about
1.2 percent of inselaiien into biomass, and aproximately .4 percent into grain.

The largest single pathway in terrestrial ecosystems is usually the detritus pathway. That
is, more energy is captured and flows through detritus systems than through primary and
secondary producers. Its mass is in the same range or larger than plant biomass in virtually all
terrestrial ecosystems, if humus is regarded as detritus (Reiners 1983). This means
understanding detritus and soil systems is crucial to understanding energy flows in
agroecosystems.

Coleman et al (1984) state that a major pulse of CO2 into the atmosphere, between 1850
and 1890, was recorded by changes in carbon isotope concentrations in bristle-cone pines. This
was prior to major outputs from combustion of coal and petroleum, and was almost certainly due
to the decomposition of soil organic matter (SOM) as prairie lands were first cleared and plowed
around the world. They estimate storage of carbon in SOM at four times that of the living biota

or the present CO2 content of the atmosphere.

51

Hendrix et al (1986), studying detritus food webs, found that no-tillage appears to
increase the importance of fungi relative to bacteria as primary decomposers, and thus as the
resource base for the detritus food web. No-till soils are usually physically and chemically
stratified, with more nutrients closer to surface.

Plowing creates conditions favorable to bacteria-based food webs, composed of
disturbance-adapted organisms with high metabolic rates. This is associated with faster
decomposition of organic matter and greater nutrient mobility than in no-tillage systems. There
are also distinct seasonal variations in detritus food webs, based on substrate quality and ambient
temperature and moisture conditions (Hendrix et al 1986).

Reiners (1983) states that the apportionment of energy flow to different pathways under
different disturbance patterrns is a fundamental question. Because of the size of the detritus
pathway, the status of detritus following disturbance is therefore one of the most important
. indices of disturbance severity and recovery potential. In general, he concludes that detritus
mass decreases as a function of disturbance frequency. Ecosystem quality can deteriorate, be
maintained, or even improve with increasing frequency of disturbance. He cites some humid
pasture lands as definitely improving under disturbance (grazing), though he suggests it will
maximize at a particular frequency, and decline if disturbed more often Reiners (1983).

Elliot et a1 (1984) found that the mineralization of N, P, and other nutrients through
microbial primary and secondary production and consumption influences energy flow in at least
two ways. It controls the influx of energy by regulating primary production through the
availability of limiting nutrients, and, it controls decomposition rates as nutrient availability
interacts with substrate quality.

Because of the high production efficiencies of some of these forms, especially protozoa,

food chains longer than the usual four or five links are possible. The interactions of these life

52
forms has been shown to enhance nutrient uptake and plant yield from 30% to 100% in
microcosm experiments.

Some studies have shown that grazers enhanced plant growth more in bacterial than in
fungal systems. Considerable quantities of soluble organic carbon are released into soil by plant
roots in at least some agroecosystems. Theses inputs may be as high as 20% of total plant dry
matter or 40% of carbon translocated to the roots. Carbon losses may occur from lysis of root
cell walls rather than actual exudation. Microorganisms usually have higher densities near roots
than in root-free soils, clustering for access to the organic compounds resulting from root
exudation. This phenomenon has been demonstrated for bacteria, fungi, and protozoa.
Microflora compete with primary producers for mineralized nutrients, particularly in the
rhizosphere. The authors hypothesize that plant exudates stimulate bacterial production.
Producers immobilize N and other nutrients, including sources unavailable to the plant root. The
increase in producers stimulates grazing, which increases mineralization, taken up by the plant
root. The result is that plants effectively increase their sphere of nutrient uptake compared to ,
regular root activity (Elliot et a1 1984).

In early stages of decomposition, particularly if the material has a wide C:N ratio, any
exogenous N will be immobilized until enough respiration has occurred to bring ratios down to
about 20:1. When N fertilizers are added to crops, photosynthesis and carbon immobilization
usually increase, but fertilization can also lead to increased SOM decomposition with
concomitant release of C02, due to the creation of C:N ratios more favorable for decomposition
(Rosswall 1981). Phosphorous cycles in the soil seem to follow immobilization and
mineralization processes similar to those discussed for N, though P becomes immobilized in
stable and occluded inorganic forms more readily than N.

Studies have shown very different amounts of nitrifiers [NIL+ to NO,‘] and denitrifiers

[N03' to N2 and H20] in no—till compared to conventional till. These trends showed a 2 to 20 fold

53
increase in nitrifiers and a 3 to 43 fold increase in denitrifiers in no—till compared to plowed
fields. The authors think there may be some long-term benefits in terms of mineral N
availability and timing under no—till, possibly as a result of better "managemen " of microbial
populations, in addition to other advantages of no-till, such as maintaining SOM. Improved
management of soil microbial populations will lead to more cost-effective, efficient agriculture.

Coleman et a1 (1984) state that in general there is high variability in the types and
amounts of organisms colonizing decomposing material, that is due to a considerable stochastic
element that has not been fully appreciated. Rosswall (1981) points out that soil bacteria show
very rapid fluctuations in numbers over just a few days, especially after rainfall.

In a study of the long-term effects of organic and conventional farming on soil quality,
Reganold et a1. (1987) compared a farm managed without inorganic fertilizers since 1909 with a
conventional farm that had been using recommended rates of synthetic fertilizers and pesticides
since the 19503. The organically farmed soil had significantly higher organic matter content,
thicker topsoil depth, and lower soil erosion than the conventionally farmed soil. The
organically farmed soil also had significantly higher microbial biomass, significantly higher
polysaccharide content (they serve as active binding agents in soil agregate formation, and help
stabilize agregates), and it had a significantly lower modulus of rupture (an index related to
surface hardness, and so to seedling emergence). Lockeretz et a1 (1981) found that that water
erosion, based on rotation effects alone, was about two-thirds of the erosion on the conventional
farms. Water erosion on the organic farm studied by Reganold et al was almost one-quarter of
the conventional rate. Dobbs et al (1991) found that soil organic matter was significantly higher

on the organic farm as well.

CHAPTER FOUR
RESEARCH APPROACH

This chapter will describe the research approaches used in this study. The assumptions
on which the study rests will be explained, along with data gathering and analysis techniques.
- Selection of the Organic Farm

The organic farm was selected from a population of organic farms within a one county
radius of Ingham County. Conversations with members of the Michigan Agricultural
Stewardship Association, Ingham County Cooperative Extension (CES) personnel, and Michigan
State University (MSU) researchers led to a meeting with the organic farmer chosen. At this first
meeting the goals of the research study, data and time requirements, and confidentiality of the
results were discussed. The organic farmer selected was chosen because his farm is a mixed-
enterprise dairy and cash grain operation, the farm is relatively close to the university, the farmer
is very knowledgeable about organic farming methods, and perhaps most importantly, he is
willing to work with the researcher. '

Use of a Composite Conventional Farming System

The decision to compare an actual organic farm with a composite conventional farming
system was based on several considerations. It proved difficult to locate a suitable conventional
dairy/cash grain farmer willing or able to work within the time constraints of the researcher. It
was felt that a composite conventional farming system would allow a closer match to the size
and scale of the organic farm. Insofar as the organic farm chosen is representative of a class of

organic farms, use of a composite conventional system allows comparison of organic methods

54

55
with a variety of conventional alternatives by changing the assumptions defining the
conventional system.
System Boundaries

The organic farm's legal boundaries are defined as the boundaries of the physical
agroecosystem. Flows of energy and materials across these boundaries are considered as imports
or exports of the organic farm agroecosystem.

The physical components of the farming system are divided into subsystems. Energy,
labor, and material inputs and outputs are allocated to subsystems. The organic farm is defined
as having a crop subsystem, an animal subsystem, a pasture subsystem, and a natural
enviromnent subsystem. Transfers between subsystems are traced to analyze labor and energy
sources, flows, and sinks, in order to compare them to corresponding flows on conventional
farms. See Figure 2.X in Chapter 2 for a representation of the organic farm agroecosystem.

The crop subsystem consists of those farm areas on which the farmer grows crops for
sale off-farm, for animal feed, or for nutrient capture and cycling purposes. Inputs of interest to
the crop subsystem include the farmer's labor, manure, seed, farm machinery, and diesel fuel.

The animal subsystem is composed of all animals raised on the farm for commercial
purposes—dairy cows and replacements. Approximately 60 chickens are also raised for egg
production, but were not included in the study. The animal subsystem includes the farm
buildings and machinery dedicated to the animals, and inputs to and outputs from the animals.
Feed, electricity, and machinery and equipment are principal inputs to the animal subsystem.

The pasture subsystem is made up of the farm areas used for permanent pasture systems,
and does not include cropland used to graze dairy cattle or to raise fodder.

The natural environment subsystem contains the areas of the farm populated by non-
commercial trees, shrubs, forbs, and grasses, as well as the areas populated by natural means,

and not by direct human intervention. It includes vegetated fence rows, tree corridors, the creek

56
flowing through the property and the area bordering it, and other areas populated as described
above.

The farm household subsystem encompasses the farm family, the farmhouse, and the
barns and storage areas, which are located within approximately 100 meters of the farmhouse.

Data Collection Methods

Data describing the organic farm were collected from a number of sources. Published
soil surveys and topographical maps (SCS 1979, USGS 1979) were consulted for information on
the farm's soils and topography. Much of the remaining information was collected from personal
interviews with the farmer and his wife during farm visits.

Farm visits and interviews provided detailed information about crop rotations, input
levels, crOp and animal production levels, and management methods. The farmer also recorded
information on crop and animal inputs and outputs on prepared forms, and reviewed these forms
with the researcher, at which time additional information was gathered and clarifications were

made. Data were gathered at the field and farm levels, and then converted on a per-hectare basis.

The organic farmer has conducted on-farm research projects and comparisons under the
auspices of a program of the American Farmland Trust and the Michigan Agricultural
Stewardship Association (AFT 1992; AFT 1991). Data from these studies were analyzed and
also served to verify information collected during this study.

Information about conventional dairy and cash grain farms in Ingham County was
gathered from county, state, and national records. Crop and milk production data were collected
from Michigan Agricultural Statistics, the US. Census of Agriculture, and the Dairy Herd
Improvement Association (DHIA). The Sycamore Creek Watershed Plan provided data on
typical farming practices and rotations in the county. The Ingham County Cooperative

Extension Service (CES) provided data on dairy farming practices in the county as well.

57
Calculation of direct and indirect energy inputs and outputs

Inputs to farms and farm subsystems were converted to units of kilocalories using
formulas and values from a variety of publications (Pimental, 1980; Smil, Nachman, and Long
11, 1983; Lockeretz, 1977; Stout, 1990; Stanhill, 1984; Gillespie and Klemme, 1991; Nott et al,
1991; and others as cited). The energy values of different materials cited in the literature are
usually average values that depend on assumptions about variables such as the extraction,
manufacturing, transportation, and application methods used. The primary criteria used to select
values for this study were that the values are representative of south-central Michigan, and
consistent between authors.

The general approach taken, consistent with the literature, was to include the average
direct and primary indirect energy costs of producing and transporting an input onto a farm. The
direct energy costs of anhydrous ammonia, for example, include the energy consumed during the
manufacture, storage, and transportation of anhydrous ammonia (direct costs), as well as the
energy costs for the extraction and production of the feedstocks for the manufacturing process,
and the costs of generating the energy needed for the fertilizer production process (primary
indirect costs). Secondary indirect costs, such as the costs of producing the energy extraction
and generation equipment, were not included. Energy consumed by the farm family to maintain
their home, including personal transportation, was not included in this analysis.

Internal and External Energy Resources

All inputs to farm enterprises are considered as coming from either external or internal
sources. The farm system boundaries discussed earlier in the chapter are used to make this
determination. The principal internal resources for the organic and conventional farming
systems are animal manure and seeds. The seed for wheat production on conventional systems is

assumed to come from internal sources, so as to avoid biasing the comparison against

58

conventional systems. For this reason, conventional wheat producers relying on off-farm seed
could have lower energy output to input ratios than given in this study.
Fertilizers and Manure

The embodied energy of commercial fertilizers was calculated from values in the
literature, and includes the energy needed to process raw material feedstocks, and to manufacture
and transport the finished product. An embodied energy value for dairy manure was calculated
on the basis of data and assumptions concerning its nutrient content, and by assigning an energy
content equivalent to that of a comparable mix of synthetic fertilizers (after Smil, Nachman, and
Long, 1983; Stout, 1990). The values for the nutrient content of dairy manure were derived from
the literature (Stout, 1990) and county dairy manure analyses (CES, 1993). (Table ). Values
were determined for fresh manure because the 1988 Northern U.S. Dairy Farm Survey found that
daily hauling of manure to fields was the most common method of manure handling in Michigan
(MSU-AES 1990). The calculation for the energy content of the fresh dairy manure agrees very
closely with the average energy of dairy manure calculated in Stout (1990), taking into account

assumptions on the amount of nitrogen in fresh manure.

59

Table 4.1 The Nutrient Content and Embodied Energy of Dairy Manure as a Fertilizer

  

 
 

ENERGY VALUE OF DAIRY
FRESH (23% MANURE AS A FERTILIZER
(KCAL/KG OF FRESH

 
  
    
  

 

 

Ii Nitrogen, Total

 

 

Nitrogen, Available

 

Phosphorous (P205), Total

| Phosphorous (P205), Available 0.16% 19

Potassium (K20), Total 0.92%
Potassi (K2), Available 0.69% __ 22 . _j

 

__ __W __ -_ _. _ y
i TOTAL ENERGY CONTENT 57
l (“W :W- ._ __ - L - -

 

Table 4.2 The Embodied Energy of Commercial Fertilizers (from Lockeretz, 1980)

I F ERTILIZERS Kilocalories per Kilogram?
. __,__:_:--_-:-_-W°1final/K8) .
Anhydrous Ammonia 12000 i
M Urea

Ammonium Nitrate
iii Superphosphate

   

 

ii Triple Superphosphate
II Potassium Sulfate

 

 

One-half of the energy "cost" of manure spread on fields was allocated to the respective
cropping systems. The entire value was not allocated, because the organic farmer does not rely
completely on manure for nutrient inputs, nor would he import comparable quantities of manure

or synthetic fertilizers if he sold his dairy herd. In a similar fashion, one-half on the energy cost

60
of Spreading manure was allocated to the appropriate crop systems, and the other half was
considered to be a cost of operating a dairy herd. These method were chosen after discussing
them with the farmer, and reflect most accurately how and why he uses manure.

The fertilizing practices of at least some conventional dairy farmers in the county also
support this method. Having calibrated their manure Spreaders and tested their manure, these
dairy farmers first apply manure, and then applyd synthetic fertilizers to bring their nutrient
applications up to the levels recommended in their soil tests (CES, 1993). The chief value of the
manure was its nutrientcontent, and without it they would have applied an equivalent amount of
synthetic fertilizers. At the same time, they are obligated to dispose of their dairy manure in one
manner or another.

Pesticides

The organic farmer used no synthetic or naturally derived pesticides during the four
years studied. Conventional farmers in the county used a number of different herbicides during
the same period (CES 1992). Because the embodied energy values of all the individual
pesticides used are not available, average values for the production, formulation, packaging, and

transportation of herbicides were used (Pimental 1980).

Table 4.3 The Embodied Energy of Selected Herbicides (Pimental, 1980)

HERBICIDES Kilocalories per Kilogram Actual
Ingredient (Kcal/Kg)

 

   

 

 

 

 

 

Fonofos 99910
Metolachlor 99910 I]
Cyanizine + Atrazine 88150
Dimethoate 99910
Chlorpyrifos 99910

 

 

 

61
Fuel
All traction on the organic farm is supplied by diesel fuel consuming equipment. Fuel
consumption was calculated from consumption rates given in extension and university enterprise
budgets and energy audits (Helsel and Oguntunde, 1981; Griffith and Parsons, 1983; Siemens,
Griffith, and Parsons 1985). The fuel consumption for conventional farms was based on these
same values, and on standard and typical tillage and cultivation practices for the crop in question

as described in the Sycamore Creek Watershed Plan and the aforementioned enterprise budgets.

Table 4.4 Fuel Consumption for Conventional Farms (Lockeretz, p. 128; Stout, p.223)

 

 

 

 

 

 

 

FUEL UNITS KCAL/UNIT PRODUCTION TOTAL
INPUTS

[Diesel Liters 9235 2179 l 1414

"Electricity Kilowatt Hours (kwh) 859 2004 2863 II

 

 

Farm Machinery

The energy embodied in farm machinery and its consumption by different crop systems
was determined in the following manner. The average amount of energy per kilogram required
to manufacture and maintain a farm machine was taken from the literature (Chou, 1993;
Doering, 1980). The kilograms of farm machinery consumed per hectare was estimated from the
. weight of the machinery needed for the operation, the average useful life of the machinery, and
the time required for a given operation.

The organic farmer gave the size and type of machinery used in his operations during
interviews, and values for a similar conventional operation were derived from Wisconsin
enterprise budgets for four-row crop enterprises and other literature sources (Chou, 1993;

Gillespie and Klemme, 1991a and 1991b; Scott and Krummel, 1980; Fuller et a1, 1992). A list of

62
machinery used, their weights, useful lifetimes, and the time required for a given field operation
are given in Table 4.5.

Seeds

The value of seeds is directly related to their ability to produce a future crop of a certain
quality. Their importanceto a farming system far exceeds their embodied energy. They are
better considered as triggering devices, for which a small energy input can lead to energy outputs
several orders of magnitude higher. For this reason the energy value of seeds is best determined
from the energy needed to produce seed crops, rather than from the enthalpy of the seed itself.
Unfortunately, this data is not always available.

Various sources were used to arrive at values for the embodied energy content of seeds
used in crop production (Table 4.6). Heichel (1980, in Pimental, 1980), is one of the few sources
of information on the energy required to produce, process, and distribute crop seeds. However,
the embodied energy values he gives for some small grain seeds were equal to or less than values
given for the output energy or enthalpy of the grain in other papers in the handbook, which
makes no sense. For this study the seed energy of these small grains was estimated as the
enthalpy of the grain plus ten percent.

The embodied energy content of hairy vetch seed was taken from values determined for
alfalfa seed in Heichel, (1980, p. 31). He presents data linking seed costs with embodied energy
content, and as the market costs of hairy vetch and alfalfa seed are roughly comparable, the

alfalfa seed value was used.

63

 

 

 

 

 

 

 

 

 

 

 

 

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8: 8.... 88 8: 2... .35.. 5:3. m .. 85.. 5......

 

 

 

 

 

 

 

......=8. .8... 2.3

 

65

Table 4.6 The Embodied Energy Content of Seeds Used in Crop Production (Heichel

 

 

 

 

 

 

1980)
F SEED KILOCALORIES PER 1.
i KILOGRAM (KCAL/KG) g
rCorn 24806 !
{Soybeans 7584
[Winter Wheat 3630
l Alfalfa 43620
Rye 3340 E
Hairy Vetch 43620 l
.. _ _ _ 4918 *

 

The organic farmer supplied much of the seed he needed for grain and cover crops from
previous harvests. For these crops the seed energy was treated as an energy cost for the
enterprise, generated from internal resources.

Labor Inputs

Labor inputs for the organic farming system were calculated from information obtained
in interviews with the farmer, and are presented in the following chapter on results. One hour
per acre of labor overhead was allocated to each organic crop enterprise to allow for a direct
comparison with labor values from Wisconsin crop enterprise budgets.

Several different values for labor inputs to conventional crop and dairy systems were
calculated for comparative purposes. Michigan crop and livestock enterprise budgets values
were used to calculate one value (Nott et al, 1992; Nott, 1991). Crop and dairy enterprise
regression formulas for Michigan farms were used to generate another value (Nott et al, 1992;
Nott, 1991). Wisconsin crop enterprise budget figures were used to determine a third value for
crop enterprises (Gillespie and Klemme, 1991a and 1991b). Michigan Telefarm project data was

used to generate a value for labor inputs to the animal portion of a dairy system (Not, 1991).

66
Farm Outputs
Crop yields for the organic farm are the farmer's estimates, based on his recollection,
farm records, and the records of on-farm research studies (AFT, 1992; AFT, 1991) Figures for
milk production on the organic farm are from dairy cooperative records. Yields for conventional
farms were taken from Michigan Agricultural Statistics for the years studied. The caloric
content or enthalpy of the outputs was calculated from crop and dairy yields and the average

energy content of the output studied.

Table 4.7 Average Energy Contents of Farm Outputs

 

 

 

 

 

 

[ENERGY KCAL/KG SOURCE
OUTPUTS

Corn grain 3550 (Odum, 1984 in Stanhill, pp.24-51)
Soybeans 4021 (Pimental, 1980)

Wheat 3300 (Pimental, 1980)

Alfalfa Hay 2713 (Pimental, 1980)

Milk, Fluid .703 (Kaffka, 1984, for 3.5% Holstein milk)

 

 

 

 

 

Standardizing Yields for Soil Types

A common problem faced by agricultural researchers is the comparison of productivity
data for crops grown on soils of varying fertility. It is suggested that crop yields can be
presented as a percentage of the potential yield of the soil, thus allowing a direct comparison of
relative crop production. For the purposes of this study the potential yield or productivity of a
particular soil type is defined as the yield of a given crop possible on a particular soil type under
a high level of management, as listed in the SCS soil survey of Ingham County (SCS 1979).

Using this method, for example, we find that the potential yield for corn grain grown on
Adrian muck (Ad) is 95 bushels/acre. The potential corn grain yield on Aubbeenaubbee-Capac

sandy loam, 0 to 3 percent slope, (AnA) is 145 bushels/acre. A yield of 90 bu/acre on Ad soil

67
thus represents 95 percent of the potential yield of the soil, while a yield of 120 bu/acre on AnA
soil represents 83 percent of the potential yield of the soil. It is argued that higher percentages of
the potential yield of a soil represent more intensive management of the soil resource.

This method can be applied in any situation where the soil types and the potential yield
for the necessary crops are known, and allows at least a first order comparison between
qualitatively distinct soils. It can also be used on a patchwork of soils, such as a farm, if the
relative proportion of each soil type in the area of interest is known. This method will be used to

compare the organic farm and Ingham County crop yields in the following chapter.

CHAPTER FIVE
RESULTS

The results of comparisons of crop and dairy yields, energy inputs and outputs, and labor
flows are presented in this chapter. The results will be discussed and interpretations will be
presented. Crop and dairy yields will be considered first, followed by results of the energy flow
analyses. Labor flows will be the third and final area of the study examined.

Crop and Dairy Yields

The average crop yields and milk production data for the organic farm, together with
Michigan and Ingham County average yields, are given in Table 5.1. The same information is
presented in graphical form by individual enterprises in Figures 5.1-5.5.

The table and figures show that the organic farm crop yields were lower than state and
county averages for corn, soybeans, and winter wheat. While perhaps not readily apparent from
the figure, organic alfalfa yields were also lower than the Michigan average.

Two reasons are advanced to explain some of the difference between soybean yields on
the organic farm, and state and county average yields. The organic soybeans are grown for
soymilk and tofu production, and the variety grown for this purpose has been demonstrated to
yield less than soybeans grown for feed and oil (anonymous, 1993). The second reason for lower
soybean yields on the organic farm is that they are grown in 38-inch rows for greater ease of
mechanical cultivation, compared to the more typical 30-inch rows on conventional farms,
resulting in lower plant populations and production.

A Student's t-test statistical comparison of the organic yields with the state and county

averages showed that, for all the crops studied, the organic yields were not equal to the state or

68

 

 

69

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

Table 5.1. Selected Crop Yields for Organic and Conventional Farming Systems from
1989-1992.
" ’ ” l

Crop Yields, In kglha and as a percent of potential yield

CORN ORGANIC ORGANIC MICHIGAN INGHAM INGHAM COUNTY ll
kglha 96 of Potential Yield k COUNTYMG % of Potential Yield

1989 5166 65% 7093 7582 110% II

1990 5136 69% 7218 7564 1 10% l

1991 4712 59% 6904 7338 107%

1 992 5649 83% 6591 6534 95%

sov ORGANIC ORGANIC MICHIGAN INGHAM INGHAM COUNTY
kglha % of Potential Yield kglha COUNTY kglhl % of Potential Yield

1989 1681 64% 2421 2892 130%

1990 1749 70% 2556 2697 122%

1991 2421 106% 2556 3141 142%

1992 1076 43% 2219 2522 114%

WINTER ORGANIC ORGANIC % of MICHIGAN INGHAM INGHAM at of

WHEAT kglha Potential Yield kw COUNTY KGIHA Potential Yield

1989 2354 70% 3565 3443 97%

1990 0 - 3699 3975 1 1 1%

1991 0 - 2892 2609 73%

1992 3363 66% 3766 3739 105%

ALFALFA ORGANIC ORGANIC MICHIGAN
kilha 96 of Potential Yield it“! .

1 989 3965 75% 3660

1990 3558 90% 3965

1991 3965 101% 3965

1 992 3558 95% 4066

MILK ORGANIC Not available MICHIGAN INGRAM
kglcow Mow COUNTY kjleow

1989 6777 - 6801 6777 -

1 990 7748 - 6900 6858 -

1991 6669 - 6991 6967 -

1992 6740 - 7088 7058

 

7O

CORN YIELDS, 1989-1992

 

 

 

 

<

E

0

x

d

_i

E

>-

1989 1990 1991 1992

1 __ I

i I Organic 4 Michigan Averages E} Ingham County Averages i
1

Figure 5 .1 Com Yields From 1989 to 1992 for Organic and Conventional Farming Systems
SOYBEAN YIELDS, 1989-1992

<

E

0

x

d

.1

E

>.

 

1989 1990 1991 1992

 

1

1 I Organic 2 Michigan Average 13 Ingham County Average ‘

 

Figure 5.2 Soybean Yields form 1989 to 1992 for Organic and Conventional Farming
Systems

YIELD, KGIHA

7]

WINTER WHEAT YIELDS, 1989-1992

 

2500 1 7

 
    

.- a N
0 0| 0
O O O
O O O
1 ‘4“

1

0|
0
O

    

o 1 ., 1 7 fl 1 , .
1989 1990 1991 1992

 

1 I Organic 1 Michigan Average 1:1 Ingham County Average 1
#1

 

Figure 5.3 Winter Wheat Yields from 1989 to 1992 for Organic and Conventional Farming

YIELD, KGIHA

Systems

ALFALFA YIELDS, 1989-1992

  
 
  

4000‘
3500 8 ,

6)
O
O
O

.t—LNN
OUIOUI
000°
000°

0|

0

O O
1

1989 1990 1991 1992

I Organic Farm ‘ Michigan Average

 

Figure 5.4 Alfalfa Yields from 1989 to 1992 for Organic and Conventional Farming

Systems

72

MILK YIELDS, 1989-1992

 

YIELD, KGICOW-YEAR

 

1 989 1990 1991 1 992

I Organic '9 Michigan Average Ingham County 1
Average 1

Figure 5.5 Milk Yields from 1989 to 1992 for Organic and Conventional Farming Systems

 

county averages, but were in fact lower (p <.05). A potentially significant limitation of this test
is that the data used to calculate Michigan and Ingham County averages were not available, and
so the actual variance and standard deviations of the county and state samples were unavailable.
Instead, the variance and standard deviation of the state and county averages were used, leading
to much lower values for both statistics. It could be that alfalfa yields on the organic farm would
be found to be equal to the state average if the true sample variance and standard deviation were
available. There is little doubt that corn, wheat, and soybean yields on the organic farm were

significantly lower than the state and county averages.

73

These results do not support Hypothesis 2, which stated that the organic farm crop yields
would equal Michigan averages. They instead support an alternative hypothesis that organic
crop yields are lower than both Michigan and Ingham County averages. It is illuminating at this
point to examine the yield results as a percent of potential yield.

Table 5.1 shows crop yields as a percent of potential yield for Ingham County and the
organic farm. Potential yield figures are unavailable for the state as a whole. The results
indicate that county average yields for corn grain between 1989 to 1990 were near or above 100
percent of the potential yield, implying intensive management of the soil. An alternative
explanation is that farmers in Ingham County plant corn preferentially on higher quality soils,
meaning that the county potential yield for corn, based on all county soils, is an underestimate.
County potential yield figures are based on SCS data from 1979 and earlier, which means as well
that figures for the estimated yields possible under high levels of management, on which the
potential yield figures are based, cannot take into account yield increases due to crop varieties
developed after 1979.

Ingham County average soybean yields, expressed as a percent of the potential yield,
were even higher. They ranged from a low of 1 14 percent of the potential county average yield
in 1992 to a high of 142 percent in 1991. The author suggests that these figures represent
indirect evidence for the preferential planting of soybean crops on better quality soils, and/or the
use of higher-yielding soybean varieties compared to those available in 1979.

Because figures on hay production are not collected at the county level, data on alfalfa
hay yields for 1991 and 1992 from three conventional Ingham County dairy farms were gathered
from the county extension office for the purposes of discussion. All three farms participate in
the Sycamore Creek Watershed Project, and from the researcher's point of view were selected
essentially at random. A county agricultural agent characterized farm management for all three

as above average or better (Jack Knoreck, personal communication). Actual yields ranged from

74
4 to 6 tons/acre. Alfalfa hay yields as a percent of the potential yield for their soils ranged from
56 to 86 percent, averaging 71 percent. Organic alfalfa yields as percent of potential yield for
the particular soils for the same two years were 101 percent and 95 percent, respectively. The
organic farm alfalfa yields as a percent of potential yield were higher than the respective values
for corn, soybeans, or wheat, suggesting the organic farming system may enjoy a competitive
advantage for alfalfa relative to other crops.

Milk production per cow on the organic farm was found tO be equal to the state and
county averages. It was not expected that milk yields on the organic farm would differ from
those on conventional farms, and this appears to be the case. This supports Hypotheses 3, which
proposed that milk yields from organic farms will equal Michigan averages.

Energy Inputs, Outputs, and Flows

In this section external and internal inputs to individual organic and conventional crop
systems and rotations are compared, as are their outputs and the ratio of crop outputs to inputs.
The share of energy inputs coming from specific categories is examined, and differences
between the two farming systems are presented and interpreted. The flow of crop outputs on the
organic farm is also discussed briefly.

Solar Energy Inputs

Modern, input-intensive agriculture is still a process of collecting and concentrating
solar energy. Insolation, or incoming solar radiation, to both cropping systems was estimated at
8.34E+09 kcal/ha for corn and soybeans (l May-31 Oct)6, 9.97E+09 kcal/ha for winter wheat (1
Oct-31 July) and at a yearly total of 1.26E+10 kcal/ha for alfalfa (after Stout, 1990; Smil,

Nachman, and Long, 1983). These figures are based on radiation incident on a horizontal

 

6

Although the growing season in south-central Michigan does not extend to the end of October,
farmers nonetheless rely on solar energy to dry corn and soybean crops in the field, and may
leave crops in the field much later than October 31.

75
collecting surface, and so are almost certainly underestimates.’ This input is well over 1000
times all other energy required by conventional com, the most energy demanding crop in this
study. Seen in this light, human-controlled energy inputs to cropping systems take on the
appearance of control inputs, relatively small yet influential inputs, meant to assist in the
management of much larger flows.
Energy Inputs and Outputs for Individual Crops

Non-solar energy inputs to conventional corn crops were approximately 4.5 million kcal
per hectare, 80 percent greater than inputs to organic corn of 2.5 million kcal per hectare. Tables
5.2 and 5.3 shows energy inputs and outputs for the conventional and organic farming systems.
Figures 5.6 and 5.7 show energy inputs, external inputs, and outputs to individual crop
enterprises, as well as the ratio of crop energy outputs to inputs.

Inputs to organic corn would be even lower, but energy costs of growing a rye/hairy
vetch cover crop prior to corn were allocated as a fertilization cost to the organic corn crop.
Given that the organic farmer does not grow corn without having plowed down a legume to
supply nitrogen (evinced by his decision not to plant corn following a failed hairy vetch crop), it
was felt that the cost of growing the corn must include the costs of supplying the necessary
nitrogen as well. The organic farmer does plant corn following alfalfa plowdowns, but the
alfalfa is raised for forage, and is typically grown as a four year stand. The farmer takes
advantage of the nitrogen fixed by alfalfa, but he relies on hairy vetch to supply nutrients for

corn on an annual basis.

 

7

This is because the maximum amount of solar energy is captured by collecting surfaces (such as
leaves) perpendicular to the angle of incidence of solar radiation. Leaves, by hanging at a
variety of angles, can maximize solar energy capture for a greater part of the day.

76

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

Table 5.2. Energy Inputs and Outputs by Enterprise on 3 Conventional Versus an Organic
Farm for Corn and Soybeans
ENERGY I CORN SOYBEAN SOYBEAN
ORGANIC CONVENTIONAL ORGANIC CONVENTIONAL
INPUTS (kcal/ha) kcal/ha kcal/ha kcal/ha kcal/ha
lnsolation 8.34E+09 8.34E+09 8.34E+09 8.34E+09
Machinery 105,360 138,157 113,616 93,908
Fuel (diesel) 769,936 1,049,800 809,374 614,224
Natural Gas 0 0
Fertilizer 30,213 2,057,863 0 289,627
PesticIdes 0 887,989 0 223,967
Seeds 417,055 417,055 510,030 510,030
Other 0 0 0
Postharvest 0 0 0
Subsidy from Other 1,183,292 0
Crops
All External Energy 1,426,865 4,004,874! 1,433,020 1,731 ,756
Inputs
All lntemal Energy 1,079,992 545,990 0 0
Inputs
All Inputs minus 2,505,857 4,550,864 1,433,020 1,731,756
lnsolation
OUTPUTS
Crop Yields (kcallha) 18,066,578 24,633,411 7,201,157 9,774,573
OUTPUT! 7.21 5.41 k 5.03 5.64
INPUT
OUTPUT! 12.66 5.03 5.64

 

EXTERNAL INPUT

 

6.15 1

 

 

 

77

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

Table 5.3. Energy Inputs and Outputs by Enterprise on a Conventional Versus an Organic
Farm for Alfalfa and WInter Wheat
ENERGY ALFALFA ALFALFA I WINTER WHEAT WINTER WHEAT
_ ORGANIC CONVENTIONAL ORGANIC CONVENTIONAL
INPUTS kcallha kcallha kcal/ha kcal/ha
Insolation 1 .26E+10 1.26E+10 9.97E+09 9.97E+09
Machinery 49,659 64,888 95,886 118,121
Fuel 330,315 397,498 760,338 854,714
Natural Gas 0 0 0
Fertilization 0 26,900 547,866 1 ,492,231
Pesticides 0 503,927 0 0
Seeds 183,342 183,342 610,300 406,867
Other 0 0 0 0
Postharvest 0 0 0 0
Subsidy from 0 0 0 0
Other Crops
All External 563,317 1,176,555 856,224 1,904,263
Energy Inputs
All Internal Ene , 0 0 1,158,166 967,670
All Inputs minus 563,317 1,176,555 2,014,390 2,871,933
Insolation
OUTPUTS
Crop Yields 22,740,574 23,372,188 8,411,050 11,572,053
(kcal/ha)
OUTPUT! 40.37 19.86 4.18 4.03
INPUT RATIO
OUTPUT! 40.37 19.86 9.82 6.08
EXTERNAL INPUT 4
RATIO

 

 

 

 

 

 

78

Due to the costs of the rye/hairy vetch cover crop, the distribution of input costs among
machinery, diesel fuel, fertilization, and seed costs are similar for the organic and conventional
corn crops. Figures 5.8 and 5.9 display the distribution of energy inputs by categories for
selected crops for the two farming systems. Pesticide costs for the conventional corn made up
almost 20 percent of the energy input, an input avoided in the organic system, while fertilization
costs for the conventional corn system were almost 70 percent higher than for the organic corn
crop. Interestingly, diesel fuel and machinery energy inputs were 36 percent and 31 percent
higher for the conventional system compared to the organic inputs. This was due to the costs of
spreading manure from the conventional dairy operation on the corn acreage. Mechanical weed
control increased the machinery and fuel inputs to the organic com, a technique not needed by
the conventional system.

The ratio of corn energy output to all non-solar inputs was 7.21 (to 1) for organic corn
compared to 5.41 for conventional com. If the ratio of energy outputs to external energy inputs
is considered, the ratio of 12.66 for organic corn is more than double that for conventional corn,
6.15. lntemal sources supplied 43 percent of the organic corn inputs (including internal energy
from the rye/hairy vetch cover crop), but made up only 12 percent of the inputs to conventional
corn.

An unexpected result Of this study is that under the study's assumptions conventional
soybean crops produced more output energy per unit of energy input, 5.64, than the
corresponding organic soybean crops, at 5.03. Over the four years covered in the study soybean
yields and energy outputs for the conventional soybeans were nearly 36 percent higher than the
organic soybean outputs, more than compensating for the extra inputs of fertilizer and herbicides
the conventional soybeans required. The organic soybeans required inputs of approximately 1.4
million kcal; the conventional soybeans had 1.7 million kcal of inputs, 2] percent higher than the

organic soybeans. No internal inputs were applied to soybeans under either of the farming

79

ENERGY OUTPUTS AND INPUTS. WITH 0" RATIOS

5.41

 

 

 

 

 

 

 

 

 

 

 

:15 25,000,000 40.37_l9.86
D .
g g 15,000,000
< To
:2 3 10,000,000
I-
8 0

Corn Soybeans Alfalfa Winter

Wheat
1 I

I Organic Inputs

I Organic Outputs [11 Conventional

Inputs

1] Conventional
Outputs

 

Figure 5.6 Energy Outputs and Inputs, with Output/Input Ratios, for Organic and
Conventional Farming Systems.

6.15

 

 

 

ENERGY OUTPUTS AND EXTERNAL INPUTS. WITH 0" RATIOS

 

 

 

 

 

 

1,15 25,000,000 1
D
g 20,000,000 ~—12'“~ 3
g g 15,000,000 I 564
< 711 ' ‘ 1 .
f’.’ 3 10,000,000 - - , 5°03 1
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8 ° ‘
Corn Soybeans

 

 

 

 

 

 

 

 

40.37__19-86
1—- 6.08—
_ 9.82 }‘
Alfalfa Winter
Wheat

 

I Organic Inputs.

External

‘

I Organic Outputs 11]] Conventional
Inputs, External

1: Conventional
Outputs

Figure 5.7 Energy Outputs and External Inputs, with Output/Extemal Input Ratios, for
Organic and Conventional Farming Systems.

80
systems, so the ratio of soybean energy outputs to external energy inputs is the same as the ratio
of soybean outputs to all inputs.

The organic soybeans required almost 32 percent more diesel fuel energy, for
mechanical cultivation. The conventional soybeans needed modest amounts of synthetic
fertilizers and herbicides (0.51 million kcal), equal to the energy requirements of the seed.
Winter wheat grown on the organic farm consumed just over 2 million kcal in inputs. Winter
wheat grown under the assumptions of the composite conventional system required 2.9 million
kcal of inputs, almost 43 percent more than organically grown wheat. Diesel fuel and seed
inputs were the largest inputs for the organic wheat. The seeding rate for organic wheat was 50
percent higher than it was for conventional wheat. Because conventional wheat yields were
almost 38 percent higher than the organic yields, winter wheat output energy per unit of input
was virtually identical for the two systems—4.03 for the conventional wheat as Opposed to 4.18
for organic wheat. The ratio of wheat energy outputs to external energy inputs favored the
organic system. At 9.82, the ratio is almost 63 percent higher than the value of 6.08 for
conventional wheat. It is important to note that these figures are based on the assumption that
conventional farmers supply wheat seed from their own crops. If this is not the case, energy
output per unit of external energy for the conventional system would drop by 20 percent.

The principal inputs to the organic wheat were diesel fuel, seeds, and fertilizer in the
form of manure. The conventional wheat required both manure and synthetic fertilizer, diesel
fuel, seeds, and pesticides as primary inputs. Over 5 7 percent of the organic wheat inputs came
from internal sources, including seed and manure. The corresponding figure for conventional

wheat was just under 34 percent, also in the form of manure and seed.

81

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Organically grown alfalfa consumed less than half the energy inputs of conventional
alfalfa, 0.56 million kcal compared to 1.18 million kcal. Though no internal energy inputs were
used to grow alfalfa, it was the most energy frugal crop for both farming systems. Because of
this, and because alfalfa produces high levels of plant matter, the output to input ratios were
quite high. It was estimated that the organic system produced just over 40 kcal of energy output
for each kcal of input. The corresponding figure for conventionally grown alfalfa was 19.86.
Diesel fuel for harvesting alfalfa hay was the largest input for the organic farm (59 percent), and
pesticides were the largest energy input to conventional alfalfa (43 percent).

For the four individual crops studied, energy inputs per hectare were higher for
conventionally grown crops, ranging from 20 percent over the organic inputs for soybeans to
almost 110 percent over inputs to organic alfalfa. Conventional outputs were also higher for
each of the four crops. Conventional alfalfa outputs were not quite 3 percent greater than
organic alfalfa outputs. The differences between energy outputs for the other three crops were
quite similar, with organic outputs between 37 and 35 percent less than conventional yields. The
ratio Of energy outputs to all non-solar inputs, and to external inputs, provide some measure of
which farming system produces the most energy per unit of input. Organic alfalfa was the most
productive by far, with an output to input ratio of over 40 to 1. Conventional alfalfa was next, at
almost 20 to 1. Organic corn returned over 7 kcal for every kcal of inputs, and produced over
12.5 kcals for every kcal of external energy inputs. Output to input ratios for the conventional
crops not yet mentioned were in a range of 4 to 1 up to 6 to 1. Conventional soybeans were
more energy productive than were organic soybeans, while organic and conventional winter
wheat total energy productivity were quite close at just over 4 to 1. For corn, alfalfa, and wheat,
the ratios of organic energy outputs to external energy inputs were 61 to more than 100 percent

higher than the respective conventional ratios.

84

While it seems clear that several organically grown crops may produce more energy per
unit of energy input than their conventional counterparts, the exceptions cast doubt on
Hypothesis 1, that organic farms produce more energy outputs per unit of energy inputs than
conventional farming systems. An examination of several organic crop rotations with a typical
conventional rotation provide a clearer picture.

According to the Sycamore Creek Watershed Plan, a five year rotation of com-com-
corn-soybeans-winter wheat is both common and typical for conventional farmers in the
watershed (SCS 1992). Three organic rotations, typical of the organic farmer studied, were
compared to the conventional rotation. The rotations and their inputs and outputs are shown
Table 5.4. The figures shown are five year totals.

It can be seen from an inspection of Figure 5.10 that the three organic rotations are
virtually identical in the relative distribution of energy inputs by category. Machinery and
fertilization costs are within a few percentage points of each other for each rotation. Seed inputs
make up the largest input for each rotation, and are close to 50 percent for each organic rotation.
If the embodied energy of hairy vetch seed could be shown to be lower, the relative size of inputs
from seed in the organic rotations would drop significantly. Fuel costs across the rotations are
within a percentage point of each other, and are all about 38 percent of the total inputs.

The distribution of energy inputs for the conventional system are qualitatively different
from the organic rotations. They are similar only in that machinery is a relatively small part of
inputs. In contrast to organic systems, fertilization inputs including manure and synthetic
fertilizers make up the largest single input, just under 44 percent. Diesel fuel is a relatively
smaller portion of the conventional energy budget, accounting for 25 percent of inputs.

Pesticides and seed costs make up the balance of the conventional inputs.

85

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

Table 5.4 Five Year Totals for Energy Input On Organic and Conventional Farm
INPUTS, kcal/ha ROTATION 1 ROTATION 2 ROTATION 3 ROTATION
‘ ORGANIC ORGANIC ORGANIC 4
CONVEN-
TIONAL
Corn-Soy- Soy-Winter Soy-Rye- Corn-Corn-
Rye 8. Hairy Wheat-Rye Rye 8. Hairy Corn-Soy-
Vetch 8. Hairy Vetch-Corn Wheat
Vetch-
Corn-Oat-
Rye 8. Hairy
__ Vetch-Corn _ _
Machinery 680,036 625,327 612,285 626,501
Fuel 4,568,473 4,212,336 4,112,332 4,618,338
Natural Gas 0 0 0 0
Electricity 0 0 0 0
Fertilization 465,363 946,805 807,756 7,955,446
Pesticides 0 0 0 2887934
Seeds 5,669,514 5,397,679 4,798,956 2,168,062
Other 0 0 0 0
Postharvest 0 0 0 0
Transport 0 0 0 0
Subtotal - 11,777,423 11,182,147 10,331,329 18,256,281
Insolation
External 7,725,218 6,450,830 6,493,948 15,650,641
Energy
Subtotal
OUTPUTS,
kcauha
Crop Yields 74,632,948 69,946,103 62,563,841 95,246,859
Output! 6.34 6.26 6.06 5.22
Input
Output! 9.66 10.84 9.63 6.09
External Input

 

 

 

 

 

 

 

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Over a five year period the conventional rotation produces from 28 to 52 percent
more energy output than do the organic rotations, despite the fact that the organic soy-winter
wheat-rye+hairy vetch-com-oats-rye+hairy vetch-corn includes four of the five crops grown
in the conventional rotation. These figures are consistent with the output results from the
individual crops.

The three organic rotations all have energy output to input ratios between 6.06 and
6.34 to 1. The conventional rotation has a ratio of 5.22 to 1, about 18 percent less than the
organic rotations. The difference is more pronounced when energy output per input unit of
external energy is considered. Two of the organic rotations are almost identical, at about 9.6
to l. The third is 10.8 to 1. The corresponding value for the conventional system is 6.09 to 1.
The organic rotations produce significantly more energy per input of external energy, and
appear to produce almost 20 percent more energy per kcal of energy input than the
conventional rotation. These figures support Hypothesis 1. It appears that organic crop
systems do produce more energy per input unit than the conventional system.

Energy Flows

Flows of energy and materials in the form of farm machinery, diesel fuel, seeds, and
synthetic fertilizers are the principal off-farm inputs for the cropping systems studied. These
flows, including their size, have been discussed for particular crops and crop rotations earlier
in this chapter.

Flows of energy off-farm for the systems studied are in the form of milk and farm
products. Although the organic farmer grows more than enough corn to feed his dairy cattle,
beginning in 1990, organic corn is fed to the herd for about five or six months over the winter,
while as much com as possible is sold for organic premiums. Commercial corn is then used
for the dairy ration. In 1990 about two-thirds of the organic corn was sold off-farm. The

remainder was fed to the dairy herd, providing about 80 percent of the corn they consumed.

88
Approximately one-quarter of the 1991 corn harvest was used for feed, which supplied the
dairy herd from mid-November 1991 to mid-May 1992. The remainder was sold. A similar
pattern was followed in 1992.

The organic famer followed a similar pattern with soybeans. He fed the dairy herd
soybean meal made from beans culled during processing, sold his soybeans for an organic
premium, and bought commercial soy meal for feed. The dairy ration includes about 12
percent oats, all of which is provided from farm crops. The balance is sold Off-farm. He also
sells hairy vetch and rye/hairy vetch mix seed to other farmers for use as cover crops, along
with some rye grain.

All alfalfa hay grown on the farm was fed to the dairy herd, and a very minor three
percent in additional forage was purchased. Forage and roughage contribute about 58 percent
of the total feed calories needed by dairy cattle (Oltenacu and Allen, 1980). Together with the
feed grains grown on the organic farm, approximately 80 to 90 percent of the calories
consumed by the dairy herd were grown on the organic farm.

Though similar data were unavailable for conventional dairies, farms with dairy herds
smaller than 65 cows had an average internal feed crop transfer (from crop systems to dairy
herds) of $39,731. They spent an average of $19,281 to purchase feed (Nott, 1990). This
means that 67 percent of the cost of dairy feed was met from on-farm resources. It seems
likely that the percentage of calories fed from conventional on-farm resources was at least
slightly higher, as typical purchased feed additives such as minerals, vitamins, and molasses
do not provide many calories.

Both the organic and conventional farming systems depend on the flow of nutrients
from manure back to the soil to help maintain soil fertility. Assuming a dairy cow and a
. replacement together generate 45 kg/day of manure, a dairy cow with replacement produces

about 1 million kcal per year of manure, using an embodied energy value based on fertilizer

89
replacement for fresh manure discussed in Chapter 4. This is equivalent to each cow with
replacement returning approximately 60 kg of actual available nitrogen, 27 kg actual available
phosphate, and 113 kg of actual available potash each year.

The third significant internal transfer of energy is the use of home-grown seed on the
organic farm. The organic farmer provides his own seed for wheat, oats, rye, hairy vetch, and
barley crops. Seed is a significant portion of the embodied energy inputs to these crops,
ranging from 30 to 70 percent of the total inputs of the crop. Data on the use of home-grown
seed by conventional farms in the area were unavailable.

Labor Inputs

Table 5.5 shows the results of the comparison of energy outputs per hour of labor
input. Figure 5.11 illustrates this information. It is apparent from the table and figure that the
closest match to the actual labor figures for organic corn is the data from the Wisconsin
Livestock and Cash Crop Enterprise Budgets. The Michigan labor budget and regression
figures agree well with the actual organic output to labor input figures for soybeans, though
all three are some 50 percent smaller than the Wisconsin labor budget figure. For winter
wheat the Michigan labor regression figure and the Wisconsin labor budget match. For
alfalfa, the ratio of outputs to labor for the Wisconsin labor budget figure agrees with the
organic farmer's ratio, and both are three times greater than the figures suggested by Michigan
budget and regression formulas.

Michigan Telefarrn data for hours of labor per dairy cow for dairy farms with less
than 65 dairy cows is identical to the organic farmer's estimate of 67 hours per cow per year.
This figures are slightly larger than those estimated from the Michigan budget and regression
figures for a herd of 100 cows, but less than the estimate the Michigan regression formula

gives for a herd of his size.

90

 

 

 

 

 

 

 

Table 5.5. Ratio of Energy Outputs to Labor Inputs for Organic and Conventional
Farming Systems
OUTPUTIHOUR, in kcal CORN SOY ALFALFA WINTER
WHEAT
_—_—— fi—flw
OUTPUT/HOUR, ORGANIC j 2,480,000 1,040,000_ 3,980,000 1,140,000
OUTPUT/HOUR, MI BUDGET 1,630,000 1,060,0001 909,000 1,230,000
OUTPUT/HOUR, MI REGRESSION 1,670,000 1,010,0001 803,000 1,580,000
OUTPUT/WI BUDGET 3,730,000 1,520,000 2,890,000 1,510,000

 

 

 

 

 

 

 

CROP ENERGY OUTPUTS PER LABOR HOUR

4.00E+06 .
3.50E+06 7:11 1
3.00E-I-06 1
2.50E+06 —
2.00E+06 >-

 

 

 

 

 

 

 

 

 

 

 

 

   
 

 

 

 

 

 

 

KCALIHOUR

  

 

 

 

 

 

 

 

 

   

 

 

 

1.50E+06 4 ,, '—
1.00E+06 , l _ _ , , _
5.00E+05 ‘_ , _ , 1*
0.00E+00 -*~ ' .811 » .~ .
Corn Soybeans Alfalfa Winter Wheat
1
1 I Organic Output/MI Budget D Output/MI [ll] OutputIWI Budget 1
‘ Output/Hour Hour Regression Hour Hours 1

 

Figure 5.1 1 Crop Energy Outputs per Labor Hour for an Organic and Several Conventional
Farm Labor Budgets

91

These data do not support Hypotheses 4, which states the organic farm would require
more labor per unit of output than the conventional Michigan farm average. The measure
employed to test this hypothesis was energy output per unit of labor, a measure of labor
productivity. Higher values Of labor productivity equal lower labor inputs per unit of energy
output. Energy output per unit of labor for corn and alfalfa was much higher for the organic farm
than for either of the Michigan calculations. Energy output per unit of labor for soybeans were
quite close for the three Michigan examples. For winter wheat the output of energy per labor hour
from the organic farm was lower than the other two Michigan cases. Data from Wisconsin were
used to provide another point of comparison.

These data do not provide sufficient evidence to support Hypothesis 4. In several
instances the organic farm yielded more energy per unit of labor than the two Michigan
conventional examples.

Summary

The analysis of results does not support Hypothesis 1, which stated that organic farm crop
yields would equal or exceed Michigan averages. Hypothesis 2 was supported by the results,
which showed that milk yields from the organic farm were comparable to Michigan averages.
Hypothesis 3 was supported by data that showed that organic rotations produced more energy per
unit of energy input. Hypothesis 4 is not supported by the results. Energy output from the organic
farm per unit of labor input was greater than or equal to the corresponding values from the
Michigan conventional examples for several crops.

These results, their meaning, and conclusions will be discussed in the following chapter,

and suggestions for further research will be presented.

CHAPTER SIX
CONCLUSIONS AND RECOMNIENDATIONS

A central premise of this study is that the sustainability of an agroecosystem is inversely
related to its degree of openness; that is, the more open an agroecosystem, the less sustainable it
will tend to be. This study characterized an organic farm as a relatively closed agroecosystem,
and a composite conventional farming system as a relatively open agroecosystem. Sustainability
was represented by the variables of yield per unit of land and cow, energy input per unit of crop
output, and labor inputs per unit ofcrop and cow.

An energy analysis was conducted on the two agroecosystems. Agricultural inputs,
outputs, and flows and processes internal and external to the agroecosystems were characterized in
energy units. Because common units were used, system and subsystem efficiencies at different
levels of the farm agroecosystem could be compared. This approach is grounded in systems theory
(Doyle 1990).

Two hypotheses address the relative sustainability of the two agroecosystems based on
their yields. The ratio of energy outputs to energy inputs forms the basis for another hypothesis.
The relationship between farming systems and labor productivity provide the final hypothesis.

Hypothesis 1 and Conclusions 1

Hypothesis 1, which states that the organic farm would require less energy per unit of
output than the Michigan average, was supported by the results. All the organic crops studied
were produced with lower direct and indirect energy inputs. Due to the higher yields of the
conventional farming system, the ratio of energy outputs to inputs were closer for the individual

crops studied. For corn, alfalfa, and wheat the ratio of energy output to all non-solar inputs for the

92

93
organic crops was greater than the ratio for conventional crops, ranging from more than double the
conventional ratio to just under four percent higher. Unexpectedly, conventional soybean crops
produced more output energy per unit of energy input, 5.64, than the corresponding organic
soybean crops, at 5.03. This was a result of higher conventional yields and only slightly lower
energy inputs for the organic soybeans.

However, a comparison of organic and conventional rotations reveled that organic
cropping systems do produce more energy per unit of energy input than do conventional systems.
The organic system energy output/total energy input ratio was almost 20 percent higher than that
of the conventional rotation. The organic rotations studied all yield over 50 percent more energy
output per unit of external energy input as compared to the conventional rotation.

This is due to several factors. The organic rotations all include cover crops, which
demand fewer inputs than cash crops. Fertilization in the conventional rotation consumed more
energy than the entire external energy demands of each of the organic rotations. The higher yields
Of the conventional rotation were not enough to offset the higher energy requirements. This study
shows that for three of the four crops, conventional methods required more machinery inputs. In
the case of corn and wheat, this was because the conventional system applied both manure and
fertilizer to the crops. In the case of alfalfa, machinery was required to spread fertilizers and
pesticides that were not used on the organic farm. Organic soybeans demanded more machinery
than their counterparts due to the need for multiple cultivations.

Hypothesis 2 and Conclusions

Hypothesis 2, which states that organic farm crop yields would be equivalent to Michigan
averages, was not supported by the study results. Instead, the data suggest that conventional crop
yields are higher than those of the organic farm studied.

Organic corn, soybean, and winter wheat yields averaged very close to 70 percent of those

considered possible by the SCS on the organic farm soils under high levels of management. The

94
corresponding averages for the conventional yields were close to or over 100 percent. There are at
least two possible reasons for this difference. First, the conventional figures are evidence of
preferential planting of these cash crops on the best available soils, meaning that the county
potential yield figures, based on all county soils, are underestimates. Alternatively, the difference
may be due to the fact that county potential yield figures are based on SCS data from 1979 and
earlier. This means that figures for the estimated yields possible under high levels of management
do not account for yield increases due to crop varieties developed after 1979. It is quite possible
that both of these factors play a role in the "overyield" phenomenon observed for the conventional
crop averages.

The organic farm demonstrates several of the transition effects noted by Dabbert and
Madden (1986a, 1986b), and Harwood (1985). The organic farmer studied, who undoubtedly
knows his farm better than anyone, estimates his yields using organic methods are 85 or 90
percent of those he could expect using conventional techniques. This reduction in yields caused
by the switch to an organic system is a biological transition effect. The reduction in yields may
also be due in part to a learning or knowledge effect. Lockeretz and Madden (1987) found that
organic farmers often claim the lack of information on organic methods hampers greater adoption,
as did the organic farmer who cooperated in this study. It is possible that this may reflect the
comparatively small amount of research and extension devoted to organic farming, rather than the
complexity of organic systems (Lockeretz 1991).

Hypothesis 3 and Conclusions

Hypothesis 3 states that organic farm milk production would be equal to Michigan
averages. This was supported by the results. There was no significant difference between milk
yields per cow on the organic farm and average yields per cow at the county and state level.

This is not surprising. Milk production is a function of genetic makeup and diet. The

organic dairy herd's diet is similar to that used elsewhere in the county and state. The organic

95
farmer buys breeding stock and insemination services from local suppliers, so there is no reason to
doubt that his cows are genetically similar in terms of quality to other county herds.

This hypothesis served as a "check" upon the animal systems. If milk yields had proved
dissimilar, the result would have warranted further study. Differences between the organic and
conventional herds, such as differences in herd health, may exist, but are beyond the scope of this
study.

Hypothesis 4 and Conclusions

Hypothesis 4 stated that the organic farm would require more labor per unit of output than
the Michigan average. This hypothesis was not supported by the results. The data suggest there is
no difference in the amount of labor required per unit of output between the organic farm studied
and estimates provided by three different conventional labor budgets.

Energy output for organic corn and alfalfa per labor hour were much higher than the
figures predicted by the Michigan labor budget and regression studies. Output per labor hour for
organic alfalfa was over four times the figures suggested by the Michigan studies, and a third
higher than the figure predicted from data in the Wisconsin farm crop budgets. Output per labor
hour for organic corn was fifty percent higher than that predicted by the Michigan studies, and
fifty percent lower than the ratio predicted by the Wisconsin farm crop budgets.

Output per labor hour for organic soybeans was within a few percentage points of the
figures based on Michigan enterprise budgets, but was almost fifty percent lower than the ratio in
the Wisconsin budgets. Organic winter wheat energy output per labor hour was 8 to 39 percent
lower than the figures predicted by the three conventional enterprise budgets.

It is difficult to determine the areas where differences in labor demands arose, because the
conventional labor enterprise budgets did not disaggregate labor requirements by categories such

as tillage, planting, and harvesting.

96

This result is quite intriguing, as a number of previous comparative studies have shown
that organic farming systems demand more labor, as farmers substitute labor in the form of
cultivation and tillage for chemical inputs. These results suggest that at least in some
circumstances low external input or chemical-free farming does not necessarily mean more labor
intensive farming.

General Conclusions

The organic farming system did prove to be a more closed system. Direct and indirect
energy inputs to the organic agroecosystem were far lower than energy inputs to conventional
farming systems. Does this mean that the organic farming system is more sustainable; that is, can
the organic farming system maintain productivity in the face of significant disturbance better than
the conventional agroecosystems studied? The answer depends on the nature of the disturbance.

In the transition to an organic agroecosystem, internal nutrient and energy cycles have
been reestablished that free the farm from reliance on external fertilizer and pesticide inputs. If
there is a major disturbance to input supplies or availability, including regulation or taxation, the
organic agroecosystem seems far better prepared to deal with it than the conventional farming
systems. The data also suggest that the organic agroecosystem is no more vulnerable to
disruptions of labor markets than are conventional systems. Although yields from the organic
system are lower than the conventional yields, it remains to be seen what the effects of the
disturbance of pre-existing soil ecologies by chemical inputs will be. It may be that organic
systems are able to maintain production over time far better than petrochemical-based
agroecosystems.

In short, the organic agroecosystem is more sustainable than the conventional farming
systems studied in terms of energy efficiency and independence. It is as sustainable as the
conventional systems in terms of laborefficiency. It may or not be as sustainable in terms of crop

production as the conventional systems.

97
Implications

Despite predictions of soaring energy prices, made at the height of the Organization of
Petroleum Exporting Countries (OPEC) oil embargo, and their dire consequences on agriculture,
petroleum prices adjusted for inflation are lower than they were prior to the start of the embargo.
Corrected for inflation the price of fertilizer nitrogen was at an all-time low in the European
Community in 1990 (de Wit 1990), and fertilizer nitrogen prices have not increased since then. It
may well be that the availability of agrichemicals will depend less on petroleum markets than on
govemment-imposed regulations and taxes.

Though current oil prices demonstrate the difficulty of predicting future trends based on
past and present information, it seems likely that present trends in the regulation and taxation of
farm chemicals will continue and increase. These trends are driven by forces such as public and
personal health concerns and the desire to address point and non-point source pollution problems,
among others. The Michigan Groundwater and Freshwater Protection Act, recently signed into
law, imposes fertilizer taxes and increases pesticide regulation fees. It is only one of the latest in a
series of state and federal actions aimed at reducing agricultural extemalities.

Such trends will encourage more efficient use of on and off-farm resources, including
chemicals. Because farmers tend to be price takers, they cannot pass input price increases along
to consumers. This means they must cut costs to create or maintain profit margins. If these trends
continue, yields per unit input, including energy and labor efficiency, will become an increasingly
important, albeit incomplete, measure of agricultural sustainability.

Recommendations for Future Research

A number of information needs exist at different levels of the agroecosystem hierarchy. At
the farm level, transition effects, including biological and learning effects, are poorly understood,
and yet have significant repercussions on agroecosystems. It is suggested that research into these

effects be expanded. Some possible questions are the information needed when an organic or

98
alternative system is being developed. ls more information required to adopt a new system. or for
its continued use? Does handling the information needed for an alternative or organic system
require more time, or does it also demand more management skill? Studying farm operators' skill
is quite difficult, and has been neglected.

The extent of environmental extemalities related tO agrichemical use needs to be
determined and quantified, so that more efficient economic and social policies can be determined.

As stated earlier in this study, a sustainable agriculture necessarily must address the
sustainability of social, economic, and physical systems making up an agroecosystem.
Information on the impact of different farming systems on the sustainability of rural communities
and regions is needed before the continued dis-integration of rural societies and economies
becomes irreversible, and the question becomes tragically moot.

Finally, further work is needed in the measurement and comparative analysis of
sustainability. An adequate method of measuring sustainability should be able to distinguish
between yield changes due to changes in inputs (movement along a production function), yield
changes due to technological change, and changes in yield due to changes in resource quality
(after Harrington 1991). The sustainability of our agroecosystems is a matter of increasing
importance in a world with a growing appetite for food and fiber, and little stomach for the

problems caused by conventional agriculture.

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