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Conservation tillage, chemical input and manure history

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CONSERVATION TILLAGE, CHEMICAL INPUT AND MANURE HISTORY IN
REGULATING CORN (Zea mays L.) AND SOYBEAN (Glycine max (L). Merr.)
PRODUCTION AND FATE OF NITROGEN IN SOIL

BY

Chuanguo Xu

A DISSERTATION
Submitted to
Michigan State University
in partial fulﬁllment of the requirements
for the degree of

DOCTOR OF PHILOSOPHY

Department of Crop and Soil Sciences

1994

ABSTRACT
CONSERVATION TILLAGE, CHEMICAL INPUT AND MANURE HISTORY
IN REGULATING CORN (Zea mays L.) AND SOYBEAN (Glycine max (L. ) Merr.) .
PRODUCTION AND FATE OF NITROGEN IN SOIL
By

Chuanguo Xu

The role of conservation tillage and chemical inputs on N leaching is
uncertain. This study evaluated three conservation tillage systems, as well as
chemical input, and manure application history, in relation to soil stratiﬁcation, in
regulating corn and soybean production, soil physical properties, and the fate of N
in soil. Field experiments were conducted on the Kalamazoo loam soil ('l‘ypic
Hapludalf, ﬁne loamy, mixed, mesic) at Kellogg Biological Station, Hickory Comers,
Michigan for the period 1990 to 1993. The study consisted of two manure history
treatments (with and without manure applieations from 1981 to 1989), three tillage
treatments (chisel plow (CP), no-tillage (NT) and ridge till (RT)), and two chemieal
input levels (140 kg N ha" with broadcast herbicides (HI) and no nitrogen fertilizer
application with herbicides banded (LI)). A Br tracer was used in three tillage
treatments to monitor soil solution movement in 1992 and 1993. Three chemical
leaching models were tested using soil proﬁle bromide content.

Manure application history decreased soil bulk density and increased total
porosity. The effect of manure history was to increase N mineralization resulting
higher in the soil proﬁle and to increase soil solution NO3-N, thereby increasing the

potential for NO,-N leaching. High chemical input increased com grain yield, N

concentrations in corn tissue and N uptake. Soil proﬁle and suction lysimeter data
indieated that N O3-N was leached out of the root zone soon after N fertilization.
Without N fertilization, NT and RT corn were generally more deﬁcient in nitrogen
and yielded less than CP. Soybean yields were affected by soil crusting in GP and
weed pressure in manure history. Ridge till had the highest soil solution NO3-N
concentration. Bromide placement in the row in RT resulted in less Br leaching than
CP and more Br leaching with Br placement in the midrow. The Bums equation, TFE
and MACRO models successfully predicted Br movement for RT and failed to predict
Br contents under NT and CP. This study suggests that RT had the greatest impact
on chemical leaching potential based on chemieal placement position. Using average
row and midrow values, NT had higher leaching potential than CP and RT.

Additional N fertilizer contributed to additional N leaching throughout the year.

ACKNOWLEDGNIENTS

I express my sincere appreciation to my advisor, Dr. Francis Pierce, for his
guidance, encouragement and constant friendship throughout this study, and for his
invaluable and time assistance in the preparation of this manuscript. Appreciation is
also extended to Dr. Boyd Ellis, Dr. James Crum and Dr. James B. Hart, Jr. for
serving on my the guidance committee and for their advice.

Acknowledgement is also made to Charlotte Gaye Burpee for her help in the
preparation of the manuscript. I thank Brian Long for his technical assistance on the
research. Thanks are also due to Moacir Dias for assistance in graphics preparation.

I am also grateful to the undergraduate students who assisted in this research.

I would like also to thank to Dr. Earl Erickson, who originally gave me the
opportunity to study in the United States. Without that opportunity, this dissertation
would not been possible.

I also want to thank to my wife, Yun Wang and my daughter, Yue Xu for their

consistently support me to complete this program.

TABLE OF CONTENTS

LIST OF TABLES .......................................................................... VI
LIST OF FIGURES ........................................................................ .IX
INTRODUCTION ............................................................................ .1
CHAPTER 1. Corn and Soybean Response to Manure Application,
Tillage, and Chemical Input ............................................. 16
Material and Methods ............................................................ 20
Results and Discussion ........................................................... 23
Summary and Conclusion ........................................................ 29
List of References ................................................................ 31

CHAPTER 2. Nitrate-Nitrogen in Stratiﬁed Soils under Variable Tillage,

Chemical Input, and Manure History ................................. 52

Materials and Methods ........................................................... 54

Results and Discussion ........................................................... 57

Summary and Conclusion ........................................................ 64

List of References ................................................................. 67
CHAPTER 3. Bromide Movement Related to Tillage and Positions on a Glacial

Outwash Soil .............................................................. 90

Materials and Methods ........................................................... 92

Results and Discussion ........................................................... 98

Summary and Conclusion ...................................................... 105

List of References... ......................................................... 107

SUMMARY AND CONCLUSION ..................................................... 129

IV

LIST OF TABLFS

CHAPTER 1
Table 1. Analysis of variance table ................................................... 34
Table 2. Corn grain yield (@15 .5 96) as affected by manure application

Table 3.

Table 4.

Table 5 .

Table 6.

Table 7.

Table 8.

Table 9.

history, chemical input, and tillage treatments for the period
1990 to 1993 .................................................................... 35

Corn plant population as affected by manure application history,
chemical input and tillage treatments for the period 1990 to 1993.... 36

Corn stover weight (Mg ha") at black layer as affected by manure
application history, chemical input and tillage treatments for the
period 1990 to 1993 ........................................................... 37

Nitrogen concentration of corn grain, stover at black layer,
and tissue on silking for the period 1990 to 1993 ....................... 38

Corn plant tissue N content at silking, N content of grain and
stover, and total N uptake at black layer as affected by manure
application history, chemical input and tillage treatments in 1990.. . . 4O

Corn plant tissue N content at silking, N content of grain and
stover, and total N uptake at black layer as affected by manure
application history, chemical input and tillage treatments in 1991.... 41

Corn plant tissue N content at silking, N content of grain and
stover, and total N uptake at black layer as affected by manure
application history, chemical input and tillage treatments in 1992. . .. 42

Corn plant tissue N content at silking, N content of grain and
stover, and total N uptake at black layer as affected by manure
application history, chemical input and tillage treatments in 1993.... 43

Table 10.

Table 11.

Table 12.

Table 13.

Soybean yield as affected by manure application history,
chemical input and tillage treatments for the period 1990 to 1993... 44

Soybean population as affected by manure applieation history,
chemical input and tillage treatments for the period 1990 to 1993. . . 45

Effects of tillage on bulk density, saturated hydraulic
conductivity, total porosity and pore-size distribution
of 0-7.6 cm and 7.6-15.2 cm soil depth on April 22, 1992 ............ 46

Effects of tillage and manure on bulk density, total porosity
and pore—size distribution of 0-7 .6 cm soil depth on

November 12,1993 ........................................................... 47
CHAPTER 2
Table 1. Precipitation and estimated precipitation nitrogen input in growing
season and fallow period in 1990, 1991, 1992 and 1993 .............. 69
Table 2. Stratiﬁcation index for the Ap/Bt and Bt/ C horizon boundary
in the Kalamazoo Loam soil over the period 1990 to 1993 ........... 70
CHAPTER 3
Table 1. Field measured soil physical properties used an input value for

Table 2.

Table 3.

Table 4.

Table 5 .

Table 6.

MACRO model ............................................................... 109

Comparison of Br recovery for the 0 to 80 cm depth under three
tillage treatments and two position after 288 mm cumulative

rainfall in 1993 ................................................................ 110
Com plant tissue Br concentration under three tillage treatments
in 1992 and 1993 ............................................................. 111

Comparison of ﬁeld measured and simulated values of Br
contents in 60 cm soil proﬁle of Kalamazoo loam soil ................. 112

Comparison of predicted and measured Br contents for three
simulation models for ridge till in 1992 .................................. 113

Comparison of predicted and measured Br contents for three
simulation models for ridge till in 1993 .................................. 114

VI

Table 7. Comparison of predicted and measured Br contents for three
simulation models for no-tillage and chisel plow in 1993 ............. 116

VII

LIST OF FIGURES

CHAPTER 1
Figure 1. Cumulative growing degree days after planting for the period 1990

to 1993 at Kellogg Biological Station ....................................... 48
Figure 2. Monthly rainfall for the 1990 to 1993 growing season .................. 49

Figure 3. Effects of tillage on air-ﬁlled porosity at O to 7.6 cm and 7.6 to
15.2 cm depths for the Kalamazoo loam soil sampling
on April 22, 1992 .............................................................. 50

Figure 4. Effects of manure history and tillage on air-ﬁlled porosity at 0 to
7.6 cm depth for the Kalamazoo loam soil sampling on
November 12, 1993 ........................................................... .51

CHAPTERZ

Figure 1. Illustration of soil proﬁle horizons, soil sampling depths,
soil solution sampler installation, and TDR placement for
the Kalamazoo loam soil at Hickory Comets, MI ...................... 72

Figure 2. Soil proﬁle NO,-N as affected by manure history, tillage,
and chemical input following corn for the Kalamazoo loam
soil for the June, 1990 soil sampling date ................................. 73

Figure 3. Soil proﬁle NO,-N in the spring as affected by manure history
following soybeans in the previous year for the Kalamazoo
loam soil for the period 1991 to 1993 ...................................... 74

Figure 4. Soil proﬁle NO,-N in the spring as affected by manure history

following corn in the previous year for the Kalamazoo loam soil
for the period 1991 to 1993 ................................................. 75

VIII

Figure 5. Soil proﬁle NO3-N in the fall as affected by manure history
following corn for the Kalamazoo loam soil for the period
1990 to 1993 .................................................................... 76

Figure 6. Soil proﬁle NO3-N as affected by manure history, tillage, and
chemical input following soybeans for the Kalamazoo loam
soil for the December, 1992 soil sampling date ........................... 77

Figure 7. Soil solution NO3-N in response to manure history sampled
at the Bt/C horizon contact of a Kalamazoo loam soil during
the 1991 and 1992 growing season .......................................... 78

Figure 8. Nitrogen balance (N,) for the growing season and over winter
period as affected by manure history over the period
1990 to 1993 .................................................................... 79

Figure 9. Soil proﬁle N03-N in the fall as affected by chemical input
levels history following corn for the Kalamazoo loam soil
for the period 1990 to 1993 .................................................. 80

Figure 10. Soil solution N O,-N in response to chemical input levels
sampled at the Bt/ C horizon contact of a Kalamazoo loam soil
during the 1991 and 1992 growing season ................................ 81

Figure 11. Nitrogen balance (N,) for the growing season and over winter
period as affected by chemical input levels over the period 1990
to 1993 ........................................................................... 82

Figure 12. Soil proﬁle N03-N in the spring as affected by tillage systems
following corn in the previous year for the Kalamazoo loam
soil for the period 1991 to 1993 ............................................. 83

Figure 13. Soil proﬁle N O3-N in the spring as affected by tillage systems
following soybeans in the previous year for the Kalamazoo
loam soil for the period 1991 to 1993 ...................................... 84

Figure 14. Soil proﬁle NO3-N in the fall as affected by tillage systems

following com the Kalamazoo loam soil for the period
1991 to 1993 .................................................................... 85

IX

Figure 15. Soil solution NO,-N in response to tillage systems sampled
at the Bt/C horizon contact of a Kalamazoo loam soil during
the 1991 and 1992 growing season ......................................... 86

Figure 16. Nitrogen balance (N,) for the growing season and over winter
period as affected by tillage systems over the period
1990 to 1993 ................................................................... 87

Figure 17. Soil volumetric moisture content (0) as affected by tillage
system for the 0 to 15 and 15 to 30 cm depths of a Kalamazoo
loam soil in 1991 .............................................................. 88

Figure 18. Soil volumetric moisture content (0) as affected by tillage
system for the 0 to 15 and 15 to 30 cm depths ofa Kalamazoo
loam soil in 1992 ............................................................... 89

CHAPTER3

Figure 1. Illustration of Br application in the row and midrow position
for ridge till .................................................................... 117

Figure 2. Illustration of processes and ﬂuxes in MACRO model (redraw
from Jarvis, 1991) ............................................................ 118

Figure 3. Br concentration changes with cumulative rainfall and depths
for the row Br application and row sampling in
ridge till in 1992 ............................................................... 119

Figure 4. Br concentration changes with cumulative rainfall and depths
for the midrow Br application and midrow sampling in ridge
till in 1992 ...................................................................... 120

Figure 5 . Br concentration changes with cumulative rainfall and depths
for the row Br application and midrow sampling in ridge
till in 1992 ...................................................................... 121

Figure 6. Br concentration changes with cumulative rainfall and depths
for the row Br application and midrow sampling in ridge
till in 1993 ...................................................................... 122

Figure 7. Br concentration changes with cumulative rainfall and depths
for the midrow Br application and row sampling in ridge
till in 1992 ...................................................................... 123

X

Figure 8. Br concentration changes with cumulative rainfall and depths
for the midrow Br application and row sampling in ridge
till in 1993 ...................................................................... 124

Figure 9. Br concentration changes with cumulative rainfall and depths
for row sampling in no-tillage in 1993 .................................... 125

Figure 10. Br concentration changes with cumulative rainfall and depths
for the midrow sampling in no-tillage in 1993 .......................... 126

Figure 11. Br concentration changes with cumulative rainfall and depths
for row sampling in chisel plow in 1993 ................................. 127

Figure 12. Br concentration changes with cumulative rainfall and depths
for the midrow sampling in chisel plow in 1993 ....................... 128

XI

INTRODUCTION

Every soil and water management problem, including water quality, erosion,
productivity, investment risk, international competitiveness, and long-term
sustainability, is inﬂuenced by the basic condition of the soil resource and how the
soil is managed (Karlen et al., 1990). The research need with regard to soil tillage
with chemical input is to understand how soil should be manipulated to provide

optimum conditions for each of the problems list above.

C . 1 Ill 1 C . Till

The primary purposes of tillage are to control weeds and create a favorable
soil environment for seed emergence, plant growth and crop production. As stated by
Schafer and Johnson (1982), ”Any mechanical manipulation that changes a soil
condition may be considered tillage" . Conventional tillage, is deﬁned here as
moldboard plow, with overall plowing to 20—cm depth (fall or spring), followed by
secondary tillage to 10 cm with a disc, following planting and possibly
post-emergence cultivation.

Conservation tillage systems are systems of managing crop residue on the soil

surface with minimum or no tillage. The systems are frequently referred to as stubble

2

mulching, limited tillage, reduced tillage, minimum tillage, no-tillage, and direct drill.
The goal of these systems of plant residue management is threefold: to leave enough
plant residue on the soil surface at all times for water and wind erosion control, to
reduce energy use, and to conserve soil and water (U nger and McCalla, 1980).

The evolution in tillage practices for corn has leaned strongly toward no-tillage
in recent years, due to the energy and cost factors (Olson and Sander, 1988). The
reduction in erosion and energy input for no-tillage has meant a greatly modiﬁed soil-
temperature-water-air environment compared to conventional tillage.

Chisel plowing is a tillage procedure that is accomplished by chisel points or
sweeps attached to shanks spaced from 20 to 40 cm apart that allow penetration to
depths of 15 to 30 cm (Olson and Sander, 1988). The soil is lifted and loosened in
the tillage zone with little soil turnover, leaving most of the prior crop’s residue on
the surface. The chisel plow is an excellent erosion control tool compared to the
moldboard plow (Wischmeier, 1973).

Ridge till is a soil management tool used to improve the plant root
environment. Walter at e1. (1991) summarized four ridge till advantages: 1)
increased surface drainage and warmer soil temperatures in the vicinity of the ridge,
which promotes seed germination and seedling growth; 2) elimination of fall plowing
and increased soil residue cover, which decrease soil erosion by wind and water; 3)
the use of cultivation and banded application of herbicides, which reduces the need
for chemical weed control; 4) banded fertilizer applications, in which improve yields

in both uninfected and root worm-infested plants.

Ill 1 l l C E l .

Crops respond to changes in soil water content, soil temperature, nutrient
supply, composition of the soil atmosphere, and to the strength of the soil. The
speciﬁc tillage practice employed inﬂuences all these plant growth factors, although
the effects may be different in different soils and under different weather conditions.
The speciﬁc response to a soil physical change may depend on the plants’
physiological growth stage.

Unger and McCalla (1980) summarized the role of conservation tillage on the
crop production. Grain yields were little effected by tillage practices under conditions
of adequate soil water, favorable precipitation, and good drainage, provided other
factors such as soil fertility, weed control, and plant populations were equal. Under
conditions of limited soil water and limited precipitation or irrigation, crop yields
were equal and often signiﬁcantly higher with reduced- and no—tillage systems than
with conventional tillage.

Wagger and Denton (1992) reported that no-tillage can signiﬁcantly increase
the yield of com. This yield enhancement can be attributed to the surface residue
cover minimizing soil crusting, thereby reducing runoff and improving soil water
availability. Moreover, after 5 yr there was no drawback to continuous no-tillage
corn production systems, but rather an overall yield advantage compared with no-
tillage following conventional tillage. Soybean yields during the 5 yr period were 5 %
higher with no-tillage. They suggested that continuous no-tillage should be the system

of choice on upland Piedmont soils.

4
Tyler et al. (1983) found that full-season soybean yields were unaffected by

tillage system on silty soils in western Tennessee. On heavy clay soils in the
Mississippi Blaclands Prairie region, no-tillage resulted in a 20% soybean yield
reduction compared with conventional tillage (Hairaton al. , 1984). These yield
variations illustrate the need to determine regional or loeal suitability for a given
tillage system. Joint Nebraska and Illinois studies over a 3-yr period showed slightly
higher yields with moldboard plowing than with chisel plowing (Cihacek et a1. , 1974).
Chisel plow and moldboard plow treatment gave comparable average corn grain yields
when compared over four years on ﬁve soils in Indiana (Grifﬁth et a1. , 1973).

Considerable research has demonstrated the importance of a combination of
conservation tillage and crop rotation in maintaining corn yield compared with
continuous monoculture (Adams et al., 1970; Barber, 1972; Edwards etal., 1988;
Meese et al., 1991), even though the reason is not well understood. Crop rotation in
conjunction with various tillage systems has also received attention; however, results
have been conﬂicting. Dick and Van Doren (1985) reported that rotating corn with
soybean, cat and alfalfa (Medicago sativa L) minimized the negative effects of NT on
a very poorly drained Hoytille soil. In the Appalachian Plateau region of Alabama,
Edwards et a1. (1988) found corn yield unaffected by tillage or crop rotation in two
out three years. Strip tillage or NT in conjunction with soybean in the rotation
increased corn grain yield by 12%.

Results from the few studies involving rotation of tillage systems have been

contradictory. On poorly drained soils in Ohio, com yield reductions for the second

5

and succeeding two years of no-tillage, compared with continuous fall moldboard
plowing, were alleviated when no-tillage followed conventional tillage (Triplett and
Van Doren, 1985). Shear and Moschler (1969), however, found no beneﬁt to corn
grain and stover yields from moldboard plowing in alternate years, compared with six

years of continuous no-tillage.

5.] IE' 1C '1'

The concern over elevated nitrate levels in groundwater has increased during
the past few years. Numerous studies have shown that the nitrate concentration in
groundwater in agricultural watersheds is considerably higher than in forested
watersheds (Hallberg, 1989; Juergens-Gschwin, 1989; Pionnke and Urban, 1985).
Swistock et a1. (1993) found that nitrate concentrations were signiﬁcantly higher in
wells closer to corn ﬁelds. Leaching losses of N as NO3-N, are most signiﬁcant
when fertilizer addition exceeds the crop N requirement (Roth and Fox, 1990;
Meisinger et al., 1982).

Kladivko et al. (1991) conducted a drainage research study on a Clermont silt
loam (Fine-silty, mixed, mesic Typic Glossaqalt) in Indiana. Nitrate concentration in
tile drainage water under a corn crop fertilized with 285 kg N ha" were seldom less
than 10 mg N L" and usually within the 20 to 30 mg N L’1 range, with annual losses
ranging between 18 and 70 kg N ha", depending on tile drain spacing. The
concentration of N 03- in tile drainage and the amount of NO; loss was proportional to

the amount of N fertilizer applied to a Webster silt loam (ﬁne-loamy, mised, mesic

6

Typic Haplaquoll) in Iowa (Baker and Johnson, 1981). In particular, Baker and
Johnson (1981) found that N fertilization rates of corn between 90 and 100 kg N ha"
resulted in ﬂow-weighted NO; concentrations of 20 mg N L" in tile drainage, with a
total annual loss of 27 kg N ha"; where N fertilizer rates between 240 and 250 kg ha"
resulted in ﬂow-weighted NO; concentration of 40 mg N L" and total annual N losses
of 48 kg N ha". Prunty and Montgomery (1991) found that ﬂow-weighted NO,-
concentrations from lysimeters in a Hecla loamy ﬁne sand (sandy, mixed Aquic
Haploboroll) in North Dakota were 8.6 mg N L" for low N management (95 kg N
ha" added fertilizer) and 12.3 mg N L" for high management (145 kg N ha") corn
production systems. However, the addition of 95 kg N ha" was below the maximum
economical rate of fertilizer use for yield. In many other studies with corn
production systems, the concentration of NO; in tile drainage exceeded the 10 mg N
L" limit for potable water. For example, the range of NO; concentrations in leaching
from lysimeters in Uppsala, Sweden, ranged from 10 mg N L" in clay soils to 50 mg
N L" in sandy soils (Bergstrom and Johansson, 1991). Annual N losses from
lysimeters seeded with spring barley (Hordeum vulgare L.) and fertilized with 100 kg
N ha" were 20 kg N ha" or less for clay soils, 25 and 40 kg N ha" for loamy soils,
and 65 kg N ha" for sandy soils. Rainfall and irrigation also contributed to the extent
and timing of NO; loss. In several studies, increase in N 03- concentration in tile
drainage appeared within 2 to 3 months after N was applied (Hubbard et al., 1984;
Baker and Johnson, 1981) and persisted up to 3 yr following the last application of N

fertilizer. It has been well-documented that manure applications, when applied to soil

7

in addition to normal fertilizer application, are a signiﬁeant source of excessive soil
N. Unless the N contribution of manure is accounted for, N applications to soil may
exceed crop requirements, thereby resulting in leaching losses of signiﬁcant quantities
of NO; (Roth and Fox, 1990).

Tillage has also been shown to affect N use efﬁciency and the subsequent
potential for NO; leaching. The tillage can inﬂuence macropore development,
distribution, persistence, and continuity. Conservation tillage, and especially no-
tillage, in medium- and ﬁne-textured soils facilitate the development of a stable
macropore network due to uninterrupted earthworm activity (Edwards et a1. , 1988).
The preferential water ﬂow through vertical channels created by earthworms in no-till
soils is a possible mechanism responsible for accelerated transport of chemicals
(Ehlers, 1975; Thomas and Phillips, 1979; Kanwar et al., 1985; Lee, 1985; Wagenet,
1987; Dick et a1. , 1989). Rapid leaching of chemical through macropores may cause
groundwater contamination and less availability of nutrients to plants. Beven and
Germann (1982) have discussed factors that inﬂuence the dynamics of macroporosity.
They concluded that the volume and structure of the macropore system represents a
dynamic balance between constructive and destructive processes.

In contrast, several studies have shown disagreement. When studying
Brookston soil with shrinking and swelling characteristics, Drury (1993) reported that
the increased yield and N uptake in grain resulting from the no-tillage and ridge till
reduced the amount of N 03- available for leaching. Conservation tillage also reduced

these losses somewhat, as there were lower volume of water lost and lower

8

concentrations of N O,— in tile drainage. The cracks that formed on the soil surface
were greater with the conventional tillage treatment than the conservation tillage
treatments. Therefore the conventional tillage treatment probably had more water lost
through preferential ﬂow, which would increase the relative amount of tile drainage
and decrease the relative amount of surface runoff. When studying with a Manor
loam soil in Maryland, Angle et a1. (1993) found that nitrate concentration under the
no-tillage plots were consistently lower when compared with concentrations under the
conventional-till plots. They concluded: "the use of no—tillage cultivation may reduce
the leaching of nitrates beyond the crop root zone, and suggested that no-tillage

cultivation is a true best management practice as related to both surface and

groundwater quality” .

 

Numerous tracer studies have indicated that in soils containing macropores,
both water and agricultural chemicals can move preferentially (J abro et a1. , 1994).
Preferential movement of water can allow surface-applied agricultural chemicals to
move rapidly through the root zone, thereby contributing signiﬁcantly to groundwater
contamination problems. Computer simulation models have become a useful tool in
understanding and predicting environmental problems resulting from the movement of
agricultural chemicals through soil into the groundwater (Jabro et a1. , 1994; Jarvis et
a1. 1991).

A simple chemical leaching equation, derived by Burns (1975) gives the

9
distribution of surface-applied nitrate after a given quantity of applied water has
passed through the soil proﬁle. Later on, Towner (1983) and Scotter et a1. (1993)
examined the theoretical basis of equation and derived a simpliﬁed form. However,
reports of ﬁeld tests of this model are limited.

The transfer function model, as a non-mechanistic stochastic model, was an
approach to measure the distribution of solute travel time from the soil surface to
some reference depth. Field comparisons have shown good agreement between
measured and predicted bromide concentrations (J urry et a1. , 1982), and indicate that
this model could be useful as a stochastically—based management model for solute
movement. The most important characteristic of such a model is that it attempts to
simulate spatially-variable ﬁeld processes with only a minimum of input data. But it
is not yet known whether the approach will be satisfactory in vertically non-
homogeneous soils (Addicott and Wagenet, 1985).

The deterministic MACRO model was developed by Jarvis in 1991. The
model assumes that the total porosity in each layer is divided into two components,
micropores and macropores, with a speciﬁed boundary water potential. The MACRO
model has been employed to simulate movement of conservative tracers and pesticides
in the soil water. When used to predict Br losses from corn in Hagerstown silt loam,
MACRO performed reasonablely well after calibration. The information on model
testing on different tillage systems is limited.

Presently, Interactions between tillage, manure application and chemical input

impact on N leaching have received limited attention. The effects of conservation

10

tillage systems on groundwater NO,-N concentration are still unclear.

The objectives of this study were (1) to examine the inﬂuences of various
combinations of tillage, the long-term efﬁcacy of animal manure applications, and
chemical inputs on corn and soybean production and on selected soil physical
properties; (2) to evaluate the role of conservation tillage systems, chemical inputs,
and manure history in relation to soil stratiﬁcation in regulating the fate of N in soils;
(3) using bromide as a tracer, to evaluate movement and distribution of chemicals
under ridge till, chisel plow and no-tillage; (4) to test the Burns leaching equation, the
Transfer Function Model of solute transport and the MACRO model in three tillage

and two row positions under ﬁeld and natural rainfall conditions.

LIST OF REFERENCES

Adams, W.E., H.D. Morris, and RN. Dawson. 1970. Effect of cropping
systems and nitrogen levels on corn (Zea may L.) in the Southem
Piedmont Region. Agron. J. 62:655-659.

Addiscott, T. M. and R. J. Wagenet. 1985. Concepts of solute leaching in
soils: a review of modeling approaches. J. Soil. Sci. 36:411-424.

Angle, J.S. C. M. Gross, R. L. Hill, and M.S. McIntosh. 1993. Soil nitrate
concentration under corn as affected by tillage, manure, and fertilizer
applieation. J. Environ. Qual. 22:141-147.

Baker, LL. and H.P. Johnson. 1981. Nitrate-nitrogen in tile drainage as
affected by fertilization. J. Environ. Qual. 10:519-522.

Barber, SA. 1972. Relation of weather to the inﬂuence of hay crops on
subsequent corn yields on a Chalmenrs silt loam. Agron. J. 64:8-10.

Bergstrom, L., and R. Johansson. 1991. Leaching of nitrate from monolith
lysimeters of different types of agricultural soils. J. Environ Qual.
20:801-807.

Beven, K., and P. Germann. 1982. Macropores and water ﬂow in soils.
Water Resour. Res. 18:1311—1325.

Burns, 1. G. 1974. A model for predicting the redistribution of salts applied
to fallow soils after excess rainfall or evaporation. J. Soil Sci. 25:165-
178.

Cihacek, L.J., D.L. Mulvaney, R.A. Olson, L.F. Welch, and RA. Wiese.
1974. Phosphate placement for corn in chisel and moldboard plowing
systems. Agron. J. 66:665-668.

Dick, W.A., R.J. Roseberg, E.L. McCoy, W.M. Edwards, and F. Haghiri.
1989. Surface hydrologic response of soils to no-tillage. Soil. Sci. Soc.
Am. J. 53:1520-1526.

Dick, W.A., and D.M. Van Doren, Jr. 1985. Continuous tillage and rotation

combinations effects on corn, soybean, and oat yields. Agron. J.
77 :459-465.

11

12

Drury C. F., D. J. McKenney, W.I. Findly, and JD. Gaynor. 1993.
Inﬂuence of tillage on nitrate loss in surface runoff and tile drainage.
Soil Sci. Soc. Am. J. 57:797-802.

Edwards, J.H., D.L.Thurlow, and LT. Eason. 1988. Inﬂuence of tillage and

crop rotation on yields of corn, soybean, and wheat. Agron. J. 80:76-
80.

Edwards, J.H., D.L. Thurlow, and J .T. Eason. 1988. Inﬂuence of tillage

and crop rotation on yields of corn, soybean and wheat. Agron J.
80:76-80.

Elrlers, W. 1975. Observations on earthworm channels and inﬁltration on
ﬁlled and untilled loess soil. Soil Sci. 119:242-249.

Grifﬁth, D.R., Mannering, J.V. Galloway, H.M., Parsons, 8.1). and
C.B.Richey. 1973. Effect of eight tillage-planting systems on soil
temperature, percent stand, plant growth, and yield of corn on ﬁve
Indiana soils. Agron. J. 65:321-326.

Hairaton, J.E., J.O. Sanford, J.C. Hays, and LL. Reinschmidt. 1984. Crop
yield, soil erosion, and net return from tillage systems in the
Mississippi Blacklands Prairie. J. Soil Water Conserv. 39:392-395.

Hallberg, G. R. 1989. Nitrate in groundwater in the United States. p. 35-74.

(ed.). Nitrogen management and ground water protection. Elsevier,
New York.

Hubbard, R.K., L.E. Asmussen, and H.D. Allison. 1984. Shallow
groundwater quality beneath an intensive multiple-cropping system
using center pivot irrigation. J. Environ. Qual. 13:156-161.

Jabro, Jalal D., John M. Jemoson, JR, Richard H. Fox, and Daniel D.
Fritton. 1994. predicting bromide leaching under ﬁeld conditions
using SLIM and MACRO. Soil Sci. 157:215-223.

Jarvis, N. J., L. Bergstrom, and P. E. Dik. 1991. Modeling water and solute
transport in macro-porous soil. II Chloride breakthrough under non-
steady ﬂow. J. Soil Sci. 42:71-81.

J uergens-Gschwin, S. 1989. Ground water nitrate in other countries (Europe)-
Relationships to land use patterns. p. 75-138. in R.F. Folllett (ed.).

13

Nitrogen management and ground water protection. Elsevier, New
York.

Kanwar, R.S., J.L. Baker, and J.M. Laﬂen. 1985. Nitrate movement
through the soil proﬁle in relation to tillage system and fertilizer
application method. Trans. ASAE 28:1802-1807.

Karlen, D.L., D.C. Erbach, T.C. Kaspar, T.S. Colvin, E.C. Berry, and D.R.
Timmons. 1990. Soil tilth: a review of past perception and future
needs. Soil Sci. Soc. Am. J. 54:153-161.

Kladivko, E. J., G.E. Van Scoyoc, E.J. Monke, K.M. Oates, and W. Pask.
1991. Pesticide and nutrient movement into subsurface tile drains on a
silt loam soil in Indiana. J. Environ. Qual. 20:264-270.

Lee, KB. 1985. Earthworms - Their ecology and relationships with soils and
land use. Academic Press, New York.

Meese, B.G., P.R. Carter, E.S. Oplinger, and J .W. Pendleton. 1991.
Corn/ soybean rotation effect as inﬂuenced by tillage, Nitrogen, and
hybrid/cultivar. J. Prod. Agric. 4:74-80.

Meisinger, J.J, T.H. Carski, M.A. Ays, and V.A. Bandel. 1982. Residual
nitrate nitrogen in Maryland. p.215. in Agronomy abstracts. ASA,
Madison, WI.

Olson R.A. and DH. Sander, 1988. Corn production. In Corn and corn
improvement-agronomy monograph no. 18, 3rd edition.

Pionnke, H.B. and J. B. Urban. 1985. Effect of agricultural land use on
ground-water quality in a small Pennsylvania watershed. Ground
Water 23:68-80.

Prunty, L., and B.R. Montgomery. 1991. Lysimeter study of nitrogen
fertilizer irrigation rates on quality of recharge water and corn yield.
J. Environ. Qual. 20:373-380.

Roth, L.W., and RH. Fox. 1990. Soil nitrate accumulations following
nitrogen-fertilized corn in Pennsylvania. J. Environ. Qual. 19:243-248.

Schafer, R. L. and C. E. Johnson. 1982. Changing soil condition- The soil
dynamics of tillage. In: Predicting tillage effects on soil physical
properties and processes. ASA spec. Publ. No. 44:13-27.

14

Scotter, D. R., R. E. White and J. S. Dyson. 1993. The Burns leaching
equation. J. Soil Sci. 44:25-33.

Shear, G.M., and W.W. Moschler. 1969. Continuous corn by the no-tillage
and conventional tillage methods: A six-year comparison. Agron. J.
61:524-526.

Swistock, B.R., W.E. Sharpe, and PD. Robillard. 1993. A Survey of lead,
nitrate and radon contamination of private individual water systems in
Pennsylvania. J. Environ. Health. 55:6-12.

Thomas, G.W., and R.E. Phillips. 1979. Consequences of water movement in
macropores. J. Environ. Qual. 8:149-152.

Towner, G. D. 1983. A theoretical examination of Burns’ (1975) equation
for predicting the leaching of nitrate fertilizer applied to a soil surface.
J. Agric. Sci., Camb. 100:293-298.

Triplett, G.D., and J .H. Van Doren. 1985. An overview of the Ohio
conservation tillage research. p 59-68. In F.D’Itri (ed.) A systems
approach to conservation tillage. Lewis Publ., Chelsea, MI.

Tyler, D.D., J.R. Overton, and A.Y. Chamber. 1983. Tillage effects on soil
'es, diseases, cyst nematodes, and soy bean yields. J. Soil Water
Conserv. 38:374-376.

Unger, P.W. and T. M. McCalla. 1980. Conservation tillage systems. Adv.
Agron. 33:1-57.

Wagenet, R.J. 1987. Processes inﬂuencing pesticide loss with water under
conservation tillage. p. 189-204. In T.J. Logan et al. (ed.) Effects of
conservation tillage on ground water quality: Nitrates and pesticides.
Lewis Publ. Chelsea, MI.

Wagger, M.G., and H.P. Denton. 1992. Crop and tillage rotations: Grain
yield, residue cover, and soil water. Soil Sci. Soc. Am. J. 56:1233-
1237.

Walter E. Riedell, Ralph D. Gustin, Dwayne L. Beck, and Denise G. Hanson,
1991. Westen corn rootworm damage: effect of tillage on plant
response and grain yield. Crop Sci. 31:1293-1297.

15

Wischmeier, W.H. 1973. Conservation tillage to control water erosion p. 133-
141. In Conservation tillage. Proc. Natl. Conf., Des Moines, IA. 28-30
March. Soil Conserve. Soc. Am., Ankeny, IA.

CHAPTERI

Corn and Soybean Response to Manure Application, Tillage, and Chemical Input

Conservation tillage is generally accepted as the most successful technology
currently available for reducing soil loss and runoff. Conservation tillage includes
any tillage-planting system that leaves at least 30% of the soil surface covered with
crop residue after planting and is recommended as a cost-effective means of reducing
soil erosion (Unger and McCalla, 1980).

Chisel plowing is a tillage operation that is accomplished by chisel points or
sweeps attached to shanks spaced from 20 to 40 cm apart that allow penetration to
depths of 15 to 30 cm (Olson and Sander, 1988). The soil is lifted and loosened in
the tillage zone with little soil turnover, leaving most of the prior crop’s residue on
the surface. Certainly, the chisel plow is an excellent erosion control tool compared
to the moldboard plow (Wischmeier, 1973). Joint Nebraska and Illinois studies over
a 3-yr period showed slightly higher yields with moldboard plowing than with chisel
plowing (Cihacek et a1. , 1974). Chisel plow and moldboard plow gave comparable
average corn (Zea mays L.) grain yields when compared over four years on ﬁve soils
in Indiana (Grifﬁth et al., 1973).

The evolution in tillage practices for corn has leaned strongly toward no-tillage

due to the energy and cost factors of recent years (Olson and Sander, 1988). The

16

17

reduction in erosion and energy input for no-tillage has meant a greatly modiﬁed soil-
temperature—water-air environment compared to conventional tillage. Yield results for
no-tillage systems vary. Both yield losses and reduced fertilizer-use—efﬁciency
attributed to weed competition have been recorded in a number of studies on no-
tillage (Grifﬁth et al., 1973; Van Doren et a1, 1977). On the other hand in many
studies, better yields were found for no—tillage compared to conventional tillage
(Moschler et al. 1972; Al-Darby and Lowery, 1986; Phillips et al., 1980), especially
on medium to coarse-textured soils with good internal drainage. Initially, much of
the beneﬁt was attributed to greater soil moisture storage and preservation in the root
zone. After several years of continuous no-tillage, there were greater reserves of
potentially nrineralizable N because of increased surface soil levels of organic matter,
microbial biomass, and aerobic organisms. Poorest results from no-tillage occurred
on poorly drained soils, where surface residues accentuate the cool temperature
problem early in the growing season.

A ridge surface conﬁguration is often used as a soil management tool to
improve the plant root environment. Walter at e1. (1991) summarized four ridge till
advantages: 1) increased surface drainage and warmer soil temperatures in the
vicinity of the ridge which promotes seed germination and seedling growth; 2)
elimination of fall plowing and increased soil residue cover, which decrease soil
erosion by wind and water; 3) the use of cultivation and banded application of
herbicides which reduces the need for chemical weed control; 4) banded fertilizer

applications improve yields in both uninfected and root worm-infested plants. Yield

18

increases may occur because the highly fertilized nricroenvironment promotes root
growth and lateral root proliferation.

In a 20 year study with soybeans (Glycine max (L. ) Hem), Dick and Van
Doren (1985) reported that the advantage of different tillage systems is dependent on
soil type. On a well-drained silt loam soil, soybeans grown under no-till consistently
had a yield advantage over soybeans grown under conventional tillage. While on a
poorly drained silty clay loam soil, conventional tillage had the yield advantage. Other
scientists have shown a reduction in yield with no-till on silty clay loam soils with
poor internal drainage (Webber et. al., 1987)

Tillage systems can affect soil physical properties and, thus, have a direct
bearing on crop performance. As tillage is reduced, bulk density and soil strength
increase, air-ﬁlled porosities decrease, soil moisture at shallow depths increases, and
soil temperature decreases, especially early in the growing season (Bauder et a1. ,
1981; Soane and Pidgeon, 1975). As soil strength increases, root elongation rates
decrease. Therefore, tillage would be expected to affect the ability of plants to
utilize soil nutrients.

It has been well-documented that animal manure, as an organic fertilizer,
supplies substantial amounts of plant nutrients. Manure can increase soil productivity
and improve soil physical properties and water holding capacity (Olson et a1. , 1970).
The type of crop grown, crop rotations, and tillage also affect soil physical condition
(Warren, 1985). In recent years, environmental concerns about huge manure

stockpiles have renewed interest in the use of manure for agronomic applications.

19

However, very few experiments on long-term efﬁciency of animal manure for crop
production have been conducted.

In recent years, interest in developing low chemical input systems for crop
production has grown. This interest has been fueled by a diversity of factors,
including groundwater and surface water degradation, increased soil erosion, health
hazards of agricultural chemicals and the economic farm crisis of the mid-19803.
There are three important components included in low-input systems: crop rotation,
use of animal manure and appropriate conservation tillage systems. Interactions
between tillage, manure application and chemical input have received limited
attention.

This study examined the inﬂuences of conservation tillage systems, residual
beneﬁts of long-term animal manure applications, and chemical inputs on corn and

soybean production, N uptake, and on soil physical properties over a four-year

period.

20

MATERIALS AND METHODS

A four-year experiment was conducted from 1990 to 1993 at the Kellogg
Biological Station (KBS), Hickory Comets, Michigan, as an extension of an
experiment that was initiated in 1981 to examine the effect of tillage system on corn
production and soil properties on a Kalamazoo Loam (Bronson, 1989). The soil was
a Kalamazoo loam (ﬁne loamy, mixed, mesic, Typic Hapludalf), with Ap horizon
(loam) 20 cm thick overlying a Bt horizon (clay loam) approximately 50-60 cm thick
which was underlain by a coarse glacial outwash parent material. The near surface
aquifer was approximately 10 m deep, and the soil was well-drained with a 2% slope.

The experimental design was a strip-plot with randomized complete block
split-plot, with manure application arranged as the main plots and tillage and chemical
input as the randomized complete block with four replications. Individual plots
measured 14.1 by 9.1 m. Rainfall data was obtained from the W.K. Kellogg
Biological Station about four kilometers northwest of the experimental plot.

In the initial experiment, manure applications were made to the appropriate
plots in the early spring from 1981 to 1988 using manure from the KBS dairy
operation. The manure included signiﬁcant amounts of straw. Rates of application
were approximate, but ranged from 22-27 Mg ha" of dry matter (Bronson, 1989).
Manure applications ceased after 1988 in order to evaluate the residual effects of

manure history in this study. Tillage systems included spring chisel plowing with

21

secondary tillage (CP), no—till (NT), and ridge tillage (RT). All NT plots were slot
planted with no other soil disturbance. Ridges, made during the last cultivation of the
previous crop, were scraped with sweeps and planted in the same operation. The
two chemical input treatments were high chemical input (III), which included
recommended rates of fertilizers and pesticides, and low chemical input, which
included no fertilizer applications and banded herbicides at areal rates equivalent to
those used in HI. The fertilizer for corn included 33 L ha" of 10-34-0 starter
fertilizer applied with the planter and 140 kg N ha" as NIL-NO, applied as a pre-
emergence broadcast application. No fertilizers were applied for soybeans as soil
fertility was adequate. Standard herbicides for corn and soybeans grown in rotation
were applied at labeled rates, including a contact herbicide applied in NT. Corn was
grown in rotation with soybean and each crop appeared each year in separate
experimental blocks.

Corn was planted in 76-cm row spacings at seeding rates of approximately
64,220 seeds ha"on 7 May, 1990, 8 May, 1991, 12 May, 1992, and 11 May, 1993
(Pioneer 3744, Pioneer 3704, Pioneer 3704 and Pioneer 3751, respectively). Soybean
was planted at seedling rates of approximately 60.5 kg ha" on 25 May, 1990, 20
May, 1991, 19 May, 1992, and 12 May, 1993. Corn was harvested on 16
November, 1990, 22 November, 1991, 30 November, 1992, and 22 October, 1993.
Grain yield and grain moisture were determined by combine-harvesting 6 rows of
each plot. Corn grain yields were adjusted to the standard moisture content of

15.5%. Plant populations were calculated by counting the number of plants in a

22

combine-harvesting the 6 rows of each plot. Soybeans were harvested on 23 October,
1990, 9 October, 1991, 27 October, 1992, and 8 October, 1993 by direct cutting with
a plot combine. The harvest area for each plot was 2.28 m by 14.1 m. Soybean grain
yields were adjusted to the standard moisture content of 14.0%. Plant populations
were calculated by counting the number of plants in a 1 m length of three rows in
each plot.
Plant Samplins

Five corn plants were sampled to determine above-ground biomass and
nitrogen content when 50% of the plants were silking. After formation of a black
layer, 10 plants were sampled from each plot to determine above-ground biomass. At
harvest, stover and grain were analyzed separately for nitrogen content determination.
Soybean leaves (20 per plot) were sampled when 50% of the plant were ﬂowering in
each plot to determine N content of leaves. Plant tissue was oven dried at 65 °C and
grounded to pass through a 30-mesh sieve. A 0.1 g tissue sample was digested using
standard Kjeldahl procedures (Bremner and Mulvaney, 1982). The N concentration in
the digestion was analyzed colorimetrically for NIL-N using a Lachet injection ﬂow
analyzer.
Soil Smplins

Three intact soil cores (7.6 cm diameter by 7.6 cm height) were taken from
the 0 to 7.6 cm and 7.6 to 15.2 cm depths from all tillage and manure treatments
under high chemical input on 22 April, 1992 and from the 0 to 7 .6 cm depth on 12

November, 1993. Soil cores were saturated by wetting from the bottom for 48 hours

23

before the saturated hydraulic conductivities (K-sat) were determined by the constant
head method (Klute and Disksen, 1986). The cores were resaturated and moisture
retention determined at matric potentials of -l and -2 kPa using the blotting paper
method (Learner and Shaw, 1941), and at matric potentials of -6, -33.3 and -100 kPa
with a pressure chamber. In 1993, moisture retention was determined only at -6, -33
and -100 kPa of pressure. Cores were oven-dried at 105° C for 48 hours and weighed
for bulk density determination (Blake and Hartge, 1986). Water loss between
saturation and oven drying was taken to represent total soil porosity. Macroporosity
(Carter, 1988; Hamblin, 1985) was determined by subtracting the measured
volummetlic water at -6 kPa (equivalent pore radius of 24 pm) from the total porosity
(Carter, 1988).

The analysis of variance was performed using general linear models’
procedures (SAS Inst. , 1990) as detailed in Table 1. Mean differences were

determined using a least signiﬁcant difference (LSD) at the 0.05 level of probability.

RESULTS AND DISCUSSION

 

A broad range of weather was encountered during the 4 year period of this
study and this had a large impact, both positive and negative, on crop production.
Both the amount and distribution of growing season rainfall varied, with seasonal

rainfall high in 1990 and 1991 and average in 1992 and 1993 (Figure l).

2 4
Cumulative growing degree days were exceptionally high in 1991 and exceptionally
low in 1992, with 1990 and 1993 about average (Figure 2). Thus, 1990 had a cool,
very wet spring followed by below normal rainfall for July, August and September.
In 1991, it was a warm, moist year in which corn matured very early with high
yields. In 1992, it was very dry in May and June, followed by a wet, very cool
summer, and was a year in which corn matured very late, with grain moisture at
harvest very high. Additionally, white mold was a major problem in soybean in 1992
and depressed yields statewide. 1993 was dry and cool in May followed by a very wet
June, and had rather normal rainfall throughout the growing season. Thus, corn and

soybean yields varied greatly with year, with the range in yields probably

representative of the potential for this soil and climate.

 

In 1990, corn yields were low, less than 4.05 Mg ha", and were not affected
by any treatment (Table 2). The low yields were associated with reduced plant
populations (Table 3) and reduced plant biomass (Table 4), resulting from stand loss
and reduced growth caused by cool, wet conditions during the early spring in 1990
(Figure 1 and 2). Corn grain moisture at harvest was not affected by treatments in
any year. In 1991, under growing conditions of adequate moisture and high growing
degree units, corn yields were highest under HI. However, the reduction in corn
yield in L1 was less where manure had been applied (-1.63 Mg ha") than where no

manure had been applied (-3.63 Mg ha") and under CP (-1.56 Mg ha") compared to

25

NT (-4.10 Mg ha") and RT (-2.22 Mg ha") (Table 2). It appears that both manure
and soil disturbance by chisel plowing increased N supply to the corn, although there
were no differences in N content of corn tissue at silking or harvest due to manure or
tillage in 1991 (Table 4). Ridge till had lower plant populations than CP in 1991 and
this may be partially responsible for lower yields in RT. Corn stover was not
affected by input level where manure had been applied but was reduced under LI
where no manure had been applied (Table 4). Stover was higher in CP than either
NT or RT, indicating reduced growth in these tillage systems. In 1992, only input
affected corn yield, with L1 42 % lower than III (Table 2). Corn stover was lower in
L1 than HI, with the difference larger in CP than in NT or RT and was lower in RT
than CP (Table 4). Plant populations were lower in CP than NT (Table 3) but this
had no effect on grain or stover yields. In 1993, a year of normal rainfall with
slightly lower temperatures, there were no interaction effects on grain yield. Grain.
yields were increased by manure application and chemical application but not affected
by tillage (Table 2). Corn stover was considerably lower under LI than HI, although
the difference between HI and LI varied with tillage (Table 4). No-till had lower
corn stover under HI than CP and RT and RT had the lowest stover under LI. Plant
populations were slightly lower in RT and CP under LI than HI (Table 3).

Over the 4 year period, corn yields were greatly reduced under LI, slightly
higher where manure had been applied, and not greatly affected by tillage. Lower
input had less effect where manure had been applied and under CP in 1991, indicating

a lower potential for yield reductions under LI where mineralization of N is enhanced.

26

Corn stover was lower under LI, no manure, and NT or RT, but the differences were
not as large as in grain yield. Plant population and grain moisture were not greatly

affected by treatments but varied considerably with year.

W

With N limiting corn yields, N uptake differences would be expected. N
concentration at silking was greatly reduced in L1 corn plants each year and N
concentration in L1 corn at silking appeared to decline each year (Table 5). LI
reduced N content in the corn grain and stover each year. Manure increased N
content in the grain in all but 1991 but not in the stover. Tillage had little effect on
tissue N concentration, with the exception of an increase in stover N in RT and a
decrease in tissue N at silking in NT, both in 1990.

Corn whole-plant N uptake at silking was higher for high chemical treatments
in all four years (Table 6, 7, 8, 9), with NT higher than CP and RT under HI but not
different under L1 in 1990 only (Table 6). N uptake at silking was higher in CP than
either NT or RT in 1991 and 1992, and lower in NT than CP and RT in 1993.
Manure narrowed the difference between HI and L1 in 1992, but otherwise had no
effect on N uptake at silking.

N uptake in corn grain was much higher in HI than LI but the difference was
affected by tillage in all four years (Tables 6, 7, 8, 9). In 1991, N uptake was
similar for tillage systems under HI but much higher in CP than either NT or RT,

reﬂecting the higher yield (Table 2). In 1992 and 1993, N uptake in CP was

27

generally higher than RT and NT under HI but similar under LI. In 1990, N uptake
was low due to low yields and NT had higher N uptake than CP. In 1992, manure
increased N uptake in NT and RT but not in GP (Table 8). N uptake in the corn
stover was much higher in HI than LI but the difference was slightly affected by
tillage in 1991 and 1993 and reduced by manure application in 1991 and 1992. In
1992, manure reduced the difference between III and LI and decreased N uptake in
the stover in CP but increased it in NT (Table 8). Total N uptake was much higher
in III than LI but the difference varied with tillage. N uptake tended to be higher in
CP than NT and RT under HI but similar under LI except in 1991 where CP in L1
was not reduced as much as in NT and RT. In 1992, manure reduced the difference
in total N uptake between HI and LI and increased N uptake in NT and RT but not
CP.

Over the four year period, chemical input had the greatest impact on N
concentration in corn tissue and N uptake. The difference in N uptake between HI

and LI was tempered by manure application and affected by tillage. Manure, and to

some extent chisel plowing, tended to increase N uptake in corn.

 

Soybean yields were less affected by treatments than corn (Table 10). The
major effect of tillage was a reduction in yields under CP in 1990 and 1993. In 1990,
soybeans were replanted due to poor emergence in a soil crusted under the impacts of

high rainfall in 1990. In 1993, the stand was poor also but soybeans were not

28

replanted (Table 11). Stands were also reduced in CP in 1992, but plant populations
were sufﬁcient given low yields in a year characterized by white mold infestations
statewide. The effect of manure was primarily to increase weed pressure due to weed
seeds added in the bedding straw during the years of manure application. This is
evident in yields in the tillage by manure interaction in 1990, 1992, and 1993. The
effect of manure was also evident in the reduced plant populations in 1992 and 1993
in the manured soybeans. Chemical input had little effect on soybean yield, except in
1992, when HI had higher yields than LI. Again, this was the year of white mold
and weed control may have been important in the development of the disease. Under
high yields of 1991, treatments had no effect on soybean.

Over the four year period, soybeans were affected mainly by soil crusting in
CP and weed pressure in manured treatments but were relatively unaffected by

chemical input treatments. Treatments had little important effects on grain moisture

or N content of seed or leaves at ﬂowering.

 

Bulk density at the 0 to 7.6 cm depth under RT was signiﬁcantly lower than
those under CP and NT treatments in 1992 (Table 12). Ridge till also had higher
saturated conductivity (K-sat) and higher total porosity compare to CP and NT.
There were no differences in macroporosity (> 241m in diameter) between the three
tillage treatments and no difference in bulk density at the 7.6 to 15 .2 cm depth

between tillage treatments. Saturated conductivity was higher for RT than for NT and

29

CP. Total porosity at the 7.6 to 15.2 cm depth was slightly higher for the CP. Air-
ﬁlled porosity was only slightly higher for RT at the 0 to 7 .6 cm depth at matric
potentials of -l kPa. At the depth of 7.6 to 15.2 cm, CP had higher air-ﬁlled
porosity at matric potentials between -1 and -100 kPa (Figure 3).

In 1993, total porosity under RT was slight higher compared to NT and CP.
Chisel plow had higher air-ﬁlled porosity at matric potentials of -10, -33.3 and -100
kPa (Table 13). Manure application reduced bulk density, increased total porosity
and macroporosity. Manure application also increased air-ﬁlled porosity at matric

potential of -10 and -100 kPa (Figure 4).

SUMMARY AND CONCLUSIONS

Corn response to tillage varied greatly depending on temperature, rainfall
distribution and other factors. In years with low rainfall and/or poor rainfall
distribution, tillage did not affect yields. In years with sufﬁcient rainfall, interaction
effects between tillage systems and chemical inputs occurred. Corn grain yield and
stover weight were higher for NT under HI, and lower for NT under LI. At low
rates of N fertilizer, NT and RT corn were generally more deﬁcient in nitrogen and
yields were less than under CP. For maximum corn yields, more N fertilizer would
be required for NT and RT soils. Both low and high chemical input treatments did
not affect weed control, since there was no difference in corn plant populations under

both systems. The reason for low corn yields under ridge till was also attributed

30

lower plant populations caused by cultivation.

High chemical input increased N uptake and N concentrations in corn tissue
and N uptake. The differences in N uptake between HI and LI were tempered by
manure applications and affected by tillage. Manure application history with chisel
plowing tended to increase N uptake in corn.

Manure application history resulted in higher weed populations causing lower
soybean plant populations and ultimately decreased soybean production. Chemical
inputs to corn did not affect soybean grain yield. Both NT and RT are preferable
tillage methods for soybean production in the Kalamazoo loam soil of Michigan.
Under those two tillage systems, weed control was improved, plant population was
well-distributed, plant growth was good, and yields were increased, compared to CT
treatment.

The effects of tillage treatments on soil physical properties varied depending
on sampling time. Ridge till increased air-ﬁlled porosity at 7.5 to 15 cm depths
before planting and at 0-7.5 cm depths after harvest. Bulk density was lower and
total porosity was higher in ridge till after harvest, but there was no difference in
tillage treatments before planting. Manure applications decreased bulk density and

increased total porosity, macroporosity, air-ﬁlled porosity.

Al-D:

Baud

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Bro:

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Dick

Gn'fﬂ

LIST OF REFERENCES

Al-Darby, A. M. , and B. Lowery. 1986. Evaluation of corn growth and
productivity with three conservation tillage systems. Agron. J. 8:901-
907.

Bauder, J.W., G. W. Randall, and LB. Swan. 1981. Effect of four
continuous tillage systems on mechanical impedance of a clay loam
soil. Soil Sci. Soc. Am. J. 45:802-806.

Blake, G. R. and K. H. Hartge. 1986. Bulk density. In: A. Klute (editor),
Methods of soil Analysis, Part 1. Physical and Mineralogical Methods,
2nd ed. American Society of Agronomy, Madison, WI, pp 363-376.

Bremner, J. M., and C. S. Mulvaney. 1982. Nitrogen - Total. pp. 595-624
In A. L. Page, R. H. Miller, and D. R. Keeney (ed.) Methods of Soil
Analysis. Part 2. Chemical and Microbiological properties. Second
Edition. Agronomy 9. ASA-CSSA-SSSA, Madison, WI.

Bronson, J. A. 1989. The effect of tillage system on corn production and soil
properties on a Kalamazoo Loam. M.S. Thesis. Michigan State
university. East Lansing, MI.

Carter, M.R. 1988. Temporal variability of soil macroporosity in a ﬁne
sandy loam under moldboard ploghing and direct drilling. Soil tillage
Res. 12:37-51.

Cihacek, L.J., D.L. Mulvaney, R.A. Olson, L.F. Welch, and R.A. Wiese.
1974. Phosphate placement for corn in chisel and moldboard plowing
systems. Agron. J. 66:665-668.

Dick, W.A., and D.M. Van Soren, Jr. 1985. continuous tillage and rotation
combinations defects on corn, soybean, and oat yields. Agron. J.
77:459-465.

Grifﬁth, D.R., Mannering, J.V. Galloway, H.M., Parsons, SD. and C.B.
Richey. 1973. Effect of eight tillage-planting systems on soil
temperature, percent stand, plant growth, and yield of corn on ﬁve
Indiana soils. Agron. J. 65:321-326.

31

32

Hamblin, A.P. 1985. The inﬂuence of soil structure on water movement,
crop root growth, and water uptake. Adv. Agron. 38:95-158.

Klute, A. and Dirksen, C. 1986. Hydraulic conductivity and diffusivity:
laboratory methods. In: A. Klute (editor), Methods of soil Analysis,
Part 1. Physical and Mineralogical Methods, 2nd ed. American Society
of Agronomy, Madison, WI, pp 687-770.

Learner, R.W. and B. Shaw. 1941. A simple apparatus for measuring non-
capillary porosity on an extensive scale. J. Am. Soc. Agron. 33:1003-
1008.

Moschler, W.W., G.M. Shear, D.C. Martens, G.D. Jones, and RR.
Wilmouth. 1972. Comparative yield and fertilizer efﬁciency of no-
tillage and conventionally till corn. Agron. J. 64:229-231.

Olson R.A. and DH. Sander. 1988. Corn production. In G.F. Sprague and
J.W. Dudley (ed) Corn and corn improvement 3rd edition. Agronomy
18:639-685.

Olson, R.J., R.F. Hensler, and OJ. Attoe. 1970. Effect of manure
application aeration, and soil pH on soil nitrogen transformation and on
certain soil test values. Soil Sci. Sco. Am Proc. 38:830-836.

Phillips , R.E., R.L. Blevins, G.W. Thomas W.W. Frye, and SH. Phillips.
1980. No-tillage agriculture. Science (Washington, DC) 208: 1 108-
1113.

SAS Institute. 1990. SAS/STAT user’s guide. Version 6. SAS Inst., Cary, NC.

Soane, ED. and JD. Pidgeon. 1975. Tillage requirements in relation to soil
physical properties. Soil Sci. 119:376-384.

Unger, P., and T.M. McCalla. 1980. Conservation tillage systems. Adv.
Agron. 33:1-58.

Van Doren, D.M., Jr., G.B. Triplett, Jr.,and J.E. Henry. 1977. Inﬂuence of
long-term tillage and crop rotation combinations on crop yields and
selected soil parameters for Aerie Ochraqualf soil. Ohio Agric. Res.
and Dev. Ctr. Res. Bull. 1091.

Walter E. Riedell, Ralph D. Gustin, Dwayne L. Beck, and Denise G. Hanson,
1991. Western corn rootworm damage: effect of tillage on plant
response and grain yield. Crop Sci. 31:1293-1297.

33

Warren W. Saba and Gary Lesoing. 1985. Crop rotation and manure versus
agricultural chemicals in dryland grain production. J. Soil and Water
Conserv. 40:511-516.

Webber III, C. L. , M.R. Gebhaedt, and H.D. Kerr. 1987. Effect of tillage
on soybean growth and seed production. Agron. J. 78:952-956.

Wischmeier, W.H. 1973. Conservation tillage to control water erosion
p.133-141. In Conservation tillage. Proc. Natl. Conf., Des Moines, IA.
28-30 March. Soil Conserve. Soc. Am., Ankeny, IA.

34

Table 1. Analysis of variance table.

 

_S_QURQE_ W

 

Total R*M*T*C-1 4*2‘2*3*3-1 =47
RT R-l 4-1 =3
M1: M-l 2-1 =1
ERROR I (R-1)*(M-1) (4-1)*(2-l) =(4-1)*(2-1) =3
T§ T-l 3-1 =2
C1 C-l 2-1 =1
T'C (T-1)*(C-1) (3-1)*(2-1) =2
ERROR II (R-1)*(T*C-l) (4-1)*(3"2-1) = 15
M*T (M-l)*(T-l) (2-1)*(3-1)=2
M*C (M-l)*(C-1) (2-1)*(2-1) =1
M*C“"T (M-1)*(C-1)*(T-l) (2-1)*(2-1)*(3-1) =2
ERROR III (R-1)*(M-1)*(T*C-l) (4-1)*(2-1)*(3*2-1)=15
1‘ replication
1 manure
§ Tillage

1 chemical input

35

Table 2. Corn grain yield (@15 .5 % moisture) as affected by manure application
history, chemical input, and tillage treatments for the period 1990 to 1993.

 

 

 

 

 

Treatment 1990 1991 1992 1993 4-yr mean
Mg ha"
Manure/High input 3.4 9.7 8.2 10.1 7.9
Manure/Low input 3.3 8.1 5.1 6.6 5.8
No-rnanure/High input 3.7 10.0 7.9 9.7 7.8
No—manure/Low input 2.9 6.39 4.3 5.3 4.7
LSD(0.05) NS *** NS NS
High input/Chisel plow 3.1 10.2 9.0 10.3 8.1
High input/No-tillage 4.1 10.3 7.4 9.6 7.8
High input/ridge till 3.4 9.1 7.7 9.8 7.5
Low input/Chisel plow 2.8 8.6 4.4 5.8 5.4
Low input/No-tillage 3.2 6.2 4.8 5.7 5.0
Low input/Ridge till 3.2 6.9 4.8 6.3 5.3
LSD(0.05) NS *** NS NS
Chisel plow/Manure 3.2 9.7 6.6 8.6 7.0
Chisel plow/No—manure 2.7 9.1 6.8 7.5 6.5
No-tillage/Manure 3.5 8.8 6.4 8.0 6.7
No-tillage/No-manure 3.7 7.8 5.9 7.3 6.2
Ridge till/Manure 3.3 8.2 6.9 8.6 6.8
Ridge till/No-manure 3.3 7.8 5.6 7.5 6.1
LSD(0.05) NS NS NS NS
Manure 3.3 8.9 6.6 8.4 6.8
No-manure 3.3 8.2 6.1 7.5 6.3
LSD(0.05) NS NS NS 0.44
High Input 3.5 9.9 8.0 9.9 7.8
Low Input 3.1 7.2 4.7 6.0 5.2
LSD(0.05) NS 0.8 1.32 1.1
Chisel plow 2.9 9.4 6.7 8.0 6.8 .
No-tillage 3.6 8.3 6.1 7.7 6.4
Ridge till 3.3 8.0 6.3 8.1 6.4
LSD(0.05) NS 0.7 NS NS

 

NS: not signiﬁcant.
*** Signiﬁcant at 0.01 probability levels.

36

Table 3. Corn plant population as affected by manure application history, chemical
input and tillage treatments for the period 1990 to 1993.

 

 

 

 

Treatment 1990 1991 1992 1993 4-yr mean
1000 plants ha"
Manure/High input 26.9 59.4 55.1 60.3 50.4
Manure/Low input 29.4 61.8 53.4 50.2 50.2

No-manure/High input 33.2 63.2 53.5 51.8 51.8
No-manure/Low input 32.9 59.9 52.8 49.7 49.7

 

LSD(0.05) NS NS NS NS
High input/Chisel plow 27.7 63.2 53.3 51.5 51.4
High input/No-tillage 34.3 62.5 55.1 51.7 51.7
High input/ridge till 28.1 58.2 54.5 50.3 50.3
Low input/Chisel plow 24.7 63.7 51.4 49.8 49.8
Low input/No—tillage 36.0 60.2 56.3 51.6 51.6
Low input/Ridge till 32.8 58.6 51.5 48.3 48.3
LSD(0.05) * NS NS **
Chisel plow/Manure 26.4 63.6 53.6 61.3 51.2
Chisel plow/No—manure 26.0 63.3 51.1 59.5 50.0
No-tillage/Manure 29.8 61.0 55.6 57.0 50.8
No-tillage/No-manure 40.6 61.7 55.9 51.8 52.5
Ridge till/Manure 28.3 57.2 53.5 56.2 48.8
Ridge tilllNo-manure 32.6 59.6 52.5 54.5 49.8
LSD(0.05) NS NS NS NS
Manure 28.1 60.6 54.2 58.2 50.3
Non-Manure 33.0 61.5 53.2 55.3 50.7
LSD(0.05) NS NS NS NS
High Input 30.0 61.3 54.3 58.9 51.1
Low Input 31.2 60.8 53.1 54.6 49.9
LSD(0.05) NS NS NS NS
Chisel plow 26.2 63.5 52.4 60.4 50.6
No-tillage 35.2 61.3 55.7 54.4 51.7
Ridge till 30.4 58.4 53.0 55.4 49.3
LSD(0.05) 4.30 3.50 3.13 NS

 

NS not signiﬁcant.
*, " Signiﬁcant at 0.1 and 0.05 probability levels.

37

Table 4. Corn stover weight (Mg ha") at black layer as affected by manure
application history, chemical input and tillage treatments for the period

 

 

 

 

 

1990 to 1993.
Treatment 1990 1991 1992 1993 4-yr mean
Mg ha"
Manure/High input 1.8 5.1 4.8 7.7 4.8
Manure/Low input 1.9 4.8 3.6 5.5 3.9
No-manure/High input 2.2 5.3 4.2 7.3 4.7
No-manurelLow input 1.8 3.9 3.1 4.7 3.4
LSD(0.05) NS ** NS NS
High input/Chisel plow 1.9 5.5 5.0 8.1 5.1
High input/No-tillage 2.3 5.3 4.3 6.6 4.6
High input/ridge till 1.7 4.7 4.2 7.9 4.6
Low input/Chisel plow 1.8 5.2 3.5 5.5 4.0
Low input/No-tillage 1.9 3.9 3.7 5.0 3.6
Low input/Ridge till 1.9 3.9 3.0 4.7 3.4
LSD(0.05) ** NS * ***
Chisel plow/Manure 2.0 5.6 4.3 7.1 4.7
Chisel plow/No-manure 1.7 5.1 4.2 6.5 4.4
No-tillage/Manure 1.9 4.8 4.5 6.3 4.4
No-tillage/No—manure 2.3 4.5 3.4 5.3 3.9
Ridge till/Manure 1.7 4.4 3.8 6.3 4.1
Ridge till/No-manure 1.9 4.2 3.3 6.2 3.9
LSD(0.05) NS NS NS NS
Manure 1.7 4.9 4.2 6.6 4.4
Non-manure 2.0 4.6 3.6 6.0 4.1
LSD (0.05) NS NS NS NS
High Input 2.0 5.2 4.5 7.5 4.8
Low Input 1.9 4.3 3.4 5.1 3.7
LSD(0.05) NS 0.66 0.54 0.4
Chisel plow 1.9 5.3 4.3 6.8 4.6
No-tillage 2.1 4.6 4.0 5.8 4.1
Ridge till 1.9 4.3 3.5 6.3 4.0
LSD(0.05) NS 0.61 0.50 0.40

 

NS not signiﬁcant.
*, "* Signiﬁcant at 0.1 and 0.01 probability levels.

38

Table 5. Nitrogen concentration of corn grain, stover at black layer, and tissue on
silking for the period 1990 to 1993.

 

 

Treatment 1990 1991 1992 1993 4-yr mean
Grain Nitrogen (mg kg")

Manure 14,344 15,921 12,795 10,822 13,470

Non-Manure 12,958 14,722 11,817 10,315 12,453
LSD(0.05) 548 NS 107 321

High input 14,758 16,945 13,440 12,360 14,375

Low input 12,543 13,748 11,173 8,778 11,560
LSD(0.05) 900 1,879 656 769

Chisel plow 13,468 15,823 12,207 10,866 13,091

No-tillage 13,637 15,440 12,606 10,199 12,970

Ridge till 13,845 14,776 12,106 10,641 12,842
LSD(0.05) NS NS NS NS

Stover Nitrogen (mg kg")

Manure 10,735 9,947 9,788 7,042 9,378

Non-Manure 9,414 8,890 10,539 6,447 8,822
LSD(0.05) NS NS NS NS

High input 12,193 10,666 11,233 8,276 10,592

Low input 7,956 8,170 9,094 5,213 7,608
LSD(0.05) 1,541 1,499 1,700 1,583

Chisel plow 9,835 9,271 9,686 6,901 8,923

No-tillage 9,322 9,537 10,514 6,561 8,983

Ridge till 11,066 9,447 10,289 6,772 9,393
LSD(0.05) 1,442 NS NS NS

 

 

 

 

Table 5 (cont’d)

39

--------- Whole plant Nitrogen on Silking(mg kg")------—---

Manure 24,116 18,461 14,964 15,022 18,140
Non-Manure 22,423 17,946 14,520 14,357 17,311
LSD(0.05) NS NS NS NS
High input 26,038 20,667 16,876 18,785 20,591
Low input 20,501 15,740 12,616 10,595 14,863
1313(005) 1,960 3,332 1,264 2,190
Chisel plow 23,388 18,491 14,902 14,712 17,873
No-tillage 21,845 17,164 14,173 14,617 16,949
Ridge till 24,575 18,955 15,150 14,740 18,355
Lemons) 1.833 NS us NS

 

40

Table 6. Corn plant tissue N content at silking, N content of grain and stover, and
total N uptake at black layer as affected by manure application history,
chemical input and tillage treatments in 1990.

 

 

 

 

Whole Total
Treatment Plant Grain Stover Uptake
kg ha“
Manure/High input 73.9 50.5 26.0 76.5
Manure/Low input 58.7 42.4 16.6 58.9

No-manure/High input 76.5 51.3 24.7 75.9
No-manure/Low input 54.5 33.6 13.7 47.3

 

LSD(0.05) NS NS NS NS
High input/Chisel plow 72.9 44.3 23.7 68.0
High input/No-tillage 85.8 58.5 27.1 85.6
High input/ridge till 67.0 49.8 25.3 75.1
Low input/Chisel plow 53.4 33.6 14.0 47.6
Low input/No—tillage 59.1 40.0 13.0 53.1
Low input/Ridge till 57.3 40.5 18.4 58.7

18D(0.05) *8 *1“! *4! II
Chisel plow/Manure 68.9 43.6 21.8 65.4
Chisel plow/No-manure 57.4 34.3 15.9 50.2
No—tillage/Manure 71.5 48.8 20.3 69.2
No-tillage/No—manure 73.4 49.7 19.8 69.5
Ridge till/Manure 58.5 46.9 21.8 68.6
Ridge till/No-manure 65.8 43.3 22.0 65.2

LSD(0.05) NS NS NS NS

Manure 66.3 46.4 21.3 67.7
Non-manure 65.5 42.4 18.2 61.6
LSD(0.05) NS NS NS NS
High Input 75.2 50.9 25.4 76.2
Low Input 56.6 38.0 15.1 53.1
LSD(0.05) 18.2 12.2 8.8 11.8
Chisel plow 63.1 38.9 18.9 57.8
No-till 72.4 49.3 20.0 69.3
Ridge till 62.1 45.1 21.3 66.9
LSD(0.05) NS NS NS NS

 

NS not signiﬁcant. *, ", *** Signiﬁcant at 0.1, 0.05, and 0.01 probability levels.

41

Table 7. Corn plant tissue N content at silking, N content of grain and stover, and
total N uptake at black layer as affected by manure application history,
chemical input and tillage treatments in 1991.

 

 

 

 

 

Whole Total
Treatment Plant Grain Stover Uptake
kg ha"
Manure/High input 102.7 171.5 55.1 226.5
Manure/Low input 67.5 126.4 43.0 169.8
No-manure/High input 92.7 162.8 54.9 217.4
No-manure/Low input 47.8 85.2 36.1 114.6
LSD(0.05) NS NS ** NS
High input/Chisel plow 104.6 167.9 54.8 224.1
High input/No-tillage 91.5 174.1 57.8 232.9
High input/ridge till 97.2 159.4 52.5 208.9
Low input/Chisel plow 79.7 132.0 36.9 175.8
Low input/No-tillage 46.5 87.7 42.7 119.0
Low input/Ridge till 46.8 97.7 39.2 131.8
LSD(0.05) NS *** NS *
Chisel plow/Manure 109.6 163.9 55.5 219.4
Chisel plow/No-manure 74.7 136.0 36.2 180.5
No-tillage/Manure 76.3 142.1 44.9 187.0
No-tillage/No-manure 61.7 119.1 55.5 164.9
Ridge till/Manure 69.5 140.8 46.8 188.2
Ridge tilllNo-manure 74.5 116.3 44.9 152.5
LSD(0.05) NS NS NS **
Manure 85.1 150.0 49.1 127.8
Non-manure 70.3 123.0 42.0 114.1
LSD(0.05) NS 18.6 NS NS
High Input 97.7 167.1 54.8 157.6
Low Input 57.6 105.4 36.2 84.3
LSD(0.05) 18.4 17.8 9.4 17.5
Chisel plow 92.1 149.9 50.0 126.7
No-tillage 68.9 130.9 45.1 121.3
Ridge till 72.0 129.5 41.5 114.8
LSD(0.05) 17.2 16.7 8.7 NS

 

NS not signiﬁcant. *, *"‘, **"' Signiﬁcant at 0.1, 0.05, and 0.01 probability levels.

42

Table 8. Corn plant tissue N content at silking, N content of grain and stover, and
total N uptake at black layer as affected by manure application history,
chemical input and tillage treatments in 1992.

 

 

 

 

 

Whole Total
Treatment Plant Grain Stover Uptake
kg ha"

Manure/High input 129.9 110.2 48.1 158.3
Manure/Low input 84.3 62.4 34.8 97.3
No—manure/High input 122.2 105.7 51.1 156.8
No-manure/Low input 63.3 43.8 27.6 71.4
LSD(0.05) ** NS *" **
High input/Chisel plow 144.7 122.9 52.5 175.4
High input/No-tillage 117.9 98.2 49.1 147.3
High input/ridge till 115.5 102.7 47.3 150.0
Low input/Chisel plow 80.6 47.1 31.0 78.1
Low input/No-tillage 71.4 59.2 36.2 95.3
Low input/Ridge till 69.5 53.1 26.7 79.6
LSD(0.05) NS ** NS **
Chisel plow/Manure 121.1 83.3 36.9 123.2
Chisel plow/No-manure 104.1 83.7 46.6 130.3
No-tillagelManure 101.4 85.7 49.1 134.8
No-tillage/No—manure 87.9 71.7 36.2 107.9
Ridge till/Manure 98.8 87.0 38.5 125.4
Ridge till/No-manure 86.2 68.9 35.4 104.2
LSD(0.05) NS ** ** **
Manure 107.1 86.3 41.5 127.8
Non-manure 92.7 74.7 39.4 114.1
LSD(0.05) NS NS NS NS
High Input 126.0 107.9 49.6 157.6
Low Input 73.8 53.1 31.2 84.3
LSD(0.05) 14.5 17.4 11.8 17.5
Chisel plow 112.6 85.0 41.7 126.7
No-tillage 94.6 78.7 42.6 121.3
Ridge till 92.5 77.9 36.9 114.8
LSD(0.05) 13.5 16.3 NS NS

 

NS not signiﬁcant. " Signiﬁcant at 0.05 probability levels.

43

Table 9. Corn plant tissue N content at silking, N content of grain and stover, and
total N uptake at black layer as affected by manure application history,
chemical input and tillage treatments in 1993.

 

 

 

 

 

Whole Total
Treatment Plant Grain Stover Uptake
kg ha"
Manure/High input 88.9 128.8 65.1 193.8
Manure/Low input 35.5 60.2 30.8 91.0
No-manure/High input 91.9 116.1 59.2 175.2
No-manurelLow input 27.0 44.9 22.1 67.1
LSD(0.05) NS NS NS NS
High input/Chisel plow 96.8 133.2 73.6 206.8
High input/No—tillage 75.0 110.3 51.3 161.6
High input/ridge till 99.4 123.8 61.4 185.2
Low input/Chisel plow 30.9 51.5 25.8 77.2
Low input/No-tillage 32.5 51.1 27.2 78.2
Low input/Ridge till 30.4 55.1 26.6 81.6
LSD(0.05) NS an: are: an
Chisel plow/Manure 67.0 99.7 52.5 152.1
Chisel plow/No—manure 60.6 85.0 46.9 131.8
No-tillage/Manure 50.4 87.8 47.0 134.8
No-tillage/No-manure 57.1 73.6 31.4 105.0
Ridge till/Manure 69.1 96.0 44.3 140.3
Ridge till/No-manure 60.7 82.9 43.7 126.6
LSD(0.05) NS NS NS NS
Manure 62.2 94.5 47.9 142.4
Non-manure 59.5 80.5 40.7 121.1
LSD(0.05) NS 6.2 NS 9.4
High Input 90.4 122.4 62.1 184.5
Low Input 31.3 52.5 26.5 79.0
LSD(0.05) 23.2 12.8 12.8 21.8
Chisel plow 63.8 92.3 49.7 142.0
No-tillage 53.8 80.7 39.2 119.9
Ridge till 64.9 89.4 44.0 133.4
LSD(0.05) NS NS NS 20.4

 

NS not signiﬁcant. ", "* Signiﬁcant at 0.05, and 0.01 probability levels.

44

Table 10. Soybean yield as affected by manure application history, chemical input
and tillage treatments for the period 1990 to 1993.

 

 

 

 

 

4-yr
Treatment 1990 1991 1992 1993 mean
Mg ha-l
Manure/High input 2.1 3.4 1.6 1.9 2.3
Manure/Low input 2.0 3.3 1.2 2.3 2.1
No-manure/High input 2.1 3.6 1.2 2.0 2.4
No-manurelLow input 2.0 3.4 1.4 2.3 2.3
LSD(0.05) NS NS *" ***
High input/Chisel plow 1.9 3.5 1.6 1.3 2.1
High input/No—tillage 2.6 3.4 1.6 2.3 2.5
High input/ridge till 2.1 3.5 1.6 2.7 2.5
Low input/Chisel plow 1.9 3.5 1.3 1.3 2.0
Low input/No—tillage 2.0 3.4 1.4 2.5 2.3
Low input/Ridge till 2.1 3.3 1.2 2.7 2.3
LSD(0.05) *** NS NS ***
Chisel plow/Manure 1.7 3.6 1.5 1.0 1.9
Chisel plow/No-manure 2.1 3.5 1.4 1.5 2.1
No-tillage/Manure 2.3 3.2 1.4 2.3 2.3
No-tillage/No-manure 2.3 3.5 1.6 2.5 2.5
Ridge till/Manure 2.2 3.3 1.4 2.6 2.4
Ridge till/No-manure 2.1 3.5 1.5 2.8 2.5
LSD(OOS) can NS um: um:
Manure 2.1 3.4 1.4 2.0 2.4
Non-Manure 2.1 3.5 1.5 2.3 2.6
LSD(0.05) NS NS NS 0.08
High Input 2.2 3.5 1.6 2.1 2.6
Low Input 2.0 3.4 1.3 2.1 2.4
LSD(0.05) NS NS 0.34 NS
Chisel plow 1.9 3.5 1.44 1.3 2.2
No-tillage 2.3 3.4 1.51 2.4 2.6
Ridge till 2.1 3.4 1.41 2.7 2.6
LSD(0.05) 0.2 NS NS 0.30

 

NS not signiﬁeant.
"* Signifieant at 0.01 probability levels.

Table 11. Soybean population as affected by manure application history, chemical

45

input and tillage treatments for the period 1990 to 1993.

 

 

 

 

 

3—yr
Treatment 1991 1992 1993 Mean
1000 plants ha'l
Manure/High input 280.2 186.7 91.6 186.2
Manure/Low input 261.1 197.6 103.8 187.5
No-manure/High input 277.2 202.9 126.8 202.3
No-manure/Low input 258.4 222.0 119.5 200.0
LSD(0.05) NS NS NS
High input/Chisel plow 288.7 108.6 48.1 148.4
High input/No-tillage 278.1 233.6 142.0 217.9
High input/ridge till 269.4 242.2 137.6 216.4
Low input/Chisel plow 252.2 157.9 43.3 151.1
Low input/No-tillage 277.6 255.8 163.4 232.3
Low input/Ridge till 249.4 215.9 128.3 197.8
LSD(0.05) ** ** NS
Chisel plow/Manure 272.7 188.0 36.0 142.2
Chisel plow/No-manure 268.2 148.4 55.4 157.3
No-tillage/Manure 272.3 233.6 129.4 211.8
No-tillage/No—manure 283.4 255.8 176.0 238.4
Ridge till/Manure 267.0 224.9 127.8 206.6
Ridge till/No—manure 251.8 233.2 138.2 207.7
LSD(0.05) NS NS NS
Manure 270.7 192.2 152.8 153.9
Non—manure 267.8 212.4 187.2 166.9
LSD(0.05) NS 17 .5 19.1
High input 278.7 194.8 171.0 161.1
Low input 259.7 209.8 169.7 159.8
LSD(0.05) 14.3 NS NS
Chisel plow 270.5 133.2 70.7 118.6
No-tillage 277. 8 244.7 232. 1 188.6
Ridge till 259.4 229.0 202.1 172.6
LSD(0.05) 13.3 226.0 28.8

 

NS not signiﬁeant.

** Signiﬁcant at 0.05 probability levels.

 

46

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47

 

 

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48

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j
/..-,:;'?5"“"'
1500 ~ /// #-

Growmg Degree Days
\
\.
\Q
\‘\
\

 

 

 

500 —
/ ------ 1990
—-- 1991
/ —-- 1992
0 / — 1993
I l I
o 50 100 150 200

Days After Planting

Figure 1. Cumulative growing degree days after planting for the period 1990 to
1993 at the Kellogg Biological Station.

 

 

yW/C/ /

May

 

 

Ju' A09 Sep Oct Nov

Jun

Monthly rainfall for the 1990 to 1993 growing season.

Figure 2.

50

 

    
   

 

 

 

 

H Chisel plow
0'25 _ H No-tillage
H Ridge till
0.20 -
0.15 -
0.10 -
9. 0.05 _ LSD (0.05)
a 0-7.6 cm
9
.5. 0.00
I
1H
0.20 - I
0.15 -
0.10 -
0.05 —
7.6-15.
0.00 — . 2 C',"
0.0 1.0 10.0 100.0
w(kPa)

Figure 3. Effects of tillage on air-ﬁlled porosity at 0 to 7.6 cm and 7.6 to 15.2
cm depths for the Kalamazoo loam soil sampling on April 22, 1992.

f. (m3 m'3)

51

 

0.35 -*

0.30 -

0.25 -

0.20 -

0.15 -

0.10 -

0.05 -

0.00
0.35 —

0.30 e

0.25 -

0.20 -

0.15 —

0.10 ‘1

0.05 -

 

0.00

H Manure
l—l No-manure I

 

H ChISGI pIOW I
H No-tillage
H Ridge till I

 

 

I I I

0.0 1.0 10.0 100.0

Figure 4.

.‘V (KW. . .
Effects of manure history and tillage on air-ﬁlled porosrty at 0 to 7.6

cm depth for the Kalamazoo loam soil sampling on November 12,
1993.

CHAPTER 2
Nitrate-Nitrogen in Stratiﬁed Soils under Variable

Tillage, Chemical Input, and Manure History

Conservation tillage systems are characterized by their alteration of the
physical, chemical, and biological properties of soils. Beneﬁts from adoption of
conservation tillage have historically focused on decreased soil erosion and decreased
sediment and contaminant delivery to surface water (Baker, 1987). In recent years,
however, increased emphasis has been placed on evaluating the impacts of
conservation tillage on groundwater quality. Changes in soil porosity and pore
geometry associated with conservation tillage signiﬁcantly affect water inﬁltration,
runoff, and evaporation (Grifﬁth et a1. , 1986), such that water losses by deep
percolation in some conservation tillage systems may exceed that in conventionally
plowed systems. A number of investigators have suggested that greater inﬁltration
and permeability of soils managed under conservation tillage may increase the
potential for groundwater contamination from agricultural chemicals (Baker and
Laﬂen, 1983; Donigian and Carsel, 1987; Edwards et al., 1988; Helling, 1987;
Wagenet, 1987). Tyler and Thomas (1979) and Thomas et al. (1973) attributed

increased N leaching in no-tillage to macroporous ﬂow, while Angle et a1. (1993)

52

53

showed that the use of no-tillage cultivation may reduce the leaching of nitrates
beyond the crop root zone. Ridge till, as an important conservation tillage system, is
often used as a soil management tool to improve the plant root environment. Ridge
surface conﬁguration is a more favorable water and temperature environment for early
spring plant growth (Buchele et a1. 1955; Burrows, 1963), provides better residue
management for erosion control (Radke, 1982), and results in increased root
development from controlled wheel trafﬁc (Bauder et a1. , 1985) compared with ﬂat
surfaces. Quantitative studies on the direct effects of ridge till system on N leaching
are limited. Conclusive studies on the dynamics of the leaching process, as affected
by ridge till, have not been reported.

Soil proﬁle stratiﬁcation of nutrient and organic matter in conservation tillage
systems is well documented (Thomas, 1986). Smucker (personal communieation)
reported root stratiﬁeation responses in corn to tillage and soil morphologic
differences in soil horizons in a Kalamazoo loam soil (Typic Hapludalf, ﬁne, loamy,
mixed, mesic). Their data suggested that differences in pore size and continuity
between adjacent horizons results in stratiﬁcation of water and nutrients, to which the
plants respond by proliferation at horizon boundaries. It would appear that soil
morphologic changes at horizon boundaries will regulate, to some extent, water
movement and the persistence and fate of N in soils. Therefore, the combined effects
of conservation tillage and soil proﬁle stratiﬁcation will regulate the fate and
movement of N in soils.

While fertilizer N has been implicated in N 0,-N contamination of

54

groundwater, other sources of N can also be responsible. Applications of animal
wastes have been reported to increase concentrations of N03-N below the rooting
zone (Liebhardt et al., 1979; Meek et al., 1974; Olson et al., 1982; Haghiri et al.,
1978). The interaction of tillage systems and manure have not been thoroughly
examined and tested.

This study evaluated role of conservation tillage systems, chemieal inputs, and

manure history, in relation to soil stratiﬁcation, in regulating the fate of N in soils.

MATERIALS AND METHODS

Soil proﬁle inorganic N and soil solution N were measured as part of a study
designed to evaluate the effects of tillage, manure history, and chemieal inputs on
corn and soybean grown in rotation at the Kellogg Biological Station, Hickory
Comets, Michigan, over the period 1990 to 1993. The soil was a Kalamazoo loam
(Typic Hapludalf, ﬁne loamy, mixed, mesic) underlain by coarse glacial outwash
parent material, with an aquifer present within 10 m. The experiment was described
in detail in Chapter 1. Brieﬂy, the study consisted of two manure history treatments
(with and without), three tillage treatments (chisel plow (CP), no-till (NT), and ridge
till (RT)), and two chenrieal input levels (high (HI) and low (LI)). The treatments
were arranged in a randomized complete block strip-plot design with four replications,
with a split plot, with manure as the strip and tillage and chemical input as the split
plot treatments. 0f importance to this study was the application of 140 kg N ha“ of

fertilizer in the HI treatments compared to none in the L1 treatment. Manure

55

applications were made from 1981 to 1988 at an approximate rate of 22 to 27 Mg ha“1
(Bronson, 1989). Manure applications ceased after 1988 in order to evaluate the
effects of manure history on soil N.

Composite soil samples were taken in the spring and fall for analysis of N03-N
and NIL-N. Spring soil samples were taken after N fertilization in 1990 but prior to
N fertilization in 1991 to 1993. Two 5 cm diameter cores were collected from the
center portion of each plot to a depth of 100 cm at increments of 0 to 5 cm, 5 to 15
cm, 15 to 30 cm, 30 to 45 cm, 45 to 60 cm and 60 to 100 cm. Soil samples were
also collected above and below the horizon contacts of the Ap/Bt and the Bt/ C
horizons and to a depth of 50 cm below the Bt/C contact (Figure 1). Two samples
from each plot were mixed and combined into a single sample at each depth. Soil
samples were air-dried and ground to pass through a 2 mm diameter sieve. Ten g of
ground soil were extracted with 100 ml of 1.0 M KCl, shaken for 1 hr, and ﬁltered
through Whatrnan #2 ﬁlter paper. The ﬁltrate was analyzed colorimetrically for NO,-
N and NIL-N using a Latchet injection ﬂow analyzer.

Ceramic cup solution samplers were installed in the crop row position of the
CP and NT in both manure treatments, but only in the HI treatments. In the ridge
till treatment, samplers were installed in the row and between row for all chemical
input and manure treatments. Samples of solution were taken approximately twice a
month, depending on soil moisture content. A vacuum was applied to the sampling
tube using a hand pump, the tube sealed from the atmosphere, and the soil solution

withdrawn the next day.

56

Inorganic N budgets were calculated in order to estimate the potential for N0,-
N leaching (Meisinger and Randall, 1991). Inorganic N balance (N,) is based on the
difference between N“ and NM , adjusted for the change in soil N (AN.). For
our study, N, was calculated as the difference between inorganic N“ from fertilizer
and precipitation and NM taken as the sum of N in the grain, stover, and roots.
The value of AN ,, is dominated by the change in soil NO,-N because soil NIL-N
levels were low and change little over the long term (Meisinger and Randall, 1991).
In this study, AN,t = N”, - th, where Ne... is soil N03-N content at the end of the
analysis season and Nb... is soil N03-N content at the beginning of analysis season.
Nitrogen input from precipitation was estimated as the seasonal precipitation times an
estimated average N content of 2 mg N L" precipitation (Meisinger and Randall
1991). Estimated N inputs from precipitation for the period 1990 to 1993 ranged
from 12tolSngha"inthegrowingseasonand6to16ngha“duringthe
fallow season (Table 1). Nitrogen in the root was calculated as 20 96 of that in the
grain plus shoot (Pierce at e1. 1991). The N, for over winter fallow period was
calculated as AN‘ between the fall sampling following corn and the spring sampling
preceding soybean planting. The N, term is an aggregation of all remaining
components of the N cycle, including net mineralization, denitriﬁeation, volitalization,
leaching, runoff, and N ﬁxation, and is used here as an indicator of the potential for
nitrate leaching. If N, is positive, the potential for N loss by leaching is considered
high, although other mechanisms besides leaching could account for N... Overwinter,

however, N losses are most likely attributable to leaching since soil temperatures are

57

low. A negative N, is indicative of high net N mineralization and a low potential for
leaching.

Soil volumetric moisture content (0) was monitored using time domain
reﬂectometry (TDR) for all tillage and manure treatments in 1991 and 1992, in the
crop row for all tillage treatments and additionally in the midrow for the RT treatment
(Figure 1). The TDR probes consisted of two parallel steel rods (4.8 mm diameter),
placed 50 mm apart. Two probe pairs were inserted vertically for depths of 0 to 15
cm, 0 to 30 cm, and 0 to 75 cm, with each probe placed a distance of 10 cm from the
adjacent probe. The TDR readings were taken weekly during the growing season.
Volummetric soil moisture content was calculated using Topp’s equation (Dalton,
1992).

The analysis of variance was performed using general linear model procedures
(SAS Inst. , 1990). Soil proﬁle NO,-N and NIL-N were analyzed for each depth and
date separately. Soil solution N03-N and NI-L-N were analyzed for each date
separately. Mean differences were determined using a least signiﬁcant difference

(LSD) at the 0.05 level of probability.

RESULTS AND DISCUSSION
The interaction of N O,-N between manure, chemical inputs, and tillage was
limited to three occurences. In the fall of 1990, at the 5 to 15 cm depth, NO3-N was
higher in the manure under low chemical input, but lower under high chemical input.

In May of 1991, under low chemical input, NO,-N was lower in CF than other tillage

58

systems but higher in CP under high chemical input. However, since there were few
interactions among manure history, tillage and chemical input levels, and those that
were signiﬁcant were of minor importance, only the main effects will be discussed
relative to soil N. Additionally, the amounts of exchangeable NI-L-N in soil were low
and relatively constant at all sampling dates. Therefore, NIL-N has not been

discussed.

MANURE HISTORY

Manure generally increased proﬁle N O3-N content to a depth of 60 cm in the
spring in all four years following soybeans, although differences were usually less
than 1 g rn'3 below 5 cm (Figures 2, and 3). However, manure increased NO3-N
only in the surface following corn in 1991 and 1992 but not 1993 (Figure 4). The
higher NO,-N in the surface 5 cm indicates greater mineralization in the manured than
non-manured soil even 5 years after manure applications ceased. Nitrate-N was
highest following corn in 1991 than in other years, reﬂecting the high NO3-N
measured in December, 1990 (Figure 5). The effect of manure on soil NO3-N was
variable following corn (Figure 5). In 1990, residual N O,-N was relatively high in
the 30 to 60 cm depth and was higher for the non-manure than the manure treatment
(Figure 5). The higher residual NO,-N was due to a poor corn crop, but the reason
for the higher NO3-N in the non-manured soil was not apparent, as there were no
differences in corn yield (Chapter 1). In 1992, NO,-N was considerably higher

throughout the soil proﬁle in the manured treatment, as much as 2 g N m". There

59

were mixed but minor differences due to manure in NO,-N in December of 1991 and
1993, although manure was almost 2 g N rn'3 higher in the 0 to 5 cm of the manured
treatment in 1993. In comparing Figures 4 and 5, it would appear that residual NO,-
N was leached by spring. Soil N O3-N in December following soybeans was not
affected by manure history in 1992 (Figure 6).

Soil solution NO,-N under corn was highly variable in 1991 and 1992 (Figure
7). The only measurable differences between treatments occurred on the 25 July,
1991 and 19 August, 1992, and these were reversed relative to manure effects. The
weather in 1991 was warm and moist and ideal for N mineralization (favoring the
manured treatment) while 1992 was cold and wet. Prior to fertilization, soil solution
NO,-N was low prior to N fertilization, which dramatically increased soil solution
NO,~N. In either case, the potential for NO3-N leaching was high in both years until
mid August when the corn crop had depleted soil N reserves during the grain ﬁll
period.

In 1990, a year with high rainfall and low crop yields, less N was taken up by
the crop, and the potential for NO3-N leaching was high in all treatments (Figure 8).
The N, was 26.2 kg ha" higher in the manure treatment than in the no—manure
treatment. In 1991, 1992 and 1993, when crop uptake N exceeded fertilizer
applieation, the growing season N, was negative, indicating that considerable N was
mineralized to supply the N needs of corn. Net mineralization was at least 45, 29
and 18 kg ha" higher in the manure treatment than in the no-manure treatment in

1991, 1992 and 1993, respectively. Therefore, the residual effects of manure were

6 0
evident 5 years after applications ceased.

The NO,-N loss over winter was highest under no-manure in 1990, due to the
higher proﬁle NO,-N (Figure 8). Because of the high N uptake in the 1991 growing
season and lower soil nitrogen content after harvest, N, over winter was very low,
with no differences between manure treatment. Over winter losses in 1992-93 were
considerably higher in the manured treatment, largely because of the higher soil
proﬁle NO,-N in the manured treatment in December, 1992.

In general, the effect of manure was to increase net mineralization but at the
cost of increasing the potential for NO,-N leaching, although this was not consistent
in all years. The effects of manure were still evident to a depth of 1 m 5 years after

manure applications ceased.

CHEMICAL INPUT

The direct effects of N fertilization were measured in 1990 when soils were
sampled after application (Figure 2). Concentrations of NO,-N were considerably
higher in the HI than LI treatment in the 0 to 30 cm depth increments but not below.
In 1991 to 1993, NO,-N in HI was not different than LI following soybeans and
slightly higher in the surface 5 cm in 1993 following corn in soil proﬁles sampled in
the spring prior to planting (data not shown). There were, however, large
differences due to input treatment in December of each year, with HI having much
higher NO,-N below 30 cm to a depth of 100 cm than LI (Figure 9). Since few

differences were found in the spring soil proﬁle sampling, the residual NO,-N in H1

61

was apparently leached over winter. The high leaching potential for the HI treatment
was also very apparent in the soil solution samples in both 1991 and 1992 (Figure
10). The LI solution concentrations of NO,-N were low all season (<15 mg L")
and represent baseline levels of NO,-N in soils under no fertilizer application. The
N, was positive in 1990 due to the poor corn yield and higher for HI than L1, as
would be expected (Figure 11). In 1991 to 1993, growing season N, was negative,
with LI showing some indication of increased net mineralization in an attempt to
supply the corn crop with N. The over winter N, were higher for HI than LI only in
1990. However, the calculation of over winter N budget would underestimate N,
since any N nrineralized in the spring would reduce the apparent N losses. Soil NO,-
N in the fall following corn was lower than following soybeans (Figure 6 and 9)
indicating a release of N from the soybeans and a slight build up NO,—N in the fall.

Inputs of N fertilizer, as would be expected, resulted in more N in the soil
proﬁle, higher soil solution N concentrations, and higher NO,—N leaching potential
than no fertilizer N input. The lack of difference between soil proﬁle NO,-N in the
spring between HI and LI conﬁrms that residual soil NO,-N was leached over winter
on this soil. The large differences soil solution N O,-N between HI and LI at the
base of the soil proﬁle indicates that leaching occurred in HI during the growing

season as well.

TILLAGE

In June, 1990, following N fertilization, tillage had little effect on soil proﬁle

62

NO,-N, although RT was higher in the 5 to 15 cm depth (Figure 2). In the spring of
1991 and 1992, NO,-N in CP was often higher than RT and NT following either
soybeans or corn (Figure 12 and 13). In May 1991, NO,-N was higher following
corn than soybeans, after a year of low corn grain yields and high residual NO,-N in
1990, and differences between tillage treatments were greater. In May 1992,
differences between tillage systems were greater following soybeans than corn,
reﬂecting high corn grain yields in 1991. In May of 1993, following soybeans, NO,-
NinCPwashigherintheS to30cmdepthandlowerin the30to45 and45 t060
cm depths than in NT and RT, while following corn, NO,—N was higher in GP to a
depth of 45 cm. In the December, NO,-N following corn was generally higher in CP
than NT and RT, and generally the lowest in RT in all but 1993 (Figure 14).
Following soybeans in 1992, N O,-N was higher than following corn and higher in NT
at 15to45 cmandhigherinCPthanRTinSto 15 cm (Figure6). Thisreﬂectsthe
release of N by soybeans in the fall and the higher yields in NT than the other
treatments. Ridge till had signiﬁcantly higher soil solution NO3-N in both years,
particularly after N fertilization, than the other tillage treatments (Figure 15). The
lower soil proﬁle NO,-N and higher solution NO3-N indicate that the potential for
NO,-N leaching during growing season was higher in RT than in CP or NT.

In 1990 growing season, RT lost about 60 kg N ha'1 compared to 40-and 10
kg N ha" for NT and CP, respectively, indicating that leaching occurred during the
growing season (Figure 16). In 1991, when crop N demand was high, CP seemed to

release more N due to soil surface disturbances by chiseling and enhancement of

II”:

for

wt

NI

min

80

63

microbial activities. Net mineralization rates for CP were 53 kg N ha" higher than
RT and 35 kg N ha" higher than NT. Nitrogen balance was not different between
tillage treatments in 1990. Again in 1993, mineralization was higher for the CP than
NT, but there was no difference for RT. In the winter of 1990 to 1991, N, was 13
to 18 kg ha'1 and there were no difference between tillages. The following winter, N,
was 12 kg ha" for chisel plow, as compared to 2 kg ha'1 for NT and negative value
for RT. Nitrogen balance was 11 to 14 kg ha'1 for all three tillage systems in the
winter 1992 to 1993. The negative over winter N, in 1991 would also indieate that
NO,-N was lower in RT by fall sampling.

We might expect that the row position under ridge till may leach more
nitrogen during rainfall event due to accumulation surface water. This was not
observed (data not shown) because the samplers in-row and mid-row were only 36
cm apart. Samples collected from both sampler position was mixed from ridge and

valley, and we could not distinguish between the two position by this method.

SOIL MOISTURE

There were no differences in soil volumetric moisture content (0) due to
manure history or chemical input. The seasonal distributions of 0 for three tillage
systems are given in Figures 17 and 18 for 1991 and 1992, respectively. In 1991, RT
had lower 0 than the CP at both depths during most of the growing season. The 0 in
NT was higher than in RT frequently but less often than CP in 1991. There were no

differences in 0 between NT and CP in either year. In 1992, 0 in RT again was

64

lower than CP at the 0 to 15 cm depth between 3 June and 3 August. There were no
differences in 0 due to tillage at 15 to 30 cm depth in 1992, with the exception of
higher 0 in CF than NT on 8 September. There was no differences in 0 due to tillage

at 30-75 cm depth in either year.

NITRATE-N STRATIFICATION

Nitrate-N stratiﬁcation was expressed as a stratiﬁcation index (SI), deﬁned as
the ratio of soil N O3-N concentration in upper to lower layer. Stratiﬁcation index
values larger than 1 indicated that soil NO3-N had accumulated in the upper layer of
the horizon contact. The degree of stratiﬁcation of N O,-N was minimal under
manure and chemical input (Table 3). Most differences in SI were related to tillage,
with mixed results. The greatest stratiﬁcation was measured in NT in the spring of
1990 after N fertilization, at which time the NT had an SI of 1.6 and CP and RT
were less than 1.0. The S1 was higher for CP in the fall in 1990 and 1991. In
general, however, the degree of stratiﬁcation was weak, probably due to the fact that
most soil samples were take prior to fertilization in the spring and after harvest.

Based on these data, stratiﬁcation of N03-N in this soil was minimal.

SUMMARY AND CONCLUSION
Soil proﬁle and soil solution NO,-N were evaluated along with N balance in
response to manure history, tillage system, and chemical input levels in a com-

soybean rotation. There were no interactions between treatments over a four year

65

period. The main effect of manure was to increase residual proﬁle N O,-N , soil
solution N 0,-N , and N, and thereby increase the potential for NO3-N leaching. This
study indicates that the residual effects of manure history were evident in increased N
mineralization 5 years after manure application ceased.

Nitrogen fertilizer was the major source contributing to N O3-N leaching,
especially in low yielding years when crops could not utilize additional N. High
chemieal input treatments potentially lost more than 50 kg ha" nitrogen in the 1990
growing season while potential losses in L1 were 18 kg ha" and contributed to
increased over-winter soil N loss. Baseline levels of NO,-N at the base of the soil
proﬁle, represented by levels under LI, were near 15 mg N L" in soil solution in the
spring and declined to below 10 mg N L" during the growing season. Fertilizer
elevated concentrations to > 25 mg N L" soon after N application. Thus, the 10 mg
N L" EPA standard would be exceeded in the soil solution at the base of the soil
proﬁle even under L1 in the spring. However, even though solution N O3-N was
below 10 mg N L" under LI during the growing season, soil NO3-N content was too
low to meet the N requirement of corn.

The CP had consistently higher soil proﬁle N03-N than NT and RT in spring
and fall. This suggests that the disturbed soil surface under CP enhanced
mineralization in early spring. The higher NO3—N for CP in fall contributed higher
N, over winter. Ridge till had consistently lower proﬁle NO3-N but high soil solution
NO3-N, indicating RT had the highest potential for NO3-N leaching during the

growing season. Ridge till had consistently lower 0 than other tillage systems in the

 

row, indi
mOVCmeI

whim.

66

row, indicating water movement in the valley of the nridrow. The preferential
movement of water in the ridge valley may explain the lower 0 and higher NO,-N in
solution.

There was little evidence of proﬁle stratiﬁcation of N 0,-N at horizon
boundaries. This was in part related to the sampling times occurring before N
application and after harvest. Overall, the more intensely managed the system, that is

manure, chemicals and chisel plowing, the higher the potential for N O,-N leaching.

LIST OF REFERENCES

Angle, J. S., C. M. Gross, R. L. Hill, and M. S. McIntosh. 1993. Soil nitrate
concentration under corn as affected by tillage, manure, and fertilizer
application. I. Environ. Qual. 22:141-147.

Baker, I. L., and Laﬂen. 1983. Runoff losses of nutrients and soil from
ground fall-fertilized after soybean harvest. Trans ASAE 25 :344-348.

Bauder, J.W., G.W. Randall, and Schuler. 1985. Effects of tillage with
controlled wheel trafﬁc on soil properties and root growth of corn. J.
Soil Water Conserv. 40:382-385.

Bronson, J. A. 1989. the effect of tillage system on corn production and soil
properties on a Kalamazoo Loam. M.S. Thesis. Michigan State
university. East Lansing, MI.

Buchele, W.F., E.V. Collins, and W.G. Lovely. 1955. Ridge farming for soil
and water control. Agric. Eng. 36:324-329.

Burrows, W.C. 1963. Characterization of soil temperature distribution from
various tillage-induced microreliefs. Soil Sci. Soc. Am Proc. 27 :350—
353.

Dalton F. N. 1992. Development of time—domain reﬂectometry for measuring
soil water content and bulk soil electrical conductivity. p. 143-167 in
G.Clarke Topp, W. Daniel Reynolds, and Richard E. Green (eds.)
Advances in measurement of soil physical properties: Bring theory into
practice. ASA, CSSA, and SSSA, Madison, WI.

Donigian, A.S., Jr., and R.F. Carsel, 1987. Modeling the impact of
conservation tillage practices on pesticide concentrations of ground and
surface water. Environ. Topical. Chem. 6:241-250.

Edwards, W.M., L.D. Norton, and C.B. Redmond. 1988. Characterizing
nracropores that affect inﬁltration into non-tilled soils. Soil Sci. Soc.
Am. J. 53:483-487.

Grifﬁth, D.R. and , J.V. Mannering , and J.E.Box. Soil andmoisture
management with reduced tillage. p. 19-58. In M.A.Sprague and
G.B.Trip1ett (eds) No-tillage and surface -Tillage Agriculture -The
Tillage Revolution. John Wiley & Sons, New York.

67

68

Haghiri, F., R.H. Miller, and T.J. Logan. 1978. Crop response and quality of
soil leachate as affected by land application of beef cattle waste.
J.Environ. Qual. 7:406-412.

Helling, C.S 1987 ; Effects of conservation tillage on pesticide dissipation. p.
179-187. In T.J. Logan et al. (ed.) Effects of conservation tillage on
ground water quality: Nitrates and pesticides. Lewis Publ. Chelsea, MI.

Liebhardt, W. C., C. Golt , and J. Tupin. 1979. Nitrate and ammonium
concentrations of ground water resulting from poultry manure
applications. J. Environ. Qual. 8:211 ~215.

Meek, B.D., A.J.Mackenzie, T. J. Donovan, and W. F. Spenser. 1974. The
Effect of large applications of manure on movement of nitrate and
carbon in an irrigated desert soil. J. Environ . Qual. 3:235 - 258.

Meisinger, J. J. and G.W. Randall. 1991. Estimate nitrogen budgets for soil-
crop systems. p.85-124. In R. F. Follott, D. R. Keney, and R. M.
Cruse (ed.) managing nitrogen for groundwater quality and farm
proﬁtability. ASA, Madison, WI.

Olson, R. V., R. V. Terry, W. L. Powers, C. W. Swallow, and E. T.
Kanemasee. 1982. Disposal of feedlot - lagoon water by irrigation

Brown grass: 11. Soil accumulation and leaching of nitrogen. J.
Environ. Qual. 11:400 - 405.

Pierce, F.J., M. J. Shaffer and A. D. Halvorson. 1991. Screening procedure
for estimating potentially leachable nitrate-nitrogen below the root zone.
p.259-283. In R. F. Follott, D. R. Keney, and R. M. Cruse (ed.)
managing nitrogen for groundwater quality and farm proﬁtability.

ASA, Madison, WI.

Radke, J .K. 1982. Management early season soil temperatures in the
northern Corn Belt using conﬁgured soil surfaces and mulches. Soil
Sci. Soc. Am. J. 46:1067-1071.

SAS Institute. 1990. SAS/STAT user’s guide. Version 6. SAS Inst., Cary,
NC.

Thomas, G. W. 1986. Mineral nutrition and fertilizer placement. P. 93 -
116. In M. A. Sprague and G. B. Triplett (eds) No - tillage and
Surface - Tillage Agriculture - The Tillage Revolution. J ohnn Willey
& Son, New York.

69

Tyler, D. D. and G. W. Thomas. 1979. Lysimeter measurements of nitrate
and chloride losses from conventional and no - tillage corn. Agron. J.
74:823 - 826.

Wagenet, R.J. 1987 . Processes inﬂuencing pesticide loss with water under
conservation tillage. p. 189-204. In T.J. Logan et al. (ed.) Effects of
conservation tillage on ground water quality: Nitrates and pesticides.
Lewis Publ. Chelsea, MI.

 

Tat

70

Table 1. Precipitation and estimated precipitation nitrogen input in growing season
and fallow period in 1990, 1991, 1992 and 1993.

 

 

 

May 1 - November 30 December 1 - April 30
Precipitation N -input Precipitation N-input
(mm) (kg ha“) (mm) (kg ha")
1990 714 14.2 837 16.6
1991 691 13.8 347 6.9
1992 599 12.0 556 10.7

1993 591 11.8

 

71

Table 2. Stratiﬁcation index for the Ap/Bt and Bt/ C horizons in the Kalamazoo Loam
soil over 1990 to 1993.

 

 

 

 

 

 

 

Manure 0.9 1.1 1.0 l 1 1.1 1.0 1 1
Non-manure 1.3 1.0 1.1 l l 1.1 1.1 10 10
LSD (0.05) NS NS NS NS NS NS NS NS
High Input 0.9 1.1 1.0 1 1 1.1 1 1 1.0 10
Low Input 1.3 1.1 1.0 1 1 1.0 1.1 10 10
LSD(0.05) 0.3 NS NS NS NS NS NS NS
Chisel plow 0.8 1.1 1.1 1.1 1.1 1.2 1.1 1.0
No—tillage 1.6 1.1 1.0 1.0 1.0 1.1 0 1.1
Ridge till 0.9 1.0 1.0 1.2 1.1 1.0 0 9 1.1
LSD(0.05) 0.3 NS NS 0.1 NS NS NS 0.1
Ball
Manure 0.9 1.2 1.1 1.1 1.0 1.2 1.0 1.1
Non-manure 1.0 1.1 1.0 1.1 1.1 1.0 1.1 1.1
LSD (0.05) NS NS NS NS NS NS 0.1 NS
High Input 1.0 1.2 1.1 1.2 1.0 1.1 1.0 1.1
Low Input 1.0 1.1 1.0 1.0 1.0 1.1 1.1 1.0
LSD(0.05) NS NS NS 0.2 NS NS 0.04 NS
Chisel plow 0.9 1.2 1.2 1.3 1.0 0.9 1.0 1.1
No-tillage 1.0 12 1.0 1.0 1.0 1.1 1.1 1.1
Ridgetill 1.0 1.0 1.0 1.1 1.0 1.2 1.0 1.1
LSD(0.05) 0.1 0.2 0.1 0.2 NS NS 0.04 NS

 

'72

 

Proﬁle posltlon Sampling depth

 

AbOVO AP/BI :::::::::::::::::::: 15 cm
Below 3th
30 cm
45 cm
Above Bl/C 60 cm
Below mm
100 cm

 

Glacial
outwash

   

Loam

 

Clay loam

Figure 1. Illustration of soil proﬁle horizons, soil sampling depths, soil solution
sampler installation, and TDR placement for the Kalamazoo loam soil
at Hickory Corners, MI.

73

 

 

 

  
  

 

 

 

 

 

LSD (0.05)
20 - June 1990
40 — ll
60 — H
80 -
. Manure
100 - u
I lie-manure
O
20— June,1990
40 4
E 60 —
ﬁ
8 80 -
100 _ . High input
0 I Low input
20 - June 1990
40 -‘
60 -
80 '-
. Chisel plow
100 - I I No-tillage
‘ Ridge till
I l T l l n 1‘ l
O 20 40 60 80 100 120 140 160
NOa-N (9 m3)

Figure 2. Soil proﬁle NO,-N as affected by manure history, tillage, and chemical
input following corn for the Kalamazoo loam soil for the June, 1990
soil sampling date.

74

 

May, 1991
20 -

40-
60— H

80 -
100 _ I Manure H

I No-manure LSD IO-OSI
May, 1992 H

 

20 -
40 -
60 -+ H
80 -
100 -

Depth (cm)

 

May, 1993 '—1
20 -

40 -
60 - H
80 -

100 -

 

 

 

I I I I I I I I

0 2 4 6 8 10 12 14 16 18
NOa-N(gm*3)

Figure 3. Soil proﬁle NO3-N in the spring as affected by manure history
following soybeans in the previous year for the Kalamazoo loam soil
for the period 1991 to 1993.

75

° May, 1991 1 a

20-

 

 

40-1
60-

80 —
100 _. . Manure

I No-rnanure LSD (0.05)
May, 199 .

 

 

 

20 -
40 -
60 -
80 e
100 -

Depth (cm)

 

 

 

May, 1993
20 -

40 -
60 -
80 -
100 -

 

 

 

I I I I I I I I I

I
0 2 4 6 8 10121416182022
Noa-N(gm-3)

Figure 4. Soil proﬁle NO,-N in the spring as affected by manure history
following corn in the previous year for the Kalamazoo loam soil for the
period 1991 to 1993.

 

20‘-
40-e
60-
80'-
100'-

ll Nkrnmmnure

 

/

76

 

H LSD (0.05)

'_.'

l-—-I
H

H

Dec 199C

 

.5.
9..

Dec 1991

 

 

100 -

Dec 1992

 

20 -
40 -
60‘-
80 -
100‘-

 

 

Figure 5 .

 

Dec 1993
I

16

l I r
10 12 14

NOa-N (9 m")

18

Soil proﬁle NO3-N in the fall as affected by manure history following
(murmrﬂwlhhmmumdmunsﬁtmrﬂwreﬁuiu%mwol9gl

77

 

 

 

 

 
  

 

 

LSD (0.05)
20 -— Dec 1992
:5: 40 -
g 60 —
3 so -—
O
100 _ Manure
- No-manure
0
20 - Dec 1992
40 -
60 -
80 —
100 — ' Hizh input
0 I Low input
Dec 1992
20 - '
40 -
60 -
80 -
. Chisel plow
100 ‘ . No-tillage
A Ridge till
I I I I I I I I I I I

 

0 2 4 6 810121416182022
N03-N(gm4)

Figure 6. Soil proﬁle NO3-N as affected by manure history, tillage, and chemical
input following soybeans for the Kalamazoo loam soil for the
December, 1992 soil sampling date.

78

 

40 1991 . Manure
35 _ I Non-manure

30-‘
25-1
20-

Nos-N (mg L")

“5-

 

 

ﬂ)-

 

 

 

5 I T I I I I I i
7 July 25 July 21 Aug. 10 Sept 7 Oct.

40

 

1992
35-

so —
25 - I"
20 d
15 ~

No3-N (mg L")

 

ﬂ)-

 

 

 

5 I I I I T I I
8April away 20 July 19 Aug. 31 Aug. SSept.

Figure 7. Soil solution N03-N in response to manure history sampled at the Bt/ C
horizon contact of a Kalamazoo loam soil during the 1991 and 1992
gmwmgumwm

100

 

 

 

 

 

 

 

 

 

 

 

 

50 _ Growing Season
9 , Ila e e
g LSD (0.05)
g -50 —
Zn
-100 —
-15O - :I Manure
No-manure
’200 1990 1991 1992 1993
25
Over Winter
20 — _
To 15 —
.c
O)
as
Z" 10 ‘
5 _ I—I
, ﬂ
1990 1991 1992

Figure 8. Nitrogen balance (N.) for the growing season and over winter period as
affected by manure history over the period 1990 to 1993.

 

O
20-
40-
60—
80-

LSD (o. 05)

 

 

 

 

 

100
0

High input

I Low input

:7?

 

20 -
40 d
60 -
80 -
100 -

0

Dec 1991

 

20 J
40 —
so —
so —
1oo —

0

Depth (cm)

I——I

Dec 1990
l—I
Z I

Dec 1992’

 

 

20 ~
40 ~
60 -
80 ~
100 -

 

I—I

w

 

Dec 1993
l l

 

Figure 9.

Soil proﬁle No,-N in

I I I

I

8 10 12 14 16 18

N03-N (9 me)

the fall as affected by chemical input levels

history following corn for the Kalamazoo loam soil for the period 1990

to 1993.

81

 

 

 

 

 

 

 

 

 

70
m —
1991 ' mill in?“
:5‘ 5° ‘ I Low input
.1
3 4o —
z
5» 3° ‘
z
20 - I
10 '1
0 I I I I I I I I
7 July 25 July 21 Aug.10 Sap. 70d.
:1
o
E
z.
n
O
z
0 I I T I I I I

 

 

8 April 8 May 20 July 19 Aug. 31 Aug. 5 Sept.

Figure 10. Soil solution N O3-N in response to chemieal input levels sampled at the
Bt/C horizon contact of a Kalamazoo loam soil during the 1991 and
1992 growing season.

82

 

1oo
Growing Season

%
/
%

A

50-

 

 

LSD (0.05)
-50 —I

\\

Nb (kg ha”)
\\

-100 -

 

_1 50 _ :1 High input
W Low input

 

 

~200

 

1990 199 1 1992 1993

 

25 _ Over Winter
20 —
15 —
1o —

3‘ l_l

m
-5 —
-10 -

-15 —

 

 

Nb (kg ha")

 

 

 

 

 

1990 1991 1992

Figure 11. Nitrogen balance (N,) for the growing season and over winter period as
affected by chemical input levels over the period 1990 to 1993.

83

May, 1991+——+

l———I

 

 
  
 
 
 

20 —
4O -
60 -
80 -
100 -1

LSD (0.05)

I Chisel plow
I N o-tillage

A Ridge till

 

H
20 ﬂ May, 199

40 -
60 -
80 -
100 —

Depth (cm)

 

May, 1993

 

20 '1
4O -
60 —
80 —
100 -1

 

 

 

I I I I I I I I I I I

0 2 4 6 810121416182022
N03-N(gm'3)

Figure 12. Soil proﬁle NO3-N in the spring as affected by tillage systems
following corn in the previous year for the Kalamazoo loam soil for the
period 1991 to 1993.

AEOV CuQmo

Figure

84

 

 

 

 

 

 

 

 

May, 1991
20 ~ ' '
4o —
so —
so —
I Chisel plow
100 - I lie-tillage
o A Ridge till LSD (0.05).
May, 1992
20 a ‘
’g‘ 40 a / I I
a I——-I
g so
8 so —
100 ~ I——I
0
May, 1993
20 —
40 a
so ~
80 -
1oo —
I I I I T I I I
o 2 4 6 81012141618
NO3-N (g m-3)

Figure 13. Soil proﬁle NO3-N in the spring as affected by tillage systems
following soybeans in the previous year for the Kalamazoo loam soil
for the period 1991 to 1993.

 

 

 

 

 

 

 

 

 

 

0 85
(0.05)
20 *
I—-———-I
4° ‘ I————I
60 -
so _ I Chisel plow
100 _ I No-tillage
A Ridge till Dec 1990
20 -
I—I
4o — ,_a
60 — I——|
A so —
E
100 — I—i
9’ Dec 1991
5 0
a.
o _ I—I
Q 20 H
40 -
60 -* i—l
80 -
100 ~
0 Dec 1992
20 —
40 -
60 -‘
80 -
100 -
Dec 1993»
I I I I I I I I
0 2 4 6 8 10 12 14 16 18
NO3-N (9 m3)

Figure 14. Soil proﬁle N03-N in the fall as affected by tillage systems following
com the Kalamazoo loam soil for the period 1991 to 1993.

86

 

1991

Noa-N (mg L")
8
l

 

20-

10-

 

 

 

 

 

0 I I I I I I I
7 July 25 July 21 Aug.1o Sept. 7 Oct.

60

 

I Chisel plow
1992 I No-tillage

' 50 I ‘ Ridge till

4o-
aoa

20-i

No3-N (mg L")

10-1

 

 

 

 

0 I I I I I I
Apil8 Mays July20 Aug.19 Aug. 31 Sept.5

Figure 15. Soil solution NO3-N in response to tillage systems sampled at the Bt/C
horizon contact of a Kalamazoo loam soil during the 1991 and 1992
growing season.

87

 

 

I:I Chisel plow

No-tiuage

W Ridge till

  

Growing Season

 

1991

 

 

 

 

 

 

1993

1 992

1990

 

Over Winter

  

%%%%%%%

  

 

 

 

20-
15-

 

1o —
5 _
o _
-5 _
-10 —
-15

9-2 9: ..z

1991 1992

1990

Nitrogen balance (N,) for the growing season and over winter period as
affected by tillage systems over the period 1990 to 1993.

Figure 16.

88

0.45
I Chisel plow
0_4o _ I No-tilla e
‘ Ridge t

0.35 — 0-15 cm
0.30 —
0.25 -
0.20 -
0.15 —
0.10 -
0.05 -
0.00
0.40 -

 

9 (m3 m4)

 

 

15-30 cm
0.35 -

0.30 —
0.25 ~
0.20 -
0.15 —
0.10 -
0.05 -

0.00 I I I I I I
190 197 201 208 215 223 229 236
Days of year in 1991

9 (m3 m'a)

 

 

 

 

Figure 17. Soil volumetric moisture content (0) as affected by tillage system for
the 0 to 15 and 15 to 30 cm depths ofa Kalamazoo loam soil in 1991.

s9
0'45 I Chisel plow I
0 4o _ I No-tillage
' A Ridge till
I

 

  
  
 
   
 

0.35 -
0.30 -
0.25 -
0.20 -
0.15 —
0.10 -
0.05 -
0.60

0 (m3 m")

LSD (0.05)

O-15 crn

 

0.45 —

0.40 -

0.35 -

6 (m3 m“)

0.30 -
0.25 -
0.20 -
15-30 cm
0.15 I I I I I I I I

147 154 159 166 180 187 197 201 208 215
Days of year in 1992

 

 

 

Figure 18. Soil volumetric moisture content (0) as affected by tillage system for
the 0 to 15 and 15 to 30 cm depths of a Kalamazoo loam soil in 1992.

CHAPTER3

Bromide Movement Related to Tillage and Positions on a Glacial Outwash Soil

Ridge till (RT) is accepted as successful conservation tillage technology for
improving the plant root environment. Ridge till has been shown to accelerate drying
and warming of the seed zone of moderately to well drained soils (Potter et al. 1985 ;
Al-Darby and Lowery 1987). Ridge till systems have been show to achieve yields
equivalent to moldboard plow systems on poorly drained soil (Eckert 1987). In an
experiment of identical nitrogen application amounts for RT and ﬂat plots under 24,
50, and 72 mm of simulated rainfall, Hamlett (1990) reported that the RT
conﬁguration, with placement of NO3-N in the elevated portion of the ridge, could
potentially isolate fertilizer from downward water ﬂow and minimize nitrate leaching.

Ridge till treatments tended to have higher nitrate leaching than no-tillage (NT)
and chisel plow (CP) as evidenced by lower NO3-N in soil and higher solution NO3-N
at the base of the soil proﬁle. Comparing with CP and NT, ridge till had lower
surface soil moisture contents, quicker recharge and depletion soil of moisture content
and lower nitrogen content after crop harvest. Knowledge of soil nutrient
distribution, as affected by RT, will help to identify optimum fertilizer management,

but little work has been completed in this area. To test the conclusion that RT creates

90

91

a higher risk for nitrogen leaching, bromide (Br) was used as a tracer to monitor soil
solution behavior under different tillage systems and row positions. Bromide was
selected as a tracer, because its weak tendency for adsorption would permit
monitoring of water movement through the soil. In addition, the behavior of Br in
soil water systems is similar to that of NO; (Smith and Davis, 1974), and its natural
occurrence in soils is usually limited.

The Burns leaching equation ( Burns, 1975; Scotter et al., 1993), a transfer
function model (Jury, 1982), and the MACRO model (Jarvis et al., 1991) were tested
using the ﬁeld date and natural rainfall in this experiment. Burns (1975) applied a
simple model to derive an equation giving the distribution of surface-applied nitrate
after a given quantity of applied water had passed through the soil proﬁle. Towner
(1983) and Scotter et al. (1993) examined theoretically the equation and derived a
simpliﬁed form.

The Transfer Function Equation (TFE), as a non-mechanistic stochastic model,
was an approach to measure the distribution of solute travel time from the soil surface
to some reference depth. Field comparisons have shown good agreement between
measured and predicted Br concentrations (Jury et al., 1982), and indicate that this
model could be useful as a stochastically-based management model for solute
movement. The most important characteristic of such a model is that it attempts to
simulate spatially-variable ﬁeld processes with only a minimum of input data. But it
is not yet known whether the approach will be satisfactory in vertically non-

homogeneous soils (Addicott and Wagenet, 1985).

92

MACRO is a mechanistic model of non-steady-state transport of water and
solutes in a macroporous soil, developed by Jarvis (1991). The model is deterministic
and considers non-steady-state ﬂuxes of water and solutes in a macroporous, layered
soil proﬁle. The model assumes that the total porosity in each layer is divided into
two components, micropores and macropores, with a speciﬁed boundary water
potential. The hydraulic conductivity at that given soil-water potential must also be
speciﬁed. The model has been successfully tested against ﬁeld leaching
measurements in structured clay soils (Jarvis et al. 1991; Jabro et al. 1994).
However, it is not known how the model simulates different tillage and row positions.

This study (1) evaluated the movement of Br by row position under CP, NT
and RT and within RT as affected by Br placement in the row (ridge) or midrow
(valley); and (2) tested the Burns leaching equation, the TFE of solute transport, and

the MACRO model using ﬁeld data under natural, non-steady state rainfall conditions.

MATERIALS AND METHODS
E. II E .

The fate of Br was evaluated as part of a study designed to evaluate the effects
of tillage, manure history, and chemical inputs on corn and soybean grown in rotation
at the Kellogg Biological Station, Hickory Corners, Michigan, over the period 1990
to 1993. The soil was a Kalamazoo loam (Typic Hapludalf, ﬁne loamy, mixed,
mesic) underlain by coarse glacial outwash parent material, with an aquifer present

within 10 m. The experiment was described in detail in Chapter 1. Brieﬂy, the

93

study consisted of two manure history treatments (with and without), three tillage
treatments (CP, NT, and RT), and two chemical input levels (high (HI) and low
(LI)). The treatments were arranged in a randomized complete block strip~plot design
with four replications, with a split plot, with manure as the main treatment and tillage
and chemical input as the split plot treatments. Only the tillage plots under no—
manure and high chemical input were used in this study.

Two Br transport experiments were performed in 1992 and 1993. The ﬁrst
experiment evaluated the effect of row placement of Br on its transport in soil under
RT. Potassium bromide (KBr) was applied at a rate of 300 kg Br ha" in the row or
in the midrow in 3 replications in 1992 and again in 1993. The area for the row
application was separated from the area for the midrow application to avoid cross
contamination of Br (Figure l) and each year was applied in a different location
within the same 3 replications. The KBr applications were made on 30 June, 1992
and 30 June, 1993, shortly after the ridge was built, to an area of 0.75 by 3 m.

The second experiment evaluated the transport of Br in CP and NT. Potassium
bromide was applied uniformly to an area 2.28 by 3 m (across three rows) in three
replications at a rate of 300 kg Br ha" on 15 June, 1993. In both experiments, KBr
was dissolved in water at a concentration of 500 mg Br L" and was sprayed
uniformly with a hand-held sprayer in three equal applications to insure uniform
coverage.

In the ﬁrst experiment, conducted in 1992 and repeated in 1993, 'soil samples

were taken in the row and in the midrow position for both placement treatments on 16

94

July, 31 August, 29 September in 1992, and 16 April in 1993. In 1993, soil samples
were taken on 15 July, 25 August, 14 September and 15 October. In the second
experiment, conducted only in 1993, soil samples were taken on the CP and NT in
the row and midrow position in 1993 on 1 September, 21 September and 15 October.
Sampling depths were 0 to 20 cm, 20 to 40 cm, and 40 to 60 cm for 1992, with an
additional sampling at 60 to 80 cm for April 1993. At each sampling, the sample
hole was carefully reﬁlled by untreated soil. All plants within the application area
were sampled at harvest and stover and grain analyzed for Br content. Soil Br
concentration was determined by extracting 10 grams of soil with 50 ml of water and
shaking vigorously for 1 hr. Five grams plant tissue samples were extracted with 100
ml water and shaking vigorously for 1 hr. The supernatant was measured for Br
concentration using an Orion bromide ion selective electrode.

Analysis of variance was performed using general linear model in SAS (SAS,
Inst. , 1990). The ridge experiment was analyzed as a randomized complete block
split plot design with 3 replications, with application position (row versus midrow) as
the main plot and sampling position (row versus midrow) as the split. The second
experiment was analyzed as a randomized complete block split plot design with 3
replications, with tillage (CP versus NT) as the main plot and sampling position (row
versus midrow) as the split.
Madﬂah'datinn

Three models were evaluated using the Br data from the above experiments

and daily rainfall, temperature and pan evaporation data obtained from the weather

95

station located at the Kellogg Biological Station. The ﬁrst model uses a modiﬁcation
of the Burns (1975) equation for the leaching of a surface-applied solute (Towner,
1983). The Burns equation is:

Com; 1 2
$4 '1+o,,/' 1—‘oo )

(1)

where C0 is solute input to the soil, COUT is solute leached below depth 2, in a
uniform soil with volumetric water content at ’ﬁeld capacity’ 0., by water application,
I. Towner (1983) analyzed the Burns equation as a solution of the differential
equation for pure convection of solute moving at the average soil water velocity with
no dispersion. He then modiﬁed Equation (1) to the simpliﬁed form used in this

analysis:

Cour
—C0 =exp I—ZM I) . (2,

The second model predicts average solute concentration as a function of depth
and as a function of spatially uniform water application, I, using a transfer function

equation (Jury, 1982) expressed as:

a I (3)
C(z.1)=fo Carl—Io gm 17")!” ’

96

where C (Z, I) is outflow of solute at Z depth and drainage I, and L is the depth of

the outﬂow surface. For the input

CEAFO I S)
C -C I >0 (4)
arr 0
Equation (3) yields the result
COW =l(1+epf (ImUL/ZH‘J» (5)

 

 

C

0

2 (2)1/20

where p is the mean of the distribution of In I, or is the corresponding variance and
elf is the error function. For computational purposes, Van et al. (1977) reported that
when L = 100 cm, ,1 =4.08 and or = 0.56. This distribution was used in subsequent
computations.

The third model evaluated was the MACRO model developed by Jarvis
(1991). The ﬂuxes in the MACRO model, both within and between the ﬂow domains
and at the boundary of the proﬁle, are illustrated in Figure 2. The various equations
describing these ﬂuxes, and a full description of the MACRO model were given in
Jarvis et al. (1991).

Input requirements for the ﬁrst two models consisted of weather data only.
There were 33 inputs required for the MACRO model (Jarvis, 1991). The inputs for
the MACRO simulations were obtained in one of three ways: from direct

measurements, from general knowledge or literature sources, or through the process

97

of model calibration (Jarvis, 1991). Soil saturated hydraulic conductivity was
measured from intact soil core samples. Intact soil cores (7.6 cm diameter, 7.6 cm
height) were collected from NT, CP and RT plots on 13 October, 1993. Three cores
weretakenattheOto 10, 10to20cm, 20to40cm,40to60cm,and60to80cm.
Soil core samples were obtained with a Uhland double-cylinder, hammer-driven
sampler (Blake and Hartge, 1986). Saturated hydraulic conductivity was determined
using the constant head method (Klute and Dirksen, 1986). Cores were oven dried at
105 ' C for 48 hours and weighed for bulk density determination. Water loss between
saturation and oven dry was taken to represent total soil porosity. The average three
plots measured value was given in Table l. The value of the boundary tension was
40 cm, based on a deﬁnition of macropores as all pores larger than 75 um in diameter
(Jarvis, 1991). The other input parameter values used in the model simulation were
obtained from model sensitivity analyses conducted by Jarvis (1991).

Model performance and simulation accuracy were evaluated based on ability to
predict Br content in each layer. The four combinations of statistical criteria were
used to assess the accuracy and simulation capacity of the models (Jabro et al. , 1994).
The correlation coefﬁcient (r) is a measure of the degree of association between
simulated and measured values. The mean difference between simulated and measured
values (M.,) is a measure of the average deviation of the simulated values from the

measured values. The formula is

98

where s is the simulated value, U is the measured value, and h is the number of
observations. The positive sign of the MI represents overestimated simulation, and
the negative sign of M., suggests underestimated simulation. A t test was used to
determine whether MI was signiﬁcantly different from zero (Addiscott and Whitrnore,
1987). The degree of coincidence of the simulated and measured values was also

determined using the root mean square error (RMSE), that is

 

_ 2

RMSE=J[ M] “120- (7)
n U

where fl is the measured mean value. The lower values of RMSE suggest greater

simulation accuracy than the higher RMSE values.

RESULTS AND DISCUSSION

mm

The variation in Br concentration in soil encountered in these experiments was
large (CV > 100%) and no differences in treatments were detected in the analysis of
variance. Typically, studies on Br transport in soils report only means without
reporting variance (Butters and Jury, 1989; Dyson and White, 1987; Germann et al.,
1984; Gish et al., 1986; Hamlett et al. 1990; Zachmann et al., 1987). Because solute
concentration was affected by the spatial variation, Pol at al. (1977) suggested that

reliable estimates of their values are required. Therefore, only simple means are

99

reported in the following tables and soil proﬁle Br concentrations are presented
graphically to aid in their interpretation.
Ridge position effects on Br transport

The typical soil proﬁle distribution of Br after application and as a function of

cumulative rainfall is illustrated in Figure 3 for the ridge placement. Initially, Br

 

N
content is high near the soil surface. On 16 July, 1992, all of the applied Br :I
remained in the 60 cm soil proﬁle in the row placement treatment. The distribution 5 T
ofBr content was 82%,14%, and 4% at 0 to 20 cm, 20 to 40 cm and 40 to 60 cm ,j
depths, respectively. As rainfall increases, Br content transports from the soil surface b

to deeper in the soil proﬁle. For the 239 mm cumulative rainfall on 31 August, about
48 % of applied Br was not detected and presented below 60 cm of the proﬁle. The
recovery of the applied Br was 36%, 6% and 10% at 0 to 20 cm, 20 to 40 cm and 40
to 60 cm depths, respectively. On 29 September, when cumulative rainfall was 378

mm, 60% of applied Br was not detected and presented below 60 cm of the proﬁle.

 

Recovery of applied Br was 26%, 7%, and 7% at each depth. By 259 days after Br
application, on 16 April, 1993, when cumulative rain was 835 mm, 95% of the
applied Br was leached out of the 60 cm soil proﬁle. The recovery of Br was about 1
to 2% of applied Br at each layer.

When KBr was applied to the midrow position, Br leached much quicker than
when applied to the row (Figure 4). For the 16 July, 1992, when cumulative rainfall
since application was 66 mm, 34% of applied Br was leached out of the 60 cm depth

as compared to no Br leaching out of 60 cm under row application. Bromide contents

 

100

were similar between row placement and midrow placement at the 20 to 60 cm
depths. However, differences occurred at the surface layer. For the 239 mm
cumulative rainfall, 60% of applied Br was leached from the midrow placement below
60 cm depth compared to 48% leaching in the row placement treatment. By 378 mm
of cumulative rainfall, 70% of applied Br leached out of the 60 cm depth in the
midrow position. The faster Br leaching under midrow placement than row placement
was attributed to the midrow receiving more water than the ridge surface (Chapter 2).
During a storm event, once the soil surface was saturated, runoff can be channeled to
the midrow, as evidenced by visual ponding and increased water contents in the upper
soil proﬁle (Hamlett, 1990). Ponded soil surfaces may result in water movement
horizontally (surface runoff) or vertically (downward infiltration), or both movements
can occur simultaneously. Both types of water movement probably reduced proﬁle Br
contents. After 66 mm of cumulative rainfall, Br content differences between the row
and the midrow placement only occurred in the surface layer and may have been due
to midrow surface runoff. However, in the following rainfall events, Br content at
deeper layers was higher for the midrow placement, indieating that predominant
water movement was downward inﬁltration. After 835 mm of cumulative rainfall, by
16 April, 1993, the proﬁle Br contents were low and were similar for the row
placement and midrow placement treatments.

As indicated above, water movement from the row top to the midrow valley
was responsible for increased leaching of Br in the midrow position. However, the

lateral movement of Br applied to the row to the midrow was extremely low in 1992

 

101

(Figure 5), a dry June, but considerable in 1993 (Figure 6), a wet June. This
suggests that once Br moves into the soil, little Br moved with surface water into the
midrow, but lateral movement can be considerable when rainfall follows soon after
application. When Br was applied to the midrow, Br was transported to the ridge
position (Figure 7 and 8), with the midrow near 50 kg Br ha" in 1993 but 12 kg Br
ha“1 in 1992. The movement of Br to the row position probably relates to plant
extraction of water under the row position and subsequent transport of Br with the
redistributing water.
Chkel plow and no-tillage and row position effects on Br transport

In both the NT and CP, Br in both row positions was highest in the soil
surface and had not leached below 60 cm after 197 mm of cumulative rainfall
(Figures 9, 10 , 11, and 12). In the row, Br content increased with depth as
cumulative rainfall increased However, more Br appeared to have moved in the
midrow, and movement appeared to be greater in the CP midrow than the NT
midrow, with almost complete removal of Br from the surface of the CP and
accumulation in the Bt horizon (Figures 10 and 12). This is evidence of within
season stratiﬁeation of nutrients, such as NO,-N. Therefore, as was true in the RT
system, more leaching occurred in the midrow than row position, at least during the
growing season, as measured in 1993.

A comparison of soil proﬁle Br movement for the 0 to 80 cm depth for three
tillage and two row positions is given in Table 2. Recovery of Br was highest for RT

in the row and lowest for RT in the midrow. This reﬂects the preferential movement

102

of water through the midrow position of RT. The movement of Br was higher in CF
than NT in both positions but positions were not different in these two tillage systems.
Average across row positions, the Br recovery in CP was comparable to RT, and Br
content in the proﬁle was lower for NT. The lower recovery of Br under NT
indicates more leaching occurred under NT and this may be associated with increased
macropore continuity. As a consequence of disturbed soil surface with CP, continuity
of pores was decreased, and larger amounts of Br accumulated in the Bt horizon
under CP while Br under NT was leached to deeper zones, probably through

macropores, since little Br was measured below 40 cm in the soil matrix (Table 2).

Wat

Although Br is not a required plant nutrient, the amount taken up has been
reported to be similar to NO3-N (Owens et al. 1985). In green house and ﬁeld
experiments, Jemison and Fox (1991) found that most of the Br absorbed by the plant
was stored in the stover. In this study, Br was applied 48 days after corn planting.
Bromide treatments signiﬁcantly decreased grain yield (decreased 78 % in CP, 72% in
NT, and 78% and 68 % for row application and midrow application in RT,
respectively with LSD=5.6%) as compared with no Br treatment. Corn stover
weight was decreased 61 to 66% for Br treatments. There were no differences in
corn stover weight decreasing between tillage treatments and Br application position.
Bromide concentration in both corn grain and stover was higher for the row Br

application than midrow application in 1993. The stover Br concentration was higher

 

103

for the NT than CP (Table 3). Because high Br concentration decreased crop yield,
Brtaken up by the grain was 0.03 kg ha", for all three tillage treatments both in 1992
and 1993. Bromide taken up by stover ranged from 0.8 to 1 kg ha", which was less
than 0.3% of original Br application. These results are lower than Jabro (1994),
who reported that 6.8 to 21.2 kg Br ha" were removed by stover and less than 3% of
the applied Br was removed in the harvested grain when Br applied at the time of

corn planting.

II I l I! l' l .
The statistieal comparisons of ﬁeld measured and model simulated values of Br
content in the O to 60 cm soil proﬁle are given in Table 4. The modiﬁed Burns
equation (Equation 2) most successfully predicted Br content in the row application
with row sampling (RR) and midrow application with midrow sampling (VV) in 1992
and R in 1993. The M,I were not signiﬁcantly different from zero, the RMSE were
smaller and r were higher than other models. The modiﬁed Burns equation
underestimated values in the 0 to 20 cm depth for R in 1992 and 1993 (Table 5).
For the 20 to 40 cm and 40 to 60 cm depths, the equation underestimated at the early
sampling dates and overestimated at later sampling dates for both 1992 and 1993
(Table 6). For the W in 1992, the equation overestimated for all three depths and
for the entire season in 1992. Although the r value was high for the W in 1993,
signiﬁcant M, and high t value between predicted and measured values indicated that

the equation failed to predict W in 1993 (Tables 4 and 6). The modiﬁed Burns

104

equation did not predict the CP and NT for both the row and midrow position
samplings, as indicated by lower r value, signiﬁcant t and larger RMSEs (Tables 4
and 7).

The Transfer Function Equation (TFE) performed reasonably well and gave
satisfactory predictions of measured Br content for R and W in 1992, and R in
1993. Satisfactory predictions were indicated by reasonable M,’s, non-signiﬁcant t
values, and high r values (Table 4). For R in 1992, the model overpredicted at
early sampling dates and underpredicted at later sampling dates at 0 to 20 cm depth,
and underpredicted at early dates and overpredicted at later dates in the 0.2 to 0.6-m
depths. For W in 1992, the model overpredicted for the entire season at all depths
(Tables 4 and 5). Overpredicted values were found at later times in deeper layers for
R in 1993. Similar to the Burns equation, the correlation coefﬁcient was high for
W in 1993, but signiﬁcant differences between measured and predicted value
indicated that TFE did not successfully predict W in 1993 (Tables 4 and 6). In
contrast, the low r values, signiﬁcant Md’s, and larger values of RSME indicated that
TFE did not perform well for CP and NT for both row and midrow sampling (Tables
4 and 7).

In 1992, the agreement between measured and MACRO simulation was
acceptable for R and W, and the model met the statistical criteria, as indicated by a
M., that was not signiﬁcantly different from zero, a small RMSE, and a high r. The
overpredicted values were found at 20 to 60 cm depths between 238 and 378 mm

cumulative rainfall. The model over-predicted W at early dates at the surface and

105

later dates at deeper depths (Tables 4 and 5). In 1993, the model prediction was
acceptable for R with a reasonable r and a low M, value (Table 4). The
underpredicted values occurred at early sampling times and at three depths. In
contrast, the MACRO predictions in 1993 failed to meet the statistical evaluation
criteria for W (Tables 4 and 6) in RT and all positions in CP and NT (Tables 4 and
7). h]
None of the models predicted the Br contents under NT and CP in 1993. All ‘

models predicted the Br contents in the RT system with the exception of the Br

 

applied and sampled in the midrow of the ridge (VV). The modiﬁed Burns equation, U
the simplest model tested, was most successful in predicting Br contents of the models

tested.

SUMMARY AND CONCLUSION

 

Bromide movement were evaluated in three conservation tillage systems and
two row positions. Burns leaching equation, the TFE of solute transport, and the
MACRO model were tested using ﬁeld data under natural, non-steady state rainfall
conditions.

This study suggested that RT with Br placement in the row results in less Br
leaching than NT and CP. In contrast, Br placement in the midrow increased Br
leaching. Average across row positions Br leaching rate under RT was compatible
with CP. Low proﬁle Br content for NT indicated that chemical leaching potential

was higher for NT than for CP and RT. The higher leaching rate for NT was

 

106

attributed to undisturbed soil surfaces with macropores ﬂow. Stratiﬁcation of Br
occurred in Bt horizon in CP during growing season. This study also revealed that
rates of chemical movement from midrow to row were higher than rates of chemical
movement from the row to midrow under RT.

Model testing in this study demonstrated that the modiﬁed Burns equation,
TFE and MACRO model successfully predicted Br movement for RR. None of the
models predicted the Br contents under NT and CP. The Burns equation had the best
accuracy of prediction, and the accuracy of the model prediction by TFE was better
than MACRO. The input parameters of the MACRO model can be altered for
variable ﬁeld conditions. This suggests that MACRO may have the potential to
predict chemical leaching under different tillage. It also appears that both the TFE
and MACRO models overpredicted Br content for W for the entire season and for all
layers. To simulate chemical movement in the midrow under RT, the preceding
models need to be modiﬁed, and input parameters need to be readjusted. The slope
of the land, which causes to overestimation or under estimation of Br content due to

surface water runoff, needs to be included in input parameters.

The MACRO model was supplied by Dr. N. Jarvis (Department of Soil

Sciences, Swedish University of Agricultural Sciences, Uppsala, Sweden).

LIST OF WCES

Addiscott, T.M. and R.J. Wagenet. 1985. Concepts of solute leaching in
soils: a review of modeling approaches. J. Soil. Sci. 36:411-424.

Addiscott, T.M., and A.P. Whitmore. 1987. Computer simulation of changes
in soil mineral nitrogen and crop nitrogen during autumn, winter and
spring. J. Agric Sci. Camb. 109:141-157.

Al-Darby, A.M. and B. Lowery. 1987. Seed zone soil temperature and early
corn growth with three conservation tillage systems. Soil Sci. Soc. Am
J. 51:768-774.

Blake, G.R., and Hartge K.K. Hartge. 1986. Bulk density. In A. Klute (ed.)
Method of soil analysis, part 1. 2nd. Agronomy 9:363-375.

Burns, LG. 1975. An equation to predict the leaching of surface-applied
nitrate. J. Agric. Sci., Camb. 85:443-454.

Butters, G.L. and W.A. Jury. 1989. Filed scale transport of bromide in an
unsaturated soil 2. Dispersion modeling. Water Resour. Res. 25: 1583-
1589.

Dyson, J .S. and R.E. White. 1987. A Comparison of the convection-
dispersion equation and transfer function model for predicting chloride
leaching through an undisturbed, structured clay soil. J. Soil Sci.

38: 157-172.

Eckert, DJ. 1987. Evaluation of ridge planting systems on a poorly drained
lake plain soil. J. Soil Water Conserv. 42:208-211.

Germann, P.F., W.M. Edwards, and LB. Owens. 1984. Proﬁle of bromide
and increased soil moisture after inﬁltration into soil with macropores.
Soil Sci. Soc. Am. J. 48:237-244.

Gish, T.J., W. Zhuang, C.S. Helling, and P.C. Kearney. 1986. Chemical
transport under no-till ﬁeld conditions. Geodema. 38:251-259.

Hamlett, J.M., J .L. Baker, and R. Horton. 1990. Water and anion movement
under ridge tillage: a ﬁeld study. Trans. ASAE. 33:1859-1866.

107

108

Jabro, J.D., J.M. Jemoson, JR, Richard H. Fox, and DD. Fritton. 1994.
predicting bromide leaching under ﬁeld conditions using SLIM and
MACRO. Soil Sci. 157:215-223.

Jarvis, N .J . 1991. MACRO - A model of water movement and solute
transport in macroporous soils. Report and dissertations #9.
Department of Soil Sciences, Swedish University of Agricultural
Sciences. Uppsala, Sweden.

Jarvis, N.J., L. Bergstrom, and RE. Dik. 1991. Modeling water and solute
transport in macro-porous soil. II Chloride breakthrough under non-
steady ﬂow. J. Soil Sci. 42:71-81.

Jerrrison, J.M., Jr., and R.H. Fox. 1991. Corn uptake of bromide under
greenhouse and ﬁeld conditions. Commun. Soil Sci. Plant Anal.
22:283-297.

Jury, William A. 1982. Simulation of solute transport using a transfer
function model. Water Resour. Res. 18:363-367.

Jury, William A., Lewis H. Stolzy and Peter Shouse. 1982. A ﬁeld test of the
transfer function model for predicting solute transport. Water Resour.
Res. 18:369-375.

Klute , A. and C. Dirksen. 1986. Hydraulic and diffusivity: Laboratory
methods. In A. Klute (ed.) Methods of soil analysis, Part 1. n ed.
Agronomy. 9:687-734.

Owens, L.B., R.W. Van Keuren and W.M. Edwards. 1985. Groundwater
quality changes resulting from a surface bromide application to a
pasture. J. Environ. Qual. 14:543-548.

Pol, R.M. Van De, P.J. Wierenga, and D.R. Nielsen. 1977. Solute
movement in a ﬁeld soil. Soil Sci. Sco. Am. J. 41:10—13.

Potter, K.N., R.M. Cruse, and R. Horton. 1985. Tillage effects on soil
thermal properties. Soil Sci. Soc. Am. J. 49:968-973.

SAS Institute. 1990. SAS/STAT user’s guide. Version 6. SAS inst., Cary, NC.

Scotter, D.R., R.E. White and IS. Dyson. 1993. The Burns leaching
equation. J. Soil Sci. 44:25-33.

Smith, 8.1., and R.J. Davis. 1974. Relative movement of bromide and

109

nitrate through soils. J. Environ. Qual. 3:152-155.

Towner, GD. 1983. A theoretical examination of Burns’ (1975) equation for
predicting the leaching of nitrate fertilizer applied to a soil surface. J.
Agric. Sci., Camb. 100:293-298.

Van, de Pol, R.M. , P.J. Wierenga, and D.R. Nielsen. 1977. Solute
movement in a ﬁeld soil. Soil Sci. Sco. Am. J. 41:10-13.

Zachmann, J.E., D.R. Linden, and C.B. Clapp. 1987. Macroporous
inﬁltration and redistribution as affected by earthward, tillage, and
residue. Soil Sci. Soc. Am. J. 51:1580-1586.

 

110

Table 1. Field measured soil physical properties used an input value for

 

 

MACRO model

Depth BD Total Porosity Sat. 0 K.,
(cm) (s cm”) (96) (95) (cm hr‘)
010 1.46 45.1 41.2 13
1020 1.68 36.4 35.1 2
2040 1.72 34.3 33.5 1
40-60 1.68 37.7 35.4 11
6080 1.67 36.7 34.7 15

 

BD=Bu1k density
K..=Saturated hydraulic conductivity
Sat. 0 = Saturated volummetric soil water content

111

Table 2. Comparison of Br recovery for the 0 to 80 cm depth under three
tillage treatments and two position after 288 mm cumulative rainfall

in 1993.

 

Depth Chisel Plow No-tillage

(cm)

 

 

Ridge Till

 

 

 

 

row midrow row midrow row midrow
kg Br ha'1
0-20 43.9 13.2 35.7 32.2 70.2 9.1
20-40 58.2 109.7 29.8 61.0 96.1 16.1
40-60 19.2 8.8 11.6 4.6 64.1 16.0
60-80 20.4 2.3 5.4 2.0 21.6 7.5
Total 98.2 134.0 82.5 99.8 252.0 48.7

 

112

Table 3. Corn plant tissue Br concentration under three tillage treatments

 

 

 

 

 

 

in 1992 and 1993.
1992 1993
Br1 mg kg“
Tillage applied position Grain Stoves Grain Stoves
Ridge till row 10 341 22 145
Ridge till midrow 10 310 17 93
Chisel plow row & midrow 13 311

No-tillage row & midrow 13 436

 

113

Table 4. Comparison of ﬁeld measured and simulated values of Brl contents in 60 cm
soil proﬁle of Kalamazoo loam soil.

 

 

 

 

 

 

Year 1992 1993

Tillage Ridge rill M Mags.
Br-

applied position row midrow row midrow row W
sampling position row midrow row midrow row midrow row midrow
M, T -0.95 14.85 -l6.66 37.34 15.07 7.27 12.77 19.98
r II: 0.94 0.91 0.93 0.95 0.26 0.14 0.77 0.28
t § —0.14 1.52 -1.91 2.53* 2.73“ 0.70 4.14“ 3.49"'
RMSE 1 45.2 93.2 35.6 179.9 75.8 107.5 38.7 98.7
I t] E . E .

M, 14.49 30.29 10.37 64.37 42.96 35.16 40.66 47.87
r 0.82 0.77 0.80 0.85 0.33 0.56 0.50 0.45
t 0.92 1.65 0.68 2.44* 2.91“ 2.77* 2.99“ 3.14*
RMSE 102.9 174.9 61.9 321.6 202.7 131.8 170.6 262.8
W21

M, 11.65 27.45 -4.56 49.44 27.67 19.87 25.37 32.58
r 0.77 0.81 0.67 0.81 0.24 0.41 0.62 0.30
t 0.78 1.58 -0.28 2.43* 3.43* 2.08 4.26* 3.75*
RMSE 97.5 165.1 66.3 248.6 110.6 99.3 74.6 149.7

 

1' mean difference between simulated and measured values

1 correlation coefﬁcient
§ t tCSt
1 root mean square error

114

Table 5. Comparison of predicted and measured Br contents for three simulation
models for ridge till in 1992.

 

111121" E'llll
Depth Cumu. Rain Burns TFE MACRO row midrow

 

 

 

(cm) (mm) kg Br ha’l

0-20 66 234. 1 276.5 262.0 245.9 132. 8
0-20 239 58.6 60.0 86.3 111.7 79.1
0-20 378 40.2 13.5 1.3 79.7 35.7
0-20 835 18.1 1.7 0.0 2.1 2.9
20-40 66 51.4 22.4 47.0 53.0 55.1
20-40 239 47.2 132.0 135.6 17.3 32.6
20-40 378 34.8 87.3 33.9 22.1 28.8
20-40 835 17.0 8.2 0.0 2.5 2.5
40-60 66 11.3 ' 0.2 4.3 15.5 12.6
40-60 239 37.9 69.0 83.6 31.3 13.2
40-60 378 30.1 82.2 91.9 22.0 18.5

40-60 835 16.0 29.1 2.0 4.8 4.7

 

115

Table 6. Comparison of predicted and measured Br contents for three simulation
models for ridge till in 1993.

 

llllE ... E'llll

 

 

 

Depth Cumu. Rain Burns TFE MACRO row midrow
(cm) (mm) kg Br ha‘1

020 30 243.3 299.3 249.9 280.7 120.3
020 130 95.8 175.2 99.3 106.3 47.9
0-20 218 61.5 85.8 9.9 83.8 14.1
0-20 288 47.8 34.5 1.0 70.2 9.1
20—40 30 46.0 0.6 56.9 89.1 29.3
20-40 130 65.2 100.8 126.1 65.3 18.0
20-40 218 48.9 127.2 93.8 26.9 23.3
20-40 288 40.2 123.0 26.9 96.1 16.7
40-60 30 8.7 0.2 7.3 39.3 17.0
40-60 130 44.4 18.9 63.3 37.6 3.3
40—60 218 38.9 56.4 101.9 14.8 11.2
40-60 288 33.8 77.0 83.5 64.3 16.1

 

116

Table 7. Comparison of predicted and measured Br contents for three simulation
models for no-tillage and chisel plow in 1993.

 

”1121.. EH“

 

 

 

Depth Cumu. Rain Burns TFE MACRO M M
row midrow row midrow
(cm) (mm) kg Br ha"
0—20 70 67.2 77.6 94.4 57.7 31.1 38.2 60.8
0-20 91 47.1 28.8 35.7 35.7 32.1 43.8 12.5
0-20 115 40.2 15.0 25.7 31.7 12.4 18.5 8.3
20-40 70 52.2 150.4 77.6 50.5 12.9 7.7 12.2
20-40 91 39.7 121.3 62.7 29.8 61.6 58.8 110.9
20-40 115 34.8 102.0 50.4 27.7 24.6 34.7 61.0
40-60 70 40.5 48.0 52.0 8.9 1.9 5.3 7.4
40-60 91 33.5 78.0 54.5 11.5 4.2 18.9 8.1
40—60 115 30.1 82.2 48.9 32.7 31.9 37.6 70.0
60-80 70 31.4 16.5 32.9 4.0 1.7 0.0 2.1
60-80 91 28.2 39.0 44.2 5.4 1.9 6.17 2.29
60-80 115 26.1 46.8 42.9 22.1 14.8 20.4 28.1

 

117

 

Br- application area

RR Row application and row sampling
RV Row application and midrow sampling
VR midrow application and midrow sampling
VV midrow application and midrow sampling

Figure 1. Illustration of Br application in the row and midrow position for ridge till.

118

 

 

 

Runoff . . .
Precipitation
water uptake
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Figure 2. Illustration of precesses and ﬂuxes in MACRO model
(redraw from Jarvis, 1991).

119

Row application, row sampling 1992

 

 

 

 

 

Figure 3. Br concentration changes with cumulative rainfall and depths for the row
Br application and row sampling in ridge tillage in 1992.

120

Midrow application, midrow sampling in 1992

 

 

 

 

 

 

Figure 4. Br concentration changes with cumulative rainfall and depths for the
midrow Br application and midrow sampling in ridge tillage in 1992.

121

Row application, midrow sampling 1992

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

Figure 5. Br concentration changes with cumulative rainfall and depths for the row
Br application and midrow sampling in ridge tillage in 1992

122

Row application, midrow sampling 1993

 

 

 

 

Figure 6. Br concentration changes with cumulative rainfall and depths for the row
Br application and midrow sampling in ridge tillage in 1993.

123

Midrow application, row sampling 1992

 

 

 

 

Br (kg ha")

 

Figure 7. Br concentration changes with cumulative rainfall and depths for the
midrow Br application and row sampling in ridge tillage in 1992.

124

Midrow application, row sampling 1993

 

 

Br (kg ha")

 

Figure 8. Br concentration changes with cumulative rainfall and depths for the
midrow Br application and row sampling in ridge tillage in 1993.

125

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128
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Figure 12. Br concentration changes with cumulative rainfall and depths for the
midrow sampling in chisel plow in 1993.

SUMMARY AND CONCLUSION

This study examined the inﬂuences of conservation tillage systems, the
residual beneﬁts of long-term animal manure applications, and chemical inputs on
corn and soybean production, on soil physical properties and on the fate of N. A Br
tracer was used to evaluate the potential for NO3-N leaching in the three tillage
systems. The Burns leaching equation, transfer function equation, and the MACRO
model were tested using ﬁeld data under natural, non-steady state rainfall conditions.

Manure application history and chemical inputs interacted in their effects on
corn production. Manure history increased corn grain yield in LI only. Without N
fertilizer, corn under NT and RT were generally more deﬁcient in N and yields were
less than under CP. High chemical input increased corn grain yield, N concentrations
in corn tissue and N uptake. The differences in NI uptake between HI and LI were
tempered by manure applications and affected by tillage. Manure application history
with chisel plowing tended to increase N uptake in corn.

Manure application history increased weed populations, causing lower soybean
plant populations and ultimately decreasing soybean yields. Both NT and RT are
preferable tillage methods for soybean production in the Kalamazoo loam soil of

Michigan, since crusting was a serious limitation in CP.

129

- In lin-

 

13 0

Ridge till increased air-ﬁlled porosity. Bulk density was lower and total
porosity was higher in ridge till after harvest, but there were no differences in tillage
treatments before planting. Manure applications decreased bulk density and increased
total porosity, macroporosity and air-ﬁlled porosity. The effect of manure application
history was to increase residual proﬁle NO,-N, soil solution NO,-N, and N, and
thereby increase the potential for NO,-N leaching. Nitrogen fertilizer was the major
source contributing to N O,-N leaching, especially in low yielding years when crops
could not utilize additional N. Baseline levels of N O3-N at the base of the soil
proﬁle, represented by levels under LI, were consistently below 15 mg N L" and
were elevated to > 25 mg N L" soon after N fertilization. The CP had consistently
higher soil proﬁle N03-N than NT and RT in spring and fall. This suggests that the
disturbed soil surface under CP enhanced mineralization in early spring. The higher
NO,-N for CP in fall contributed higher N, over winter. Ridge till had consistently
lower proﬁle NO,-N but high soil solution NO,-N, indicating RT had the highest
potential for NO,-N leaching during the growing season. Ridge till had consistently
lower 0 in the row than other tillage systems, indicating water moved to the valley of
the nridrow. The preferential movement of water in the midrow may explain the
lower 0 and higher NO,-N in solution. There was little evidence of proﬁle
stratiﬁcation of N O,-N at horizon boundaries. This was in part related to the
sampling times occurring before N applieation and after harvest.

Ridge till with Br placement in the row resulted in less Br leaching than NT

and CP. In contrast, Br placement in the midrow for RT leached more Br than CP

131

and NT. Averaged across row positions, Br leaching rates were higher for NT than
CP and RT, and RT was comparable to CP. This indicated that chemical leaching
potential was higher for NT than for CP and RT. The higher leaching rate for NT
was attributed to undisturbed soil surfaces with macroporou ﬂow. Stratiﬁcation of Br
occurred in the Bt horizon in CP treatments during growing season. The rates of
chemical movement from the midrow to row zone were higher than rates of chemical
movement from the row to midrow zone under RT. Model evaluations demonstrated
that the modiﬁed Burns equation, TFE and MACRO model successfully predicted Br
movement for RT. None of the models predicted the Br contents under NT and CP.
Conclusions of this study include:

1. The residual effects of manure history were evident in increased N
mineralization 5 years after manure application ceased. As a result of higher NO3-N
concentration in the soil proﬁle and soil solution, manure history increased N leaching
potential.

2. Chemical inputs increased corn grain yield and N uptake consistently. It
was apparent that NO,-N leached out of the root zone soon after N fertilization. To
reduce N O3-N leaching potential, the time and amount of N application needs to be
managed properly.

3. Nitrate leaching potential was higher in NT and RT than CP during growing
season. N03-N leaching for NT was attributed to macropores ﬂow. The midrow
zone of the RT contributed greater chemical leaching due to surface water

redistribution, resulting from the surface conﬁguration.

13 2
4. The CP, as a disturbed surface system, enhanced soil N mineralization,

accumulated chemicals in the Bt and maintained residual NO3-N higher in the soil
proﬁle NO3-N after the growing season. Leaching potential was higher for CP during

the winter season.

nrcurcnn STATE UNIV. LIBRARIES
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