NET RETURNS OF VARLABLE CORN AND SOYBEAN CROPPING...
NET RETURNS OF VARLABLE CORN AND SOYBEAN CROPPING SYSTEMS
A THESIS
SUBMITIED TO THE GRATUATE SCHOOL
OF THE UNIVERSI’IY OF MINNESOTA
Marnadou Ndiaye
IN PARTIAL FULFILLMENT OF THE REQUIREMENTS FOR THE DEGREE
o f
MASTER OF SCIENCE
May, 1990
A C K N O W L E D G E M E N T S
Most gracious thanks to Dr. Robert Kent Crookston for his guidance as an advisor,
his encouragement troughout the study and the course program, and his tremendous help
in the writing of this thesis. Thanks to Jim Kurle who taught me how to use and to t-un
computer programs for the a.nIysis of the experiment. Thanks are extended to fellow
menbers of the Crop Production Project. Sincere thanks to Drs. R. Stucker and. V. B.
Cardwell for their assistance, suggestions, and comments on the proposa1 and the analysis
of the thesis. Cordial gratitude to the Department of Agronomy and Plant Genetics staff
and the State. of Minnesota for providing facilities and resources for the research. Thanks
to Drs. Pierre Robert, Jeffrey Apland, and Dale Hicks for reviewing the thesi:s, offering
constructive comments, and serving on the examining committee. Sincere appreciation and
thanks are addressed to all friends in the IJ.S.A. for their encouragement and. support.
Gratitude goes to my lovely sisters and Senegalese friends for their invaluable help
throughout my stay in the U.S.,A. Gratitude goes to the “Institut Senegalais de
Recherches Agricoles” and to The Govemment of Senegal.
ii
FOEWARD
This thesis is written as an manuscript to be submitted to the Journal of&duction
&riculture. It is followed by appendixes containing information about soi1 and plant
nutrients not directly referred to in the manuscript.
. . .
111
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F O R E W A R D
This thesis is written as an manuscript to be submitM to the Journal oL&oduction
Aticulture. It is followed by appendixes containing information about soi1 and plant
nutrients not directly referred to in the manuscript.
iv
1
TBLE OF CONTENTS
Page
Abstract
2
Literature review-Objectives
3
Mater&& and Methods
5
Results and Discussion
7
Conclusion
1 1
References
12
Tables
14
Appendix 1
2 3
Appendix 2
24
Appendix 3
2 5
Appendix 3.1
2 6
Appendix 3.2
2 7
Appendix 3.3
2 8
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2
AE3STRAcT
Com and soybean grown in sequence is one of the most popular cropping systems
in the United States; the com-soybean rotation has enormous importance economically. O
The “rotation effect” is known to increase yields of both crops, but little is known
about the economic consequences of various corn -soybean rotational patterns compared
with monoculture. This study was undertaken to determine the most profitable
com-soybean cropping pattern for Minnesota, based on both actual and sensitivlty price
analyses. Rotations investigated were: corn monoculture, soybean monoculture, corn
grown after two years of soybean, soybean grown after two years of com, a.nd an annual
alternation of the two crops. The field study was conducted at three locations: Lamberton,
Rosemount and Waseca, MN. Lamberton and Waseca are positioned within the “com
belt,” whereas Rosemount is positioned beyond the northerly fiinge. Actual analysis
(1984-1989) indicated that com following two years of soybean was the most profitable
cropping system at both com-belt locations. At Rosemount there was no cle.ar net-return
pattem. Averaged over all locations, com following two years of soybean was definitely
,the most profitable cropping system however. Soybean monoculture provide:d the lowest
,average retum, and com monoculture had the lowest returmoperating cost ra.tio at a11
locations. Projection analysis indicated that com after two years of soybean would be the
most profitable com-soybean rotation in the Minnesota com belt under ail expected com or
soybean price combinations. Com monoculture was projected to be the least profitable
pattem, and soybean monoculture the second least profitable pattem. Rrices did not
include govemment supports.
__,,._.
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3
LITERATURE REVIEW - OBJECTIVES
In the United States, the annual rotation (alternation) of corn and soybe’an is a very
c:ommon cropping system (Sundquist et al., 1982). Both com and soybean yield better
when grown on land previously sown to the other trop than when grown continuously
(Higgs et al., 1976; Slife, 1976; Peterson and Varvel, 1989a and 1989b). In l.ong term
s.tudies conducted at Waseca and Lamberton, Crookston et al. (1990) found th.at compared
with monoculture, either com or soybean yielded an average of 8% better when altemated
and about 16% better when kept out of monoculture for at least two years.
Early in the 20th Century, Amy (19 17) reported a higher net income per acre from
com grown after legumes than grown continuously. Later, Curtiss (1926) demonstrated
that a rotation of four or five years was of more value than a shorter three-year rotation
which was defiiitely preferable to a two-year system or to continuous cropping. Recently,
the beneficial effect of rotation versus continuous monoculture of com and soybean has
been estimated in the U.S. to be worth at least 300 million dollars annually (Sundquist et
aI., 1982). Crookston (1984) has shown that Minnesota. farmers cari raise th.eir net profit
on com and soybean by as much as 50% tiom properly exploiting the rotation effect.
Daniel and Mueller (1986) found that com-soybean rotation increased the net profit in the
com year and in the soybean year by $36.00 and $20.00 per acre, respectively. In
contrast, Voss and Shrader (1979) reported that continuous com was among the most
profitable systems, depending on the economic values assigned to the crops. Lazarus et
al.( 1980) found greater annual returns from continuous com than from a rotational
com-soybean system .
Conflicting results about the economics of com-soybean rotation systems justified a
closer look at the rotation effect, particularly in terrns of net return to the farmer. The first
objective of this study was to compare the profitability of fîve diiferent com-soybean
. . ..- a.*lmlll
-. -. -
,__-__
--._.^ -.-<.-. “. _I--~*IsIQII*vI.mB e-
cropping sequences over the six-year period 1984-1989 in Minnesota. The second
objective was to predict the most profitable htinesota corn-soybean cropping pattern for
the forseeable future via simulated scenarios based on expected fluctations in commodity
prices.
MATERLALS ANDMETHODS
A six-year trop rotation study was established in 1.984 at the Southwest Experiment
Station at Lamberton, at the Rosemount Experiment Station, and at the Southelm
E,xperiment Station at Waseca, Minnesota. The soils at these locations are : Wlebster clay
loam, Waukegan silt loam, and Nicollet clay loam, respectively. The corn hybrid was
‘Pioneer Brand 3780’ and the soybean variety was ‘Hodgson 78’.
Each experimental area was chisel plowed each fall. Fertilizer N (urea or ammonium
nitrate), P (superphosphate), and K (potash) were applied according to University of
h4innesota soi1 test recornrnendations for maximum production of each trop. Herbicides:
alachlor (lasso), linuron (lorox), and bentazon (basagran); and insecticides: carbofuran
(furadan), terbutos (counter), and chlorpyrifos (lorsban) were applied when necessary for
weed and insect control.(appendix 1).
Five different corn and/or soybean cropping sequences (Table 1) were ‘arranged in a
randomized complete block design replicated four times. Each plot consisted of eight rows
30 feet long spaced 30 inches apart. There were four replications at each location each
year. Grain yield was obtained by harvesting the two tenter rows from each plot. Yield
values were corrected for moisture (reported at 15.5%, and 13.5% moisture for corn and
soybean, respectively).
Investigating the economic implications of any agricultural practice requires research
on the individual components of a farm, the whole farm, commodity markets, national and
international agricultural economies,etc. (Madden and Dobbs, 1988). In accessing
incentives to adopt trop rotation sequences, various factors must be accountered. for.
Complete enterprise budgets may include all fixed and variable cost and returns associated
with the farm. According to Boehlje and Eidman (1984 ) “The distinction between fixed
and variable costs is imporatnt in decision -making. Only variable costs should be
6
considered by the manager in deciding what to produce, how to produce and ‘how much to
produce in the short run. Fixed costs Will remain at the same level regardless of these
Idecisions. Thus, neither fïxed cash nor non cash costs should be considered in
decision-making”.
Our approach was to deal with the operating costs and net returns
associated with production activities of a typical Minnesota farrn. We assumed that trop
sequence was the only aspect of the farm that varied. Such an economic approach may
suffïce for decision-making in the area of adopting more valuable trop sequences.
Operating costs specifïcally associated with either corn or soybean, and incurred for the
production of that trop were considered. According to our particular situation, adjustmenrs
were made by accurately determining the cost of fertiliser, seed, herbicide, and insecticide
(table 2). Other operating costs were taken from “What to grow in 1989” (FUer et al.,
1989) (table 3). Ail operating costs were based on 1989 prices. Revenue per acre was
calculated on the basis of the yield of com and / or soybean multiplied by the product price.
Operating costs were charged against revenues to obtain per acre net returns. Statistical
analysis was via the General Linear Procedure of Statistical Analysis System (SAS, 1985),
A variety of possible net return scenarios were also calculated for a range of com
and soybean price combinations. Price combinations were based on com and soybean
prices for the 15-year period 1975 to 1989; costs and expenses were maintained at 1989
levels.
7
RESULTS AND DISCUSSION
Economie analvsis based on 1989 dollar value
The annual grain yield of the fïve cropping systems are given in table ,4. Enterprise
budgets for the six year period 1984- 1989 were based on actual yields of com. and soybean
grain for each year, and on the 1989 prices for com and soybean of $2.40 and $5.85 per
bushel, respectively. Operating costs were also fixed at 1989 values.
Over the six years, retums at Lamberton ranged from $140 per acre per year for
continuous soybean to $188 per ac,re per year for com grown after two successive years of
soybean (Table 5). Com following two years of soybean provided a significantly greater
retum than any other cropping system. Retums obtained from com monoculture,
altemated com and soybean, and soybean grown after two years of com were not
significantly different. Soybean monoculture provided the lowest retum.
Waseca results were similar to those obtained at Lamberton. Retums varied from
$9 1 per acre per year for soybean grown after two years of com, to $155 per acre per year
for com grown after two years of soybean. Com after two years of soybean provided a
signiflcantly g-mater retum than any other cropping system. There were no sign:ifkant
differences among the remaining cropping pattems.
At Rosemount, retums ranged from $118 per acre per year for continuous soybean
to $147 per acre per year for the altemate com-soybean system (Table 5). Continuous corn
and an annual rotation of com and soybean provided nearly equally high retums;
continuous soybean provided the lowest retum. Over all locations, retums ranged from
$119 per acre per year for continous soybean to $160 per acre per year for com following
two years of soybean (Table 5). Com after two years of soybean retumed $33 per acre per
year more than the average of all other sequences. Continuous soybean was the least
profitable system and retumed $24 per acre per year less than the average of a11 other
sequences. The difference between the most profitable system (SSCSSC) and the least
8
profitable system (SSSSSS) was $46 per acre.
The fact that results from Rosemount were SO different from the other two locations
is worthy of some discussion. Rosemount is located north of the other two sites, and has
a strikingly different soi1 type (appendix 2). Soils at the three locations are classified as
follows: Lamberton, Webster clay loam (fine, loamy, mixed, mesic Typic Haplaquoll),
Waseca, Nicollet clay loam (fine, loamy, mixed, mesic Aquic Hapludoll) ; Rosemount,
Waukegan silt loam (fine, silty over sandy, skeletal, mixed, mesic Typic Hapludolls) ).
Soi1 depth at both Lamberton and Waseca is greater than 6 feet, whereas soi1 depth at
Rosemount is about 20 inches below. Lamberton and Waseca are located well within the
“com-belt” region of Minnesota, whereas Rosemount lies beyond the northem fringe. The
Lamberton and Waseca results thus represent. typical com-belt soi1 and climatic conditions,
whereas the Rosemount results better represent more marginal conditions.
Corn after two successive years of soybean was the most profitable cropping
sequence at both Lamberton and Waseca. Hesterman et al. (1987) demonstmted higher
gross margins for com and soybean in rotation than for continuous com at these same
locations. Results obtained by some authors have shown that gross retums were
significantly influenced by rotation in comparison with monoculture (Zetner and Campbell.
1988; Jansen et al.,1987). Our results contradict those of Lazarus et al. (1980) who
concluded that monoculture of com was more profitable than rotation.
TO estimate the relative efficiency of each cropping sequence, we calculated
retumloperating- cost ratios (Table 6). A low value for this ratio represents a situaton
which could contribute to cash flow problems for some farmers. At Rosemount, for
example, retums from continuous com, alternate com-soybean, and com after two years
of soybean were quite low. Continuous com had the lowest return/operating cost ratio for
all locations (Table 6). If credit is limited, farmers would certaintly consider crops with
highest ne.t retum-operating cost ratios, which give enough net retum to caver operating
costs incurred.
9
Sensitivitv analvsis based uoon combinations of com and sovbean priceg
The average retums in Table 5 were based on actual yields, prices and costs during
the period 1984-1989. While these retums may be of interest from a historical standpoint,
they are of limited value in projecting future retums even from these same cropping
sequences in these same locations. In order to obtain some estimate of expected retums
from com and soybean grown in various sequence combinations on these sites in the
future, we developed several expected-retum scenarios based on projected yields and
prices at these sites. Yields for the scenarios were the yields from this six-year
(1984-1989) study. Costs were 1989 costs. Prices were derived from average com and
soybean prices in Minnesota over the 15year period 1975 1989 (Table 7).
From Table 7, we chose the lowest (1986) price of $1.46 per bushel, the highest
(1983) price of $3.05 per bushel, and a somewhat medium (1989) price of $2.40 per
bushel for com. We then used the 15-year average soybeamcom ratio of 2.7 for a medium
ratio. High (3.2) and low (2.2) ratios were determined by adding and subtracting the
YS-year ratio standard deviation. This provided nine com-soybean price combinations
which we considered to reflect prices likely to be encountered in the future.
With a low com price, com following two years of soybean provided the
consistently highest projected retums at both Lamberton and Waseca regardless of the
soybean:com price ratio (table 8). Continuous soybean also provided a high. retum when
the soybean:com price ratio was 3.2. At Rosemount there was no clear net retum pattem,
except that continuous com provided the lowest retum under all soybean:com price ratios.
With a medium com price, com following two years of soybean again provided the
consistently highest projected retum at both Lamberton and Waseca. At Rosemount, there
was once again no clear trend (table 8).
With a high com price, highest retums again carne from the SSCSSC cropping
sequence at both of the com-belt (Lamberton and Waseca) sites, regardless of the
10
s~ybean:com price ratio (table 8). At Rosemount, there was no clear pattern.
In order to better visualize the projected performance of the five sequences, the
results of each com price and soybeamcom price ratio combination were portrayed by rank
(Table 9). The superiority of the SSC pattem at the Lamberton and Waseca locations is
clear. It cari also be seen that continuous com achieved tbe number 5 ranking more than
any other sequence at these two locations. With only two exceptions, whenever
continuous com was not ranked 5th, continuous soybean fïlled the number 5 rank. In the
two exceptional situations, the 5th ranked sequence was CCS. Thus it is clear that
monoculture of either trop, but especially of com, is likely to result in lowest retums for
farmers in the Minnesota com belt unless future prices fluctuate considerably from the
1975- 1989 pattem.
At Rosemount, there was no clear ranking trend. CSCSCS was projected to be
more profitable four times, SSSSSS three times, and CCCCCC two times. The CCSCCS
and SSCSSC sequences were never projected to be most profitable.
11
C O N C L U S I O N
This study was conducted under the condition of trop selection being limited to com
and soybean, with resulting cropping systems being some sequential combinations of these
two crops. We conclude that choice of com soybean cropping sequence cari be of
considerable economic importance for Minnesota farmers. The sequence of
soybean-soybean-com (S S C) clearly was (and is projected to be) the most profitable
sequence across a11 locations, but especially at the two com-belt locations. However, not
all farmers in the state cari adopt such a system, other factors, particularly government
prices Will influence trop selection.
1 2
REFERENCES
1.
Amy, A. C. 1917. Crop rotation investigation field experiments. University of
Minnesota Ag. Exp. Stn., Bull. 170.
3
Ad. Boehlje,M.D.,and V.R.Eidman. 1984. Farm management. Ed. John Willey &
Sons New York. Chichester. Brisbane. Toronto. Singapore.
3.
Crookston, R. K. 1984. The rotation effect: what causes it to boost yields? Crops
and Soils Magazine. 36(6)12- 14. Am. Soc. Agron., Madison, WI.
4.
Crookston, R. K., J. E. Kurle, P. J. Copeland, J. H. Ford, and W. E. Lueschen.
1990. Effects of continuous and rotational cropping sequences on the yield of corn
and soybean. Submitted to Agron. J.
5* . Curtiss, C. F. 1926. Crop returns under various rotations in the Wisconsin drift soi1
area. Iowa College of Ag. and Mech. Arts, Bull. 241.
6.
Madden,P. and Dobbs,T.L. 1988. The role of economics in acheiving low- input /
sustainable farming systems. Paper prepared for Sustainable Agriculture Systems:
An international conference. Sept. 19-23, 1988. Colombus, Ohio. p l-36.
71 . Fuller, E., B. Lazarus, and D. Nordquist. 1989. What to grow in 1989. Crop
budgets for areas 2,4, and 5. Minnesota Ext. Serv., U. of MN.
A G - F S - 0 9 3 8 .
8. Daniel, T. C., and D. H. Mueller. 1986. Interaction of rotation and tillage on yield.
in:: Proc. Fertilizer, agricultural lime and pest management conference, Vol. 25.
Madison, WI, 21-23 January 1986. Cooperative Extension Program,
IJ of
Wisconsin, Extention service,
9. Hesterman, 0. B., M. P. Russelle, C. C. Sheaffer, and G. H. Heichel. 1987.
Nitrogen utilization from fertilizer and legume residues in legume-corn rotations.
Agron. J. 79:726-731
10. Higgs, R. L., H. P. Williams, J. W. Pendleton, A. F. Peterson, J. A. Jacob, and W.
D. Shrader. 1976. Crop rotation and nitrogen. U. of Wisconsin Res.
Bull. R.2761.
13
11 .Ja.nsen, H. H., D. J. Major, and C. W. Lindwall. 1987. Comparison of trop rotation
for sorghum production in Southern Alberta. Can. J. Plant Sci. 67:385-393.
12. Lazarus, W. F., L. D. Hoffinan, and E. J. Parheimer. 1980. Economie comparisons
of selected cropping systems on Pennsylvania cash trop and dairy farms with highly
productive land. Pennsylvania Agri. Exp. Stn. Bull. 828.
13. Peterson, T. A., and G. E. Varvel. 1989a. Crop yield as affected by rotation and
nitrogen rate. III. Corn. Agron. J. 81:735-738.
14.
. 1989b. Crop yield as affected by rotation and nitrogen rate. 1.
Soybean. Agron. J. 8 1:727-73 1.
15. Slife, F. W. 1976. Econornics of herbicide use and cultivar tolerance to herbicides.
Proc. Corn Sorghum Res. Conf. 31:77-84.
16. Statistical Analysis System Institute. In. 1985. SAS user’s guide: Statistics.
Version 3rd ed., SAS Institute Inc., Cary, N.C.
17. Sundquist, W. B., K. M. Menz, and C. F. Neumeyer. 1982. A technology
assessment of commercial corn production in the United States. Univers@ of
Minnesota. Ag. Ext. Stn. Bull. 546.
18. VO~S, R. D., and W. D. Shrader. 1979. Crop rotation. Effect on yield and
response to nitrogen. Iowa State University Cooperative Extension Service. Prn 905.
19. Welch, L. F. 1976. The Morrow plots. Hundred years of research. Ann. Agron.
27(5-6):881-890.
20. Zetner, R.P., and C.A. Campbell. 1988. First 18 years of a long term trop rotation
study in Southwestern Saskatchewan. Yields, grain, and economic performance.
Can. J. Plant Sci. 68:1-21.
1 4
Table 1. Cropping sequences maintained at Lamberton, Rosemount, and Waseca during
the six year period 1984 to 1989. (C=corn; S=soybean).
Treatment
1984 1985 1986 1987 1988 1989
----___--____
trop _ _ _ _ _ _ _ _ _ _ _ _ _
c c c c c c
s s
S
S
S
S
c s
c s
c s
c c s
c c s
S
S
c s
S
C
Table 2. 1989 prices of inputs used in the analysis
Seed
con-n
2 1 . 0 0
$ acre-l
soybean 9.00
1,
Fertilizer
N
0 . 1 2
$ Pound-l
P
0 . 2 2
11
K
0 . 1 4
II
Herbicide
Lasso
4 . 8 0
Lorox
12.10
Basagran 13.20
0
.
Crop oil5
7
$ pint-l
Insecticide
Furudan 8.70
$ ounce-l
Counter 8.70
IV
Lorsban 8.70
11
16
Table 3.
Estimated operating costs for cor-n and soybean grown at three locations in
Minnesota. From Fuller et al., 1989.
Lamberton
Rosemount
W a s e c a
Com Soybean
Com Soybean
Com Soybean
---------_______
$ acre-1 _ _ _ _ _ _ _ _ _ _ _ ._ _ - ._
Fuel
7 . 5 9
5 . 0 4
7 . 5 9
5 . 0 7
7 . 5 9
5 . 0 6
Repairs & Maintenace
19.79
14.98
19.79
15.00
19.59
14.97
Ether cash expensest
2 8 . 7 5
-
3 7 . 5 0
-
3 8 . 7 5
-
Enterest on cash exp.
7 . 5 6
4 . 6 6
8.71
4.60
8 . 6 7
4.38
Crop Insurance
6 . 0 4
6.65
8 . 0 6
7 . 1 8
8 . 1 4
7 . 1 8
Total
69.73
31.33
81.65
3 1 . 8 9
8 2 . 9 4
3 1.59
t harvest, drying, purchased irrigation, custom operations, technical services.
.
1 7
Table 4. Average grain yield of cropping sequences maintained at Lamberton, Rosemount.
and Waseca during the six year period 1984 to1989. (C=corn, S=soybean).
Lamberton
Year
Treatment
1984 1985 1986 1987 1988
1989
--__---- grain yield(bu. acre-‘) - - - .- - - - -
l.CCCCCC
133 160 136 140 54
137
2.ssssss
3.cscscs
127 183
42
:2 36
ii
;:
z;
4.ccsccs
127 170 35 149 70
3 9
5.sscssc
40 40 183 51 31
1 4 6
Rosemoun t
Year
Treatment
1984 1985
1 9 8 6
1987
1988
1989
-------- grain yield(bu. acre-l) - - - .- - - - -
l.CCCCCC
147
1 6 9
163
2 2
125
2. s s s s s s
3 9
2;
3.cscscs
156
1;:
4:
118
3 4
4.ccsccs
127
$5
40
1 6 9
7 0
4 0
5.sscssc
3 4
2 6
1 8 4
4 5
2 4
11
Waseca
Treatment
1 9 8 4
1985
1986 1987
1988
1989
- - - - - - - - grain yield(bu. acre-‘) - - - .. - - - -
l.CCCCCC
9 5
133
137
145
1 4 4
2.ssssss
3 0
2 5
3 9
4 1
29
3 9
3.cscscs
3 0
1 3 2
4 8
9 3
4 0
4.ccsccs
89
122
4 4
1 2 9
E
3 7
5.sscssc
3 2
2 7
133
46
1 9 4
Al1 locations combined
Year
Treatment
1984 1985
1986 1987
1988 1989
-------- grain yield(bu. acre-‘) - - - -. - - - -
l.CCCCCC
125
127
147
149
135
2. s s s s s s
3.cscscs
3 7
121
3 04
3 9
165
:::
78
94
37
4.ccsccs
1 1 4
1 2 9
4 0
1 4 9
27
3 8
5.sscssc
3 5
31
167
4 7
153
1 8
Table 5.
Average returns based on history of cropping systems (1984-1989)
location
locations
Treatments
Lamberton Wascea
Rosemount
combine4
- - - - - - - - return ($ acre-l year-l) - - - - - - - - -
cccccc
156 b
108 b
145 a
136 b
s s s s s s
14Oc
99 b
118 c
114 d
c s c s c s
159 b
95 b
147 a
134 bc
c c s c c s
156 b
91 b
123 bc
123 c
s s c s s c
188 a
155 a
138 ab
160 a
C.V. (%)
6.5
18.0
8 . 4
10.4
-
-
*
Within each column means with the same letter are not significantly different at
the 0.05 probability level according to Duncan’s Multiple Range Test.
1 9
Table 6. Returxoperating cost ratios of the fïve cropping systems.
Treatments
Lamberton
Rosemount
Waseca
- - - - - - _ ratio* _ _ _ _ _ _ _ _ ,_ - -
1 - c c c c c c
-;.06
0.57
0.88
2 - ssssss
1.87
1.03
1.50
3 - c s c s c s
1.37
0.63
1.20
4 - c c s c c s
1.28
0.61
0.89
5 - s s c s s c
1.82
1.29
1.29
* ratio =
return ($/acre/yearI
operating cost ($/acre/year)
Table 7. Average annual prices paid to Minnesota fax-mers.
l?rice of
SoybeanCorn
Year
C O
Soybean
mice ratio
_ _ ?$ bushel-1 _ _ _
1975
2.50
5.02
2.01
1 9 7 6
2.03
7.22
3.55
1977
1.90
5.90
3.11
1978
2.08
6.52
3.13
1 9 7 9
2.26
2.65
1 9 8 0
2.85
7”~~
2.54
1981
2.33
5:77
2.48
1 9 8 2
2.63
5.81
2.21
1983
3.05
7.64
2.50
1 9 8 4
2.47
5.60
2.27
1985
2.05
4.98
2.43
1 9 8 6
1.46
4.72
3.29
1987
1.55
5.70
3.68
1988
2.35
5.50
2.34
1989
2.40
5.80
2.42
Mean
2.70
Std. Dev.
0.50
L Q W
2.01
High
3.68
Source: Minnesota agricultwal statistics
(prices do not include government support).
2 1
Table 8. Sensitivity analysis: returns above operating costs ($/acre/year) for selected
com prices and soybeaxcorn (S:C) ratios at Larnberton, Rosemount, and Waseca.
Com mice = $1,46/bu (10~1
Lamberton
Rosemounl
l!!!as2
S:C ratio
S:C ratio
-S:C.r:atio..
Treatments
2.2
2.7
3.2
2.2
2.7
3.2
2.2
2.7
3.2
-------__-----------
$ acre-l yem-l_ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ I _ _ _ _ . _ _
1. c c c c c c
37b*
37d
37d
24bc
24b
24 d
-. 8 c
“’ 8 c
.’ 8 c
2. ssssss
41 b
69 b
97a
30 ab
55 a
75 a
12 b
:36 b
61 a
3. cscscs
45 b
5oc
76c
36 a
49a
62b
-,4bc
lOc
25 b
4. ccsccs
43 b
6Obc
61~
16 c
26b
36~
-’ 8 c
3 c
13bc
5. s s c s s c
65 a
85a
105 a
36 a
51 a
67 b
39 a
:58 a
78 a
C.V. (%)
14
11
9
24
18
14
:100
"70
55
Corn txice = $2,4O/bu (mediuml
Lamberton
Rosemount
waseca
S:C ratio
S:C ratio
-$:C.e_
Treatments
2.2
2.7
3.2
2.2
2.7
3.2
2.2
2.7
3.2
~.----_-
___________------___ $acre-l ye*-l_____ I _____ -__ ___.. _____. __
1 . c c c c c c
156b* 1 5 6 b 1 5 6 d
145a 145ab 145b
1108 a
i108b ‘108~
2. ssssss
1'21~
167b
213b
101 c
141 ab 189a
81 b
1120 b
‘162 b
3. cscscs
148b 173’b 198b
138 a
160a
181 a
8 4 b itO8b 1131bc
4. ccsccs
1 4 9 b 164’b 179~
116bc 132b 148b
8 4 b 1:OOb .117c
5. sscssc
173a
203,a
238a
127ab 152a
178 a
1.41 a
IL'73 a
206 a
C.V. (%)
7
6
6
9
8
7
18
18
19
Com mice = $3.05/bu (hiph)
Lamberton
Rosemount
wctseca
S:C ratio
S:C ratio
-$:Cratio..
Treatments
2.2
2.7
3.2
2.2
2.7
3.2
2.2
2.7
3.2
-------------w----me$ acre-l ye=-l _ _ _ _ _ I _ _ _ _ _ _ _ _ _ _ _ _. _ _ _ ._ _ _ _ _
1. c c c c c c
239 ab* 239 ‘b
239 c
229 a
229 ab 229 b
1188 a
1188 b
l88 b
2. ssssss
176~
239'b
294 b
149d
201 c
253 a
1129b
K80b
231b
3. cscscs
219b
25lb 284b
209ab 236a
264a
1147 b
1175 b
205 b
4. ccsccs
2 2 3 b 2 4 1 b 260~
185~ 206b 2 2 6 b
1145 b 168 b ‘189 b
5. s s c s s c
247a
289~1
330a
191 bc 223 abc 256 a
Z!ll a
253 a
294 a
C.V. (%)
6
6
5
7
7
6
14
14
15
* within each column means with the same letter are not significantly different at the 0.05 probabilky
level according to Duncan’s multiple range test.
22
Table 9. Ranking of retums for fïve cropping systenw at Lamberton, Waseca, and Rose-
mount for different combinations of com prices, and com:soybean price ratios.
Lamberton
Com Price
--.--_-
($1.46lbuI
Low
Med($2.40/bu)
1lip-h ($3.05/bul
Soybea x0 atio
Sovbea .com ratio
S lybea xom rab
2.2
2n:7 m 3.2
2.2
2n:7
3.2
2’2
z.7
3.2
Treatment
-.-.-
- - - - - - - - - - - - - - - - - - - - r&&g* - - - - - - _ - _. I _ - - ,.. _- - - .- -
1 - c c c c c c
5 5 5 2
5
2!
4;
,c-
2 - s s s s s s
4 3 2 5
3
2
5;
4
IL;
3 - c s c s c s
2 4
2
4 2
13
4 ‘- c c s c c s
3 4
:
3
4
:
3
-1
3
4
5 - s s c s s c
1 1 1 1
1
1
1
1
1.
Rosemount
C o m P r i c e --_--_-
Low ($1.46/bul
Med($2.40/bu)
High ($3.05/buj
Sovbeanxom ratio
Sovbeaxcom ratio
~ovbeaxcom rat&
2.2
2.7
3.2
2.2
2.7
3.2
2.2
2.7
3.2
- - ra&ipg*
- - - - - - - - _. - - - - . - - - - <_ -
I!,
1
2 _- cccccc
ssssss
------;----;-----i
3 3 3 4
4
51
1zi
‘V
5
<-
‘”
.;;
3 - c s c s c s
2
-1
1
1
4 - c c s c c s
: 4 4
3
:
4
ii
4
5
5 - s s c s s c
2 2 2
2
3
2;
3
‘3
Waseca
Com Price
--~-_-
Low ($1.46/bu)
Med($2.40/bu)
High ($J.OS/bu~
Soybeanxom ratio
Sovbean:com ratio
Sovbeanxom ratio
2.2
2.7
3.2
2.2
2.7
3.2
2.2
2.7
3.2
Treatment
-
-
-
-
-
-
-0_________________- r&hg* - - - - - - - - _. - - - - . . - - . . - - -
1 - c c c c c c
5 2
4
5
2!
‘7
.!,
!5
2 - s s s s s s s
2 2
;
;
2
2
2;
3
1-
7
3 - c s c s c s
3 3 3
3
3
4
4
3
4 - c c s c c s
4 4 4 4
5
4
3
15
4
5 - s s c s s c
1 1 1 1
1
1
l
Ii
l
* ranking of 1 = the most profitable sequence; 5 = the least profitable sequence.
Appendix 1: Rates of inputs applied on plots at Lamberton, Rosemoun t, and Waseca
from. 1984 to 1989
Fertilizer (# per acre)
Herbicides (#peracre)
Insecticides (ozper 1100 ft 11
N* P K
lasso lorox basagran oil
furadan counter losban
LAMBERTON
1984
125 100 100
2.5
2 . 5
-
._
1985
125 100 100
2.5
1.5
-
._
1986
125 -
-
2.5
1.5
-
._
1987
125 -
-
3 . 0
1.5
-
._
1 .O
1988
125 100 100
2.5
1.5
-
._
1.0
1989
130-
-
3 . 0
1.5
-
R O S E M O U N T
1984
_
_
_
-
-
-
<_
1985
160 -
-
2 . 5
-
1.0
._
1 .O
1986
160 -
-
2.5
-
1.0
.-
1 .O
1987
180 -
-
2.5
-
1.0
2 . 0
1 .O
1988
170 -
-
-
-
-
2 . 0
1 .O
1989
160 -
-
2.5
-
1.0
2.0
W A S E C A
1984
163 -
-
3.5
1.5
-
2 . 0
1.0
1985
175 -
-
-
-
-
2 . 0
1.0
1986
175 -
-
3 . 0
1.5
-
2 . 0
1.0
1987
175 -
-
3.5
1.5
1.0
2 . 0
1.0
1988
163 -
-
3.5
1.5
-
2 . 0
1 .o
1989
163 -
-
3,5
1.5
1.0
2 . 0
* Nitrogen was applied only on plots planted to com.
2 4
Appendix 2: Soil ‘characteristics
Lamberton: Webster: fiie loamy. mixed.Typic Hanluquoll
-slope O-3%
-poorly drained soi1 on glacial moraines
-surface layer black granular or blocky, friable clay loam or loam 14 to 16 inches
thick
-subsurface layer very dark gray to olive gray, friable clay loam 19 to 21 inches
thick, certain few mottles
underlaying material strongly mottled, gray calcareous loam, substrats with, many
lime concretions, 32to37 inches thick
-available water capacity: 15.6 inches to 5 feet
-high organic mater: 67%
-moderately permeable
Waseca: Nicollet: fine loamv. mixed.Aauic Hanludoll
-slope: O-2%
-moderately well draïned soi1 on the uplands
-surface layer black to very dark grayish brown clay loam 8 to 16 inches thick
-subsurface dark grayish brown clay loam 2 5 to 35 inches thick
-underlaying material olive gray calcareous loam or clay loam
-avalaible water capacity: 9.5 inches to 5 feet
high organic mater: 6%
-moderately permeable
Rosemount: Waukegan: fine silt loam. mesic.Typic Hapludoll
-slope: 2-6%
-well drained soil
-surface layer black silt loam about 14 inches thick
-subsurface layer dark grayish brown silt loamabout 3 inches thick
-underlaying material dark brown sand about 4 inches thick
-avalaible capacity: 10.7 inches to 40 inches
-organic mater: 2-6%
-moderately permeable in uuper mantles and rapid in underlaying soif and bedrock
_-__._._
_-..___-..“-.+----.__1_1-I
_.___
-
_,._.
_-_,
----
____ ;z
-_____. ._-_
I-_.------. _,_ l-..-*.---..-.~
__-____
_-._-.-.. .-----
.-m---------
2 6
Appendix 3.1 Soi1 levels of extractable phosphorus and exchangeable potassium
as affected by trop history.
LAMBERTON
Crop to be plauted
C
S
S
C
S
No.of years of C out of previous 5
5
3
2
1
0
No.of yeasr of S out of previous 5
0
2
3
4
5
Soi1 P(lb.acre-1)
50
51
54
57
57
Soil K (lb.acre- 1)
263
277
330
310
330
ROSEMOUNT
Crop to be plauted
C
S
S
C
S
No.of years of C out of previous 5
5
3
2
1
0
No.of years of S out of previous 5
0
2
3
4
5
Soi1 P(lb.acre-1)
68
60
81
70
83
Soil K(lb.acre- 1)
257
268
276
L!79
316
WASECA
Crop to be plauted
C
S
S
C
S
No.of years of C out of previous 5
5
3
2
1
0
No.of years of S out of previous 5
0
2
3
4
5
Soi1 P(lb.acre-1)
69
88
76
79
88
Soil K(lb.acre-1)
388
397
406
409
411
ALL LOCATIONS COMBINED
Crop to be plauted
C
S
S
C
S
No.of years of C out of previous 5
5
4
3
1
0
No.of years of S out of previous 5
0
2
3
4
5
Soil P(lb.acre-1)
62
66
70
69
76
Soil K(lb.acre- 1)
303
314
337
322
352
Imnortant noin&
1.
Com monocullture reduced soi1 P and K levels as compared to soybean monoculture.
2 .
lhere was a trend of increasing soi1 P and K with decreasing frequency of years of
com during the last 5 years.
27
Appendix 3.2: Com (C) and soybean (S) leaf concentration of P and K: at flowering
(com=silking, soybean=R3) in 1989.
Lamberton
Rosemount
Waseca,
P
K
P
K
P
K
s . . . . . . . . . . . . . . . . . . . . . . . g.kg-l,........,...... . . . . . . . .
Continuous C
3 . 0
17.8
3.5 12.9
2 . 9
17”O
C after 2 of
years
S
2 . 9
18.0
3.5 12.9
2 . 8
17.0
Continuous S
4 . 5
18.9
6.5 21.8
6 . 0
2 1 . 9
S after 1 of
year
C
4 . 6
19.9
6.7 21.8
5.7
21..9
S after 2 of
years
C
4 . 5
18.5
7.0 23.0
6.1.
2 2 . 7
Important point
Com and soybean leaf concentration of P and K was not affected by the rotation history.
28
Anuendix 3.3: Leaf concentration of Ca, Mg, Fe, Mn, Zn, CU, and B in com (silking
stage) and soybean (R3 stage) plants in 1989.
LAMBERTON
Ca Mg
Fe Mn
zl CU
l3
. ..g.g-l...
. . . . . . ...” . . . . . . .
IXtg.g-l................
Continuous C
5.6 4.7
124.5
5 5 . 0
23.5
9 . 5
6.3
C after 2 years of S
5.2 4.5
133.0
5 5 . 0
2 4 . 0
10.3
‘6.6
Continuous S
8.4 4.4
9 2 . 3
4 1 . 5
32.5
7.0
3 7 . 0
S after 1 year of C
8.3 4.2
9 0 . 5 4 4 . 5
3 2 . 5
7.0
3 6 . 0
S after 2 years of C
8.5 4.4
9 3 . 0
4 1 . 5
3 2 . 0
7.0
37.5
ROSEMOUNT
Continuous C
6.7 8.1
154.0
5 4 . 0
2 2 . 0
11.0
6 . 0
C after 2 years of S
6.8 8.3
162.0
5 7 . 0
2 3 . 0
10,5
5.5
Continuous S
10.2 5.3
9 8 . 3
5 9 . 0
42.0
40.0
S after 1 year of C
9.2 5.1
9 5 . 8
57.0
4 3 . 3
;:5
3 9 . 0
S after 2 years of C
9.3 5.1
9 5 . 0
5 4 . 0
4 5 . 5
1010
38.5
WASECA
Continuous C
4.9 4.1
150.0
2 7 . 0
2 5 . 0
8 . 0
5 . 0
C after 2 years of S
5.0 4.4
128.5
2 5 . 5
22.5
8.,8
s.5
Continuous S
10.3 4.9
101.0
44.0
41.5
4 7 . 5
S after 1 year of C
10.3 4.7
101.5
4 7 . 0
4 2 . 5
9*3
4 6 . 5
S after 2 years of C
10.0 4.5
9 6 . 5
4 6 . 3
4 1 . 5
9:5
47.:5
Imnortant noints
1 .
Com and soybean concentration of Ca, Mg, Fe, Mn, Zn, CU., and B was not affected
by the rotation history.
2 .
Ca and B concentration was greater in soybean leaves than in com leaves.
3 .
Fe concentration was higher in com leaves than in soybean leaves.
A THESIS
SUBMITIED TO THE GRATUATE SCHOOL
OF THE UNIVERSI’IY OF MINNESOTA
Marnadou Ndiaye
IN PARTIAL FULFILLMENT OF THE REQUIREMENTS FOR THE DEGREE
o f
MASTER OF SCIENCE
May, 1990
A C K N O W L E D G E M E N T S
Most gracious thanks to Dr. Robert Kent Crookston for his guidance as an advisor,
his encouragement troughout the study and the course program, and his tremendous help
in the writing of this thesis. Thanks to Jim Kurle who taught me how to use and to t-un
computer programs for the a.nIysis of the experiment. Thanks are extended to fellow
menbers of the Crop Production Project. Sincere thanks to Drs. R. Stucker and. V. B.
Cardwell for their assistance, suggestions, and comments on the proposa1 and the analysis
of the thesis. Cordial gratitude to the Department of Agronomy and Plant Genetics staff
and the State. of Minnesota for providing facilities and resources for the research. Thanks
to Drs. Pierre Robert, Jeffrey Apland, and Dale Hicks for reviewing the thesi:s, offering
constructive comments, and serving on the examining committee. Sincere appreciation and
thanks are addressed to all friends in the IJ.S.A. for their encouragement and. support.
Gratitude goes to my lovely sisters and Senegalese friends for their invaluable help
throughout my stay in the U.S.,A. Gratitude goes to the “Institut Senegalais de
Recherches Agricoles” and to The Govemment of Senegal.
ii
FOEWARD
This thesis is written as an manuscript to be submitted to the Journal of&duction
&riculture. It is followed by appendixes containing information about soi1 and plant
nutrients not directly referred to in the manuscript.
. . .
111
“.“l*lll--,-l.“.~-l..-.l-.-..
-----*-
__.-
--.-.
_pv-mp--.-.
.-
-
--
..“-..i
_._.”
----,--.----
F O R E W A R D
This thesis is written as an manuscript to be submitM to the Journal oL&oduction
Aticulture. It is followed by appendixes containing information about soi1 and plant
nutrients not directly referred to in the manuscript.
iv
1
TBLE OF CONTENTS
Page
Abstract
2
Literature review-Objectives
3
Mater&& and Methods
5
Results and Discussion
7
Conclusion
1 1
References
12
Tables
14
Appendix 1
2 3
Appendix 2
24
Appendix 3
2 5
Appendix 3.1
2 6
Appendix 3.2
2 7
Appendix 3.3
2 8
_- _._..,-
ASTI_
-__.---.-
__.I-._.-l-_-,.ll<
--.----
-,-w.--
___
--“-
” -.-..-..
x “I...__
.-_-_-.~--,~
2
AE3STRAcT
Com and soybean grown in sequence is one of the most popular cropping systems
in the United States; the com-soybean rotation has enormous importance economically. O
The “rotation effect” is known to increase yields of both crops, but little is known
about the economic consequences of various corn -soybean rotational patterns compared
with monoculture. This study was undertaken to determine the most profitable
com-soybean cropping pattern for Minnesota, based on both actual and sensitivlty price
analyses. Rotations investigated were: corn monoculture, soybean monoculture, corn
grown after two years of soybean, soybean grown after two years of com, a.nd an annual
alternation of the two crops. The field study was conducted at three locations: Lamberton,
Rosemount and Waseca, MN. Lamberton and Waseca are positioned within the “com
belt,” whereas Rosemount is positioned beyond the northerly fiinge. Actual analysis
(1984-1989) indicated that com following two years of soybean was the most profitable
cropping system at both com-belt locations. At Rosemount there was no cle.ar net-return
pattem. Averaged over all locations, com following two years of soybean was definitely
,the most profitable cropping system however. Soybean monoculture provide:d the lowest
,average retum, and com monoculture had the lowest returmoperating cost ra.tio at a11
locations. Projection analysis indicated that com after two years of soybean would be the
most profitable com-soybean rotation in the Minnesota com belt under ail expected com or
soybean price combinations. Com monoculture was projected to be the least profitable
pattem, and soybean monoculture the second least profitable pattem. Rrices did not
include govemment supports.
__,,._.
__._~
,-m-,
-*
--
.
.
. ““--.“,_
--
3
LITERATURE REVIEW - OBJECTIVES
In the United States, the annual rotation (alternation) of corn and soybe’an is a very
c:ommon cropping system (Sundquist et al., 1982). Both com and soybean yield better
when grown on land previously sown to the other trop than when grown continuously
(Higgs et al., 1976; Slife, 1976; Peterson and Varvel, 1989a and 1989b). In l.ong term
s.tudies conducted at Waseca and Lamberton, Crookston et al. (1990) found th.at compared
with monoculture, either com or soybean yielded an average of 8% better when altemated
and about 16% better when kept out of monoculture for at least two years.
Early in the 20th Century, Amy (19 17) reported a higher net income per acre from
com grown after legumes than grown continuously. Later, Curtiss (1926) demonstrated
that a rotation of four or five years was of more value than a shorter three-year rotation
which was defiiitely preferable to a two-year system or to continuous cropping. Recently,
the beneficial effect of rotation versus continuous monoculture of com and soybean has
been estimated in the U.S. to be worth at least 300 million dollars annually (Sundquist et
aI., 1982). Crookston (1984) has shown that Minnesota. farmers cari raise th.eir net profit
on com and soybean by as much as 50% tiom properly exploiting the rotation effect.
Daniel and Mueller (1986) found that com-soybean rotation increased the net profit in the
com year and in the soybean year by $36.00 and $20.00 per acre, respectively. In
contrast, Voss and Shrader (1979) reported that continuous com was among the most
profitable systems, depending on the economic values assigned to the crops. Lazarus et
al.( 1980) found greater annual returns from continuous com than from a rotational
com-soybean system .
Conflicting results about the economics of com-soybean rotation systems justified a
closer look at the rotation effect, particularly in terrns of net return to the farmer. The first
objective of this study was to compare the profitability of fîve diiferent com-soybean
. . ..- a.*lmlll
-. -. -
,__-__
--._.^ -.-<.-. “. _I--~*IsIQII*vI.mB e-
cropping sequences over the six-year period 1984-1989 in Minnesota. The second
objective was to predict the most profitable htinesota corn-soybean cropping pattern for
the forseeable future via simulated scenarios based on expected fluctations in commodity
prices.
MATERLALS ANDMETHODS
A six-year trop rotation study was established in 1.984 at the Southwest Experiment
Station at Lamberton, at the Rosemount Experiment Station, and at the Southelm
E,xperiment Station at Waseca, Minnesota. The soils at these locations are : Wlebster clay
loam, Waukegan silt loam, and Nicollet clay loam, respectively. The corn hybrid was
‘Pioneer Brand 3780’ and the soybean variety was ‘Hodgson 78’.
Each experimental area was chisel plowed each fall. Fertilizer N (urea or ammonium
nitrate), P (superphosphate), and K (potash) were applied according to University of
h4innesota soi1 test recornrnendations for maximum production of each trop. Herbicides:
alachlor (lasso), linuron (lorox), and bentazon (basagran); and insecticides: carbofuran
(furadan), terbutos (counter), and chlorpyrifos (lorsban) were applied when necessary for
weed and insect control.(appendix 1).
Five different corn and/or soybean cropping sequences (Table 1) were ‘arranged in a
randomized complete block design replicated four times. Each plot consisted of eight rows
30 feet long spaced 30 inches apart. There were four replications at each location each
year. Grain yield was obtained by harvesting the two tenter rows from each plot. Yield
values were corrected for moisture (reported at 15.5%, and 13.5% moisture for corn and
soybean, respectively).
Investigating the economic implications of any agricultural practice requires research
on the individual components of a farm, the whole farm, commodity markets, national and
international agricultural economies,etc. (Madden and Dobbs, 1988). In accessing
incentives to adopt trop rotation sequences, various factors must be accountered. for.
Complete enterprise budgets may include all fixed and variable cost and returns associated
with the farm. According to Boehlje and Eidman (1984 ) “The distinction between fixed
and variable costs is imporatnt in decision -making. Only variable costs should be
6
considered by the manager in deciding what to produce, how to produce and ‘how much to
produce in the short run. Fixed costs Will remain at the same level regardless of these
Idecisions. Thus, neither fïxed cash nor non cash costs should be considered in
decision-making”.
Our approach was to deal with the operating costs and net returns
associated with production activities of a typical Minnesota farrn. We assumed that trop
sequence was the only aspect of the farm that varied. Such an economic approach may
suffïce for decision-making in the area of adopting more valuable trop sequences.
Operating costs specifïcally associated with either corn or soybean, and incurred for the
production of that trop were considered. According to our particular situation, adjustmenrs
were made by accurately determining the cost of fertiliser, seed, herbicide, and insecticide
(table 2). Other operating costs were taken from “What to grow in 1989” (FUer et al.,
1989) (table 3). Ail operating costs were based on 1989 prices. Revenue per acre was
calculated on the basis of the yield of com and / or soybean multiplied by the product price.
Operating costs were charged against revenues to obtain per acre net returns. Statistical
analysis was via the General Linear Procedure of Statistical Analysis System (SAS, 1985),
A variety of possible net return scenarios were also calculated for a range of com
and soybean price combinations. Price combinations were based on com and soybean
prices for the 15-year period 1975 to 1989; costs and expenses were maintained at 1989
levels.
7
RESULTS AND DISCUSSION
Economie analvsis based on 1989 dollar value
The annual grain yield of the fïve cropping systems are given in table ,4. Enterprise
budgets for the six year period 1984- 1989 were based on actual yields of com. and soybean
grain for each year, and on the 1989 prices for com and soybean of $2.40 and $5.85 per
bushel, respectively. Operating costs were also fixed at 1989 values.
Over the six years, retums at Lamberton ranged from $140 per acre per year for
continuous soybean to $188 per ac,re per year for com grown after two successive years of
soybean (Table 5). Com following two years of soybean provided a significantly greater
retum than any other cropping system. Retums obtained from com monoculture,
altemated com and soybean, and soybean grown after two years of com were not
significantly different. Soybean monoculture provided the lowest retum.
Waseca results were similar to those obtained at Lamberton. Retums varied from
$9 1 per acre per year for soybean grown after two years of com, to $155 per acre per year
for com grown after two years of soybean. Com after two years of soybean provided a
signiflcantly g-mater retum than any other cropping system. There were no sign:ifkant
differences among the remaining cropping pattems.
At Rosemount, retums ranged from $118 per acre per year for continuous soybean
to $147 per acre per year for the altemate com-soybean system (Table 5). Continuous corn
and an annual rotation of com and soybean provided nearly equally high retums;
continuous soybean provided the lowest retum. Over all locations, retums ranged from
$119 per acre per year for continous soybean to $160 per acre per year for com following
two years of soybean (Table 5). Com after two years of soybean retumed $33 per acre per
year more than the average of all other sequences. Continuous soybean was the least
profitable system and retumed $24 per acre per year less than the average of a11 other
sequences. The difference between the most profitable system (SSCSSC) and the least
8
profitable system (SSSSSS) was $46 per acre.
The fact that results from Rosemount were SO different from the other two locations
is worthy of some discussion. Rosemount is located north of the other two sites, and has
a strikingly different soi1 type (appendix 2). Soils at the three locations are classified as
follows: Lamberton, Webster clay loam (fine, loamy, mixed, mesic Typic Haplaquoll),
Waseca, Nicollet clay loam (fine, loamy, mixed, mesic Aquic Hapludoll) ; Rosemount,
Waukegan silt loam (fine, silty over sandy, skeletal, mixed, mesic Typic Hapludolls) ).
Soi1 depth at both Lamberton and Waseca is greater than 6 feet, whereas soi1 depth at
Rosemount is about 20 inches below. Lamberton and Waseca are located well within the
“com-belt” region of Minnesota, whereas Rosemount lies beyond the northem fringe. The
Lamberton and Waseca results thus represent. typical com-belt soi1 and climatic conditions,
whereas the Rosemount results better represent more marginal conditions.
Corn after two successive years of soybean was the most profitable cropping
sequence at both Lamberton and Waseca. Hesterman et al. (1987) demonstmted higher
gross margins for com and soybean in rotation than for continuous com at these same
locations. Results obtained by some authors have shown that gross retums were
significantly influenced by rotation in comparison with monoculture (Zetner and Campbell.
1988; Jansen et al.,1987). Our results contradict those of Lazarus et al. (1980) who
concluded that monoculture of com was more profitable than rotation.
TO estimate the relative efficiency of each cropping sequence, we calculated
retumloperating- cost ratios (Table 6). A low value for this ratio represents a situaton
which could contribute to cash flow problems for some farmers. At Rosemount, for
example, retums from continuous com, alternate com-soybean, and com after two years
of soybean were quite low. Continuous com had the lowest return/operating cost ratio for
all locations (Table 6). If credit is limited, farmers would certaintly consider crops with
highest ne.t retum-operating cost ratios, which give enough net retum to caver operating
costs incurred.
9
Sensitivitv analvsis based uoon combinations of com and sovbean priceg
The average retums in Table 5 were based on actual yields, prices and costs during
the period 1984-1989. While these retums may be of interest from a historical standpoint,
they are of limited value in projecting future retums even from these same cropping
sequences in these same locations. In order to obtain some estimate of expected retums
from com and soybean grown in various sequence combinations on these sites in the
future, we developed several expected-retum scenarios based on projected yields and
prices at these sites. Yields for the scenarios were the yields from this six-year
(1984-1989) study. Costs were 1989 costs. Prices were derived from average com and
soybean prices in Minnesota over the 15year period 1975 1989 (Table 7).
From Table 7, we chose the lowest (1986) price of $1.46 per bushel, the highest
(1983) price of $3.05 per bushel, and a somewhat medium (1989) price of $2.40 per
bushel for com. We then used the 15-year average soybeamcom ratio of 2.7 for a medium
ratio. High (3.2) and low (2.2) ratios were determined by adding and subtracting the
YS-year ratio standard deviation. This provided nine com-soybean price combinations
which we considered to reflect prices likely to be encountered in the future.
With a low com price, com following two years of soybean provided the
consistently highest projected retums at both Lamberton and Waseca regardless of the
soybean:com price ratio (table 8). Continuous soybean also provided a high. retum when
the soybean:com price ratio was 3.2. At Rosemount there was no clear net retum pattem,
except that continuous com provided the lowest retum under all soybean:com price ratios.
With a medium com price, com following two years of soybean again provided the
consistently highest projected retum at both Lamberton and Waseca. At Rosemount, there
was once again no clear trend (table 8).
With a high com price, highest retums again carne from the SSCSSC cropping
sequence at both of the com-belt (Lamberton and Waseca) sites, regardless of the
10
s~ybean:com price ratio (table 8). At Rosemount, there was no clear pattern.
In order to better visualize the projected performance of the five sequences, the
results of each com price and soybeamcom price ratio combination were portrayed by rank
(Table 9). The superiority of the SSC pattem at the Lamberton and Waseca locations is
clear. It cari also be seen that continuous com achieved tbe number 5 ranking more than
any other sequence at these two locations. With only two exceptions, whenever
continuous com was not ranked 5th, continuous soybean fïlled the number 5 rank. In the
two exceptional situations, the 5th ranked sequence was CCS. Thus it is clear that
monoculture of either trop, but especially of com, is likely to result in lowest retums for
farmers in the Minnesota com belt unless future prices fluctuate considerably from the
1975- 1989 pattem.
At Rosemount, there was no clear ranking trend. CSCSCS was projected to be
more profitable four times, SSSSSS three times, and CCCCCC two times. The CCSCCS
and SSCSSC sequences were never projected to be most profitable.
11
C O N C L U S I O N
This study was conducted under the condition of trop selection being limited to com
and soybean, with resulting cropping systems being some sequential combinations of these
two crops. We conclude that choice of com soybean cropping sequence cari be of
considerable economic importance for Minnesota farmers. The sequence of
soybean-soybean-com (S S C) clearly was (and is projected to be) the most profitable
sequence across a11 locations, but especially at the two com-belt locations. However, not
all farmers in the state cari adopt such a system, other factors, particularly government
prices Will influence trop selection.
1 2
REFERENCES
1.
Amy, A. C. 1917. Crop rotation investigation field experiments. University of
Minnesota Ag. Exp. Stn., Bull. 170.
3
Ad. Boehlje,M.D.,and V.R.Eidman. 1984. Farm management. Ed. John Willey &
Sons New York. Chichester. Brisbane. Toronto. Singapore.
3.
Crookston, R. K. 1984. The rotation effect: what causes it to boost yields? Crops
and Soils Magazine. 36(6)12- 14. Am. Soc. Agron., Madison, WI.
4.
Crookston, R. K., J. E. Kurle, P. J. Copeland, J. H. Ford, and W. E. Lueschen.
1990. Effects of continuous and rotational cropping sequences on the yield of corn
and soybean. Submitted to Agron. J.
5* . Curtiss, C. F. 1926. Crop returns under various rotations in the Wisconsin drift soi1
area. Iowa College of Ag. and Mech. Arts, Bull. 241.
6.
Madden,P. and Dobbs,T.L. 1988. The role of economics in acheiving low- input /
sustainable farming systems. Paper prepared for Sustainable Agriculture Systems:
An international conference. Sept. 19-23, 1988. Colombus, Ohio. p l-36.
71 . Fuller, E., B. Lazarus, and D. Nordquist. 1989. What to grow in 1989. Crop
budgets for areas 2,4, and 5. Minnesota Ext. Serv., U. of MN.
A G - F S - 0 9 3 8 .
8. Daniel, T. C., and D. H. Mueller. 1986. Interaction of rotation and tillage on yield.
in:: Proc. Fertilizer, agricultural lime and pest management conference, Vol. 25.
Madison, WI, 21-23 January 1986. Cooperative Extension Program,
IJ of
Wisconsin, Extention service,
9. Hesterman, 0. B., M. P. Russelle, C. C. Sheaffer, and G. H. Heichel. 1987.
Nitrogen utilization from fertilizer and legume residues in legume-corn rotations.
Agron. J. 79:726-731
10. Higgs, R. L., H. P. Williams, J. W. Pendleton, A. F. Peterson, J. A. Jacob, and W.
D. Shrader. 1976. Crop rotation and nitrogen. U. of Wisconsin Res.
Bull. R.2761.
13
11 .Ja.nsen, H. H., D. J. Major, and C. W. Lindwall. 1987. Comparison of trop rotation
for sorghum production in Southern Alberta. Can. J. Plant Sci. 67:385-393.
12. Lazarus, W. F., L. D. Hoffinan, and E. J. Parheimer. 1980. Economie comparisons
of selected cropping systems on Pennsylvania cash trop and dairy farms with highly
productive land. Pennsylvania Agri. Exp. Stn. Bull. 828.
13. Peterson, T. A., and G. E. Varvel. 1989a. Crop yield as affected by rotation and
nitrogen rate. III. Corn. Agron. J. 81:735-738.
14.
. 1989b. Crop yield as affected by rotation and nitrogen rate. 1.
Soybean. Agron. J. 8 1:727-73 1.
15. Slife, F. W. 1976. Econornics of herbicide use and cultivar tolerance to herbicides.
Proc. Corn Sorghum Res. Conf. 31:77-84.
16. Statistical Analysis System Institute. In. 1985. SAS user’s guide: Statistics.
Version 3rd ed., SAS Institute Inc., Cary, N.C.
17. Sundquist, W. B., K. M. Menz, and C. F. Neumeyer. 1982. A technology
assessment of commercial corn production in the United States. Univers@ of
Minnesota. Ag. Ext. Stn. Bull. 546.
18. VO~S, R. D., and W. D. Shrader. 1979. Crop rotation. Effect on yield and
response to nitrogen. Iowa State University Cooperative Extension Service. Prn 905.
19. Welch, L. F. 1976. The Morrow plots. Hundred years of research. Ann. Agron.
27(5-6):881-890.
20. Zetner, R.P., and C.A. Campbell. 1988. First 18 years of a long term trop rotation
study in Southwestern Saskatchewan. Yields, grain, and economic performance.
Can. J. Plant Sci. 68:1-21.
1 4
Table 1. Cropping sequences maintained at Lamberton, Rosemount, and Waseca during
the six year period 1984 to 1989. (C=corn; S=soybean).
Treatment
1984 1985 1986 1987 1988 1989
----___--____
trop _ _ _ _ _ _ _ _ _ _ _ _ _
c c c c c c
s s
S
S
S
S
c s
c s
c s
c c s
c c s
S
S
c s
S
C
Table 2. 1989 prices of inputs used in the analysis
Seed
con-n
2 1 . 0 0
$ acre-l
soybean 9.00
1,
Fertilizer
N
0 . 1 2
$ Pound-l
P
0 . 2 2
11
K
0 . 1 4
II
Herbicide
Lasso
4 . 8 0
Lorox
12.10
Basagran 13.20
0
.
Crop oil5
7
$ pint-l
Insecticide
Furudan 8.70
$ ounce-l
Counter 8.70
IV
Lorsban 8.70
11
16
Table 3.
Estimated operating costs for cor-n and soybean grown at three locations in
Minnesota. From Fuller et al., 1989.
Lamberton
Rosemount
W a s e c a
Com Soybean
Com Soybean
Com Soybean
---------_______
$ acre-1 _ _ _ _ _ _ _ _ _ _ _ ._ _ - ._
Fuel
7 . 5 9
5 . 0 4
7 . 5 9
5 . 0 7
7 . 5 9
5 . 0 6
Repairs & Maintenace
19.79
14.98
19.79
15.00
19.59
14.97
Ether cash expensest
2 8 . 7 5
-
3 7 . 5 0
-
3 8 . 7 5
-
Enterest on cash exp.
7 . 5 6
4 . 6 6
8.71
4.60
8 . 6 7
4.38
Crop Insurance
6 . 0 4
6.65
8 . 0 6
7 . 1 8
8 . 1 4
7 . 1 8
Total
69.73
31.33
81.65
3 1 . 8 9
8 2 . 9 4
3 1.59
t harvest, drying, purchased irrigation, custom operations, technical services.
.
1 7
Table 4. Average grain yield of cropping sequences maintained at Lamberton, Rosemount.
and Waseca during the six year period 1984 to1989. (C=corn, S=soybean).
Lamberton
Year
Treatment
1984 1985 1986 1987 1988
1989
--__---- grain yield(bu. acre-‘) - - - .- - - - -
l.CCCCCC
133 160 136 140 54
137
2.ssssss
3.cscscs
127 183
42
:2 36
ii
;:
z;
4.ccsccs
127 170 35 149 70
3 9
5.sscssc
40 40 183 51 31
1 4 6
Rosemoun t
Year
Treatment
1984 1985
1 9 8 6
1987
1988
1989
-------- grain yield(bu. acre-l) - - - .- - - - -
l.CCCCCC
147
1 6 9
163
2 2
125
2. s s s s s s
3 9
2;
3.cscscs
156
1;:
4:
118
3 4
4.ccsccs
127
$5
40
1 6 9
7 0
4 0
5.sscssc
3 4
2 6
1 8 4
4 5
2 4
11
Waseca
Treatment
1 9 8 4
1985
1986 1987
1988
1989
- - - - - - - - grain yield(bu. acre-‘) - - - .. - - - -
l.CCCCCC
9 5
133
137
145
1 4 4
2.ssssss
3 0
2 5
3 9
4 1
29
3 9
3.cscscs
3 0
1 3 2
4 8
9 3
4 0
4.ccsccs
89
122
4 4
1 2 9
E
3 7
5.sscssc
3 2
2 7
133
46
1 9 4
Al1 locations combined
Year
Treatment
1984 1985
1986 1987
1988 1989
-------- grain yield(bu. acre-‘) - - - -. - - - -
l.CCCCCC
125
127
147
149
135
2. s s s s s s
3.cscscs
3 7
121
3 04
3 9
165
:::
78
94
37
4.ccsccs
1 1 4
1 2 9
4 0
1 4 9
27
3 8
5.sscssc
3 5
31
167
4 7
153
1 8
Table 5.
Average returns based on history of cropping systems (1984-1989)
location
locations
Treatments
Lamberton Wascea
Rosemount
combine4
- - - - - - - - return ($ acre-l year-l) - - - - - - - - -
cccccc
156 b
108 b
145 a
136 b
s s s s s s
14Oc
99 b
118 c
114 d
c s c s c s
159 b
95 b
147 a
134 bc
c c s c c s
156 b
91 b
123 bc
123 c
s s c s s c
188 a
155 a
138 ab
160 a
C.V. (%)
6.5
18.0
8 . 4
10.4
-
-
*
Within each column means with the same letter are not significantly different at
the 0.05 probability level according to Duncan’s Multiple Range Test.
1 9
Table 6. Returxoperating cost ratios of the fïve cropping systems.
Treatments
Lamberton
Rosemount
Waseca
- - - - - - _ ratio* _ _ _ _ _ _ _ _ ,_ - -
1 - c c c c c c
-;.06
0.57
0.88
2 - ssssss
1.87
1.03
1.50
3 - c s c s c s
1.37
0.63
1.20
4 - c c s c c s
1.28
0.61
0.89
5 - s s c s s c
1.82
1.29
1.29
* ratio =
return ($/acre/yearI
operating cost ($/acre/year)
Table 7. Average annual prices paid to Minnesota fax-mers.
l?rice of
SoybeanCorn
Year
C O
Soybean
mice ratio
_ _ ?$ bushel-1 _ _ _
1975
2.50
5.02
2.01
1 9 7 6
2.03
7.22
3.55
1977
1.90
5.90
3.11
1978
2.08
6.52
3.13
1 9 7 9
2.26
2.65
1 9 8 0
2.85
7”~~
2.54
1981
2.33
5:77
2.48
1 9 8 2
2.63
5.81
2.21
1983
3.05
7.64
2.50
1 9 8 4
2.47
5.60
2.27
1985
2.05
4.98
2.43
1 9 8 6
1.46
4.72
3.29
1987
1.55
5.70
3.68
1988
2.35
5.50
2.34
1989
2.40
5.80
2.42
Mean
2.70
Std. Dev.
0.50
L Q W
2.01
High
3.68
Source: Minnesota agricultwal statistics
(prices do not include government support).
2 1
Table 8. Sensitivity analysis: returns above operating costs ($/acre/year) for selected
com prices and soybeaxcorn (S:C) ratios at Larnberton, Rosemount, and Waseca.
Com mice = $1,46/bu (10~1
Lamberton
Rosemounl
l!!!as2
S:C ratio
S:C ratio
-S:C.r:atio..
Treatments
2.2
2.7
3.2
2.2
2.7
3.2
2.2
2.7
3.2
-------__-----------
$ acre-l yem-l_ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ I _ _ _ _ . _ _
1. c c c c c c
37b*
37d
37d
24bc
24b
24 d
-. 8 c
“’ 8 c
.’ 8 c
2. ssssss
41 b
69 b
97a
30 ab
55 a
75 a
12 b
:36 b
61 a
3. cscscs
45 b
5oc
76c
36 a
49a
62b
-,4bc
lOc
25 b
4. ccsccs
43 b
6Obc
61~
16 c
26b
36~
-’ 8 c
3 c
13bc
5. s s c s s c
65 a
85a
105 a
36 a
51 a
67 b
39 a
:58 a
78 a
C.V. (%)
14
11
9
24
18
14
:100
"70
55
Corn txice = $2,4O/bu (mediuml
Lamberton
Rosemount
waseca
S:C ratio
S:C ratio
-$:C.e_
Treatments
2.2
2.7
3.2
2.2
2.7
3.2
2.2
2.7
3.2
~.----_-
___________------___ $acre-l ye*-l_____ I _____ -__ ___.. _____. __
1 . c c c c c c
156b* 1 5 6 b 1 5 6 d
145a 145ab 145b
1108 a
i108b ‘108~
2. ssssss
1'21~
167b
213b
101 c
141 ab 189a
81 b
1120 b
‘162 b
3. cscscs
148b 173’b 198b
138 a
160a
181 a
8 4 b itO8b 1131bc
4. ccsccs
1 4 9 b 164’b 179~
116bc 132b 148b
8 4 b 1:OOb .117c
5. sscssc
173a
203,a
238a
127ab 152a
178 a
1.41 a
IL'73 a
206 a
C.V. (%)
7
6
6
9
8
7
18
18
19
Com mice = $3.05/bu (hiph)
Lamberton
Rosemount
wctseca
S:C ratio
S:C ratio
-$:Cratio..
Treatments
2.2
2.7
3.2
2.2
2.7
3.2
2.2
2.7
3.2
-------------w----me$ acre-l ye=-l _ _ _ _ _ I _ _ _ _ _ _ _ _ _ _ _ _. _ _ _ ._ _ _ _ _
1. c c c c c c
239 ab* 239 ‘b
239 c
229 a
229 ab 229 b
1188 a
1188 b
l88 b
2. ssssss
176~
239'b
294 b
149d
201 c
253 a
1129b
K80b
231b
3. cscscs
219b
25lb 284b
209ab 236a
264a
1147 b
1175 b
205 b
4. ccsccs
2 2 3 b 2 4 1 b 260~
185~ 206b 2 2 6 b
1145 b 168 b ‘189 b
5. s s c s s c
247a
289~1
330a
191 bc 223 abc 256 a
Z!ll a
253 a
294 a
C.V. (%)
6
6
5
7
7
6
14
14
15
* within each column means with the same letter are not significantly different at the 0.05 probabilky
level according to Duncan’s multiple range test.
22
Table 9. Ranking of retums for fïve cropping systenw at Lamberton, Waseca, and Rose-
mount for different combinations of com prices, and com:soybean price ratios.
Lamberton
Com Price
--.--_-
($1.46lbuI
Low
Med($2.40/bu)
1lip-h ($3.05/bul
Soybea x0 atio
Sovbea .com ratio
S lybea xom rab
2.2
2n:7 m 3.2
2.2
2n:7
3.2
2’2
z.7
3.2
Treatment
-.-.-
- - - - - - - - - - - - - - - - - - - - r&&g* - - - - - - _ - _. I _ - - ,.. _- - - .- -
1 - c c c c c c
5 5 5 2
5
2!
4;
,c-
2 - s s s s s s
4 3 2 5
3
2
5;
4
IL;
3 - c s c s c s
2 4
2
4 2
13
4 ‘- c c s c c s
3 4
:
3
4
:
3
-1
3
4
5 - s s c s s c
1 1 1 1
1
1
1
1
1.
Rosemount
C o m P r i c e --_--_-
Low ($1.46/bul
Med($2.40/bu)
High ($3.05/buj
Sovbeanxom ratio
Sovbeaxcom ratio
~ovbeaxcom rat&
2.2
2.7
3.2
2.2
2.7
3.2
2.2
2.7
3.2
- - ra&ipg*
- - - - - - - - _. - - - - . - - - - <_ -
I!,
1
2 _- cccccc
ssssss
------;----;-----i
3 3 3 4
4
51
1zi
‘V
5
<-
‘”
.;;
3 - c s c s c s
2
-1
1
1
4 - c c s c c s
: 4 4
3
:
4
ii
4
5
5 - s s c s s c
2 2 2
2
3
2;
3
‘3
Waseca
Com Price
--~-_-
Low ($1.46/bu)
Med($2.40/bu)
High ($J.OS/bu~
Soybeanxom ratio
Sovbean:com ratio
Sovbeanxom ratio
2.2
2.7
3.2
2.2
2.7
3.2
2.2
2.7
3.2
Treatment
-
-
-
-
-
-
-0_________________- r&hg* - - - - - - - - _. - - - - . . - - . . - - -
1 - c c c c c c
5 2
4
5
2!
‘7
.!,
!5
2 - s s s s s s s
2 2
;
;
2
2
2;
3
1-
7
3 - c s c s c s
3 3 3
3
3
4
4
3
4 - c c s c c s
4 4 4 4
5
4
3
15
4
5 - s s c s s c
1 1 1 1
1
1
l
Ii
l
* ranking of 1 = the most profitable sequence; 5 = the least profitable sequence.
Appendix 1: Rates of inputs applied on plots at Lamberton, Rosemoun t, and Waseca
from. 1984 to 1989
Fertilizer (# per acre)
Herbicides (#peracre)
Insecticides (ozper 1100 ft 11
N* P K
lasso lorox basagran oil
furadan counter losban
LAMBERTON
1984
125 100 100
2.5
2 . 5
-
._
1985
125 100 100
2.5
1.5
-
._
1986
125 -
-
2.5
1.5
-
._
1987
125 -
-
3 . 0
1.5
-
._
1 .O
1988
125 100 100
2.5
1.5
-
._
1.0
1989
130-
-
3 . 0
1.5
-
R O S E M O U N T
1984
_
_
_
-
-
-
<_
1985
160 -
-
2 . 5
-
1.0
._
1 .O
1986
160 -
-
2.5
-
1.0
.-
1 .O
1987
180 -
-
2.5
-
1.0
2 . 0
1 .O
1988
170 -
-
-
-
-
2 . 0
1 .O
1989
160 -
-
2.5
-
1.0
2.0
W A S E C A
1984
163 -
-
3.5
1.5
-
2 . 0
1.0
1985
175 -
-
-
-
-
2 . 0
1.0
1986
175 -
-
3 . 0
1.5
-
2 . 0
1.0
1987
175 -
-
3.5
1.5
1.0
2 . 0
1.0
1988
163 -
-
3.5
1.5
-
2 . 0
1 .o
1989
163 -
-
3,5
1.5
1.0
2 . 0
* Nitrogen was applied only on plots planted to com.
2 4
Appendix 2: Soil ‘characteristics
Lamberton: Webster: fiie loamy. mixed.Typic Hanluquoll
-slope O-3%
-poorly drained soi1 on glacial moraines
-surface layer black granular or blocky, friable clay loam or loam 14 to 16 inches
thick
-subsurface layer very dark gray to olive gray, friable clay loam 19 to 21 inches
thick, certain few mottles
underlaying material strongly mottled, gray calcareous loam, substrats with, many
lime concretions, 32to37 inches thick
-available water capacity: 15.6 inches to 5 feet
-high organic mater: 67%
-moderately permeable
Waseca: Nicollet: fine loamv. mixed.Aauic Hanludoll
-slope: O-2%
-moderately well draïned soi1 on the uplands
-surface layer black to very dark grayish brown clay loam 8 to 16 inches thick
-subsurface dark grayish brown clay loam 2 5 to 35 inches thick
-underlaying material olive gray calcareous loam or clay loam
-avalaible water capacity: 9.5 inches to 5 feet
high organic mater: 6%
-moderately permeable
Rosemount: Waukegan: fine silt loam. mesic.Typic Hapludoll
-slope: 2-6%
-well drained soil
-surface layer black silt loam about 14 inches thick
-subsurface layer dark grayish brown silt loamabout 3 inches thick
-underlaying material dark brown sand about 4 inches thick
-avalaible capacity: 10.7 inches to 40 inches
-organic mater: 2-6%
-moderately permeable in uuper mantles and rapid in underlaying soif and bedrock
_-__._._
_-..___-..“-.+----.__1_1-I
_.___
-
_,._.
_-_,
----
____ ;z
-_____. ._-_
I-_.------. _,_ l-..-*.---..-.~
__-____
_-._-.-.. .-----
.-m---------
2 6
Appendix 3.1 Soi1 levels of extractable phosphorus and exchangeable potassium
as affected by trop history.
LAMBERTON
Crop to be plauted
C
S
S
C
S
No.of years of C out of previous 5
5
3
2
1
0
No.of yeasr of S out of previous 5
0
2
3
4
5
Soi1 P(lb.acre-1)
50
51
54
57
57
Soil K (lb.acre- 1)
263
277
330
310
330
ROSEMOUNT
Crop to be plauted
C
S
S
C
S
No.of years of C out of previous 5
5
3
2
1
0
No.of years of S out of previous 5
0
2
3
4
5
Soi1 P(lb.acre-1)
68
60
81
70
83
Soil K(lb.acre- 1)
257
268
276
L!79
316
WASECA
Crop to be plauted
C
S
S
C
S
No.of years of C out of previous 5
5
3
2
1
0
No.of years of S out of previous 5
0
2
3
4
5
Soi1 P(lb.acre-1)
69
88
76
79
88
Soil K(lb.acre-1)
388
397
406
409
411
ALL LOCATIONS COMBINED
Crop to be plauted
C
S
S
C
S
No.of years of C out of previous 5
5
4
3
1
0
No.of years of S out of previous 5
0
2
3
4
5
Soil P(lb.acre-1)
62
66
70
69
76
Soil K(lb.acre- 1)
303
314
337
322
352
Imnortant noin&
1.
Com monocullture reduced soi1 P and K levels as compared to soybean monoculture.
2 .
lhere was a trend of increasing soi1 P and K with decreasing frequency of years of
com during the last 5 years.
27
Appendix 3.2: Com (C) and soybean (S) leaf concentration of P and K: at flowering
(com=silking, soybean=R3) in 1989.
Lamberton
Rosemount
Waseca,
P
K
P
K
P
K
s . . . . . . . . . . . . . . . . . . . . . . . g.kg-l,........,...... . . . . . . . .
Continuous C
3 . 0
17.8
3.5 12.9
2 . 9
17”O
C after 2 of
years
S
2 . 9
18.0
3.5 12.9
2 . 8
17.0
Continuous S
4 . 5
18.9
6.5 21.8
6 . 0
2 1 . 9
S after 1 of
year
C
4 . 6
19.9
6.7 21.8
5.7
21..9
S after 2 of
years
C
4 . 5
18.5
7.0 23.0
6.1.
2 2 . 7
Important point
Com and soybean leaf concentration of P and K was not affected by the rotation history.
28
Anuendix 3.3: Leaf concentration of Ca, Mg, Fe, Mn, Zn, CU, and B in com (silking
stage) and soybean (R3 stage) plants in 1989.
LAMBERTON
Ca Mg
Fe Mn
zl CU
l3
. ..g.g-l...
. . . . . . ...” . . . . . . .
IXtg.g-l................
Continuous C
5.6 4.7
124.5
5 5 . 0
23.5
9 . 5
6.3
C after 2 years of S
5.2 4.5
133.0
5 5 . 0
2 4 . 0
10.3
‘6.6
Continuous S
8.4 4.4
9 2 . 3
4 1 . 5
32.5
7.0
3 7 . 0
S after 1 year of C
8.3 4.2
9 0 . 5 4 4 . 5
3 2 . 5
7.0
3 6 . 0
S after 2 years of C
8.5 4.4
9 3 . 0
4 1 . 5
3 2 . 0
7.0
37.5
ROSEMOUNT
Continuous C
6.7 8.1
154.0
5 4 . 0
2 2 . 0
11.0
6 . 0
C after 2 years of S
6.8 8.3
162.0
5 7 . 0
2 3 . 0
10,5
5.5
Continuous S
10.2 5.3
9 8 . 3
5 9 . 0
42.0
40.0
S after 1 year of C
9.2 5.1
9 5 . 8
57.0
4 3 . 3
;:5
3 9 . 0
S after 2 years of C
9.3 5.1
9 5 . 0
5 4 . 0
4 5 . 5
1010
38.5
WASECA
Continuous C
4.9 4.1
150.0
2 7 . 0
2 5 . 0
8 . 0
5 . 0
C after 2 years of S
5.0 4.4
128.5
2 5 . 5
22.5
8.,8
s.5
Continuous S
10.3 4.9
101.0
44.0
41.5
4 7 . 5
S after 1 year of C
10.3 4.7
101.5
4 7 . 0
4 2 . 5
9*3
4 6 . 5
S after 2 years of C
10.0 4.5
9 6 . 5
4 6 . 3
4 1 . 5
9:5
47.:5
Imnortant noints
1 .
Com and soybean concentration of Ca, Mg, Fe, Mn, Zn, CU., and B was not affected
by the rotation history.
2 .
Ca and B concentration was greater in soybean leaves than in com leaves.
3 .
Fe concentration was higher in com leaves than in soybean leaves.