Effects of crop rotation and irrigation on soybean and wheat doublecropping on clay soil: an economic analysis

22 Pages·1994·0.99 MB·English

by  Wesley, R.A

Historic, archived document
Do not assume content reflects current
scientific knowledge, policies, or practices.
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United States Crop
Effects of
Department of
Agriculture
Agricultural Rotation and Irrigation
Research
Service
ARS-119 on Soybean and Wheat
December 1994
Doublecropping on
Clay
Soil
, 6
p ^
An Economic Analysis
Abstract
Wesley, R.A., L.G. Heatherly, C.D. Elmore, and S.R. Acknowledgments
Spurlock. 1994. Effects ofCrop Rotation and Irrigation The authors sincerely appreciate the assistance ofRay
on Soybean and Wheat Doublecropping on Clay Soil: Adams and John Black in conducting the field experi-
An Economic Analysis. U.S. Department ofAgricul- ments and preparing the data for economic analysis.
ture, Agricultural Research Service, ARS-119, 20 pp.
While supplies last, single copies ofthis publication
Field experiments were conducted from 1984 to 1991 to may be obtained at no cost from USDA-ARS, Applica-
determine and compare the yields and economic returns tion and Production Technology Research Unit, P.O.
ofsoybean Glycine max (L.)] monocrops, continuous Box 36, Stoneville, MS 38776.
[
wheat [Triticum aestivum (L.)]-soybean doublecrops,
and 2-year rotations ofcom [Zea mays (L.)]/wheat- Copies ofthis publication may be purchased from the
soybean and sorghum [Sorghum bicolor(L.) Moench]/ National Technical Information Service, 5285 Port
VA
wheat-soybean in irrigated and nonirrigated environ- Royal Road, Springfield, 22161.
ments on Tunica clay (clayey over loamy, montmorillo-
nitic, nonacid, thermic Vertic Haplaquept). Yields,
production records, and commodity prices were used to The UnitedStates Department ofAgriculture (USDA)
calculate annual net returns above specified costs for prohibits discrimination in itsprograms on the basis of
each cropping system. In the irrigated study, the highest race, color, national origin, sex, religion, age, disabil-
overall net returns per acre were produced by the corn/ ity, political beliefs, andmarital orfamilial status. (Not
wheat-soybean ($136.29) and the wheat-soybean allprohibited bases apply to allprograms.) Persons
doublecrop ($123.47) systems, whereas the lowest with disabilities who require alternative meansfor
overall net returns per acre were from soybean communication ofprogram information (Braille, large
monocrops ($52.85). In the nonirrigated study, the print, audiotape, etc.) should contact the USDA Office
highest overall net returns per acre were from the ofCommunications at [phone] (voice) or(202)
sorghum/wheat-soybean rotation ($63.65) and the 720-7808 (TDD).
wheat-soybean doublecrops ($47.79). The lowest
overall net returns per acre were from the nonirrigated Tofile a complaint, write the Secretary ofAgriculture,
com/wheat-soybean rotation ($15.47). Supplemental U.S. Department ofAgriculture, Washington, DC
irrigation ofthe summercrops increased the overall net 20250, orcall [phone] (voice) or (202) 720-
returns per acre ofsoybean monocrops ($28.12), wheat- 1127 (TDD). USDA is an equal employment opportu-
soybean doublecrops ($75.68), com/wheat-soybean nity employer.
rotations ($120.82), and sorghum/wheat-soybean
rotations ($31.67). The average net returns per acre of
wheat were high for all cropping systems, whereas the Issued December 1994.
average net returns per acre ofnonirrigated soybean in
all cropping systems were not sufficient to cover land
rental charges.
Keywords: economic analysis, cropping system, yields,
crop rotation, irrigation, com, sorghum, soybean, wheat,
monocrop, doublecrop.
Contents
Materials and Methods 2
Agronomic materials and procedures 2
Determination of costs and returns 2
Results and Discussion 3
Effects of irrigation on crop yield 3
Economic returns in response to irrigation 3
Conclusions 6
References 6
Tables
1. Crop sequences for corn, sorghum, soybean, and wheat grown
near Stoneville, MS 8
2. Yields of corn, sorghum, soybean, and wheat grown in monocrop,
doublecrop, and rotational cropping systems over an 8-year period
on Tunica clay near Stoneville, MS 9
3. Seasonal average price plus deficiency payment received per
bushel of corn, sorghum, soybean, and wheat in Mississippi 10
4. Gross returns from corn, sorghum, soybean, and wheat grown in
monocrop, doublecrop, and rotational cropping systems over an
8-year period on Tunica clay near Stoneville, MS 11
5. Total specified costs of production of corn, sorghum, soybean,
and wheat grown in monocrop, doublecrop, and rotational cropping
systems over an 8-year period on Tunica clay near Stoneville, MS 12
6. Net returns above total specified costs for corn, sorghum, soybean,
and wheat from monocrop, doublecrop, and rotational cropping
systems over an 8-year period on Tunica clay near Stoneville, MS 13
7. Average variable costs and fixed expenses for monocrop,
doublecrop, and rotational cropping systems over an 8-year period
on Tunica clay near Stoneville, MS 14
iii

Effects of Crop Rotation and
Irrigation on Soybean and Wheat
Doublecropping on Clay Soil
Art Economic Analysis
R.A. Wesley, L.G. Heatherly, C.D. Elmore, and
S.R. Spurlock
Crop rotation, the growing ofdifferent crops in a researchers showed that profits from the I wheat-
regular sequence, is a process that increases crop yields soybean doublecrop systems were higher than profits
(Fahad et al. 1982, Baird and Benard 1984, Boquet et from the soybean monocrop when the wheat straw was
al. 1986, Young et al. 1986, and Dabney et al. 1988). burned before the soybean was planted as a no-till crop.
Crop rotations ofcom Zea mays (L.)J-wheat Triticum In a nonirrigated (NI) companion study, returns from
[ [
aestivum (L.)J-soybean [Glycine max (L.) Merr.], and wheat-soybean doublecrop systems in which the no-till
sorghum [Sorghum bicolor(L.) Moench]-wheat- soybeans were planted in standing orburned wheat
soybean not only enhance yields ofrotational crops but stubble were higherthan those from the soybean
also permit effective control ofjohnsongrass [Sorghum monocrop mainly because ofthe returns generated by
halepense (L.) Pers.] during the soybean sequence the wheat. In fact, returns ofthe NI soybean monocrop
(Litsinger and Moody 1976). Likewise, irrigation has were not sufficient to cover land rental charges.
been shown to consistently and significantly increase
soybean yields on clay soil regardless ofplanting date A study conducted on two Blackland Prairie soils in
or row spacings (Heatherly 1984, Heatherly 1988). Mississippi indicated that a wheat-soybean doublecrop
Recent research indicated that irrigation increased com system was more profitable and also more soil conserv-
yields 63 percent, whereas sorghum yields were ing than soybean monocrop systems (Hairston et al.
increased only 1 percent (Heatherly et al. 1990). 1984). Sanford et al. (1986) conducted aNI study to
1
evaluate monocrop systems ofcom, soybean, sorghum,
The adoption and continued use ofrotational cropping wheat, and sunflower [Helianthus annuus (L.)] and
systems and the decision ofwhether or not to irrigate doublecrop systems ofwheat rotated with com, soy-
are partially dependent on economic relationships. An bean, sorghum, and sunflower. The two cropping
economic analysis has shown that properly timed systems with the highest net return were the com
irrigation ofa soybean monocrop system on Dubbs silt monocrop followed by the wheat-soybean doublecrop.
loam (Typic Hapludalf, fine-silty, mixed, thermic) in Crabtree et al. (1986) compared yields and net returns
the Mississippi Valley can result in increased returns to ofmonocrops and doublecrops ofwheat and sorghum
help offset overhead from land rental, management, in which the wheat was not irrigated and the sorghum
and general farm costs (Salassi et al. 1984). In an was either not irrigated or irrigated (sprinkler). NI
irrigated (I) study on Tunica clay (clayey over loamy, monocrops ofwheat produced the highest net return,
montmorillonitic, nonacid, thermic Vertic Haplaquept) but returns ofNI monocrops ofsorghum were nearly
in the Mississippi Valley, Wesley and Cooke (1988) equal to those ofwheat. In another study that involved
showed that profits were greater from a soybean monocrops and doublecrops ofwheat and soybean,
monocrop system than from wheat-soybean doublecrop Crabtree et al. (1987) indicated that highest net returns
systems in which soybean was planted as a no-till crop were produced by NI doublecrops ofwheat and NI
in standing wheat stubble. However, these same doublecrops ofno-till soybean. Sprinkler irrigation
increased the yield ofsoybean monocrops and
doublecrops 9.5 and 7.8 bushels/acre, respectively.
Wesley is an agricultural engineer and Elmore is a plant However, given these yields, irrigation of soybean was
physiologist, U.S. Department of Agriculture, Agricultural
Research Service, Application and Production Technology not economically feasible.
Research Unit, P.O. Box 36, Stoneville, MS 38776. Heatherly
is an agronomist, U.S. Department of Agriculture, Agricultural In the lower Mississippi River Valley, clay soils
BReosxe3a4r3c,hSSteornevviiclel,e,SoMySbe3a8n77P6r.odSupcutriloonckReisseaanracghriUcnuiltt,urPa.lO. occupy almost half(9.6 million acres) ofthe land area.
economist, Agricultural Economics Department, Mississippi Most ofthis acreage is planted to NI soybean mono-
State University, Mississippi State, MS 39762. crops. Soybean yields from this system ofproduction
1
.
have been consistently low and only marginally Recommended management practices were used to
profitable. The objective ofthis study was to determine schedule cultural, weed control, and irrigation inputs to
the feasibility ofusing irrigation and crop rotations to each cropping system. All plots were mechanically
enhance yields and economic returns on these clay cultivated for weed control as needed during the early
soils. In this study, yields and economic returns offour part ofthe growing season. Fertilizers and pesticides
cropping systems grown in I and NI environments were were applied as needed for prevailing conditions. All N
compared for this purpose. The cropping systems applications to com and sorghum were applied beside
included a soybean monocrop, wheat-soybean each row as urea-NH N0 solution. N applications to
4 3
doublecrop, and two-year rotations ofcom/wheat- wheat consisted ofgranular urea-[CO(NH,)J broadcast
soybean and sorghum/wheat-soybean. in the spring. Each crop in each replicate was irrigated
separately by controlling gates and nozzles. Irrigation
ofcom began at tassel emergence and ended at near-
Materials and Methods dent stage. Irrigation ofsorghum began at the boot
stage and ended at the hard-dough stage. Soybean
Agronomic Materials and Procedures irrigation started when the first bloom appeared and
The study was conducted for 8 years (1984-1991) on a ended at the full-seed stage. Irrigation water was
Tunica clay near Stoneville, MS. The soil has a high applied only during each crop’s reproductive period
percentage ofclay (50-60 percent), poor internal and only when the soil water potential (as determined
drainage, and high water-holding capacity. Soil pH by tensiometers located at the 12-inch soil depth in
ranged from 6.0 to 6.5, percentage organic matter three replicates) averaged between -50 and -70
ranged from 0.89 to 2.41, and P and K levels were centibars. Previous research with soybean on clay soil
within ranges recommended by the Mississippi Coop- showed that a greater yield response was obtained
erative Extension Service. Tw—o adjacent areas were when the need for irrigation was measured at this
designated for the experiment one for irrigated tensiometer depth rather than at a deeper depth
production and one for nonirrigated production. Plots (Heatherly 1984). All plots were machine-harvested at
ofeach crop were 60 feet wide by 100 feet long. crop maturity. Yields ofcorn and sorghum were
adjusted to 15.5 and 14.0 percent seed moisture (dry
The study included four cropping systems (treatments). basis), respectively, whereas yields ofsoybean and
Treatments were continuous soybean monocrop, wheat were adjusted to 13.0 percent seed moisture (dry
continuous wheat-soybean doublecrop, and 2-year
basis).
rotations ofcom/wheat-soybean and sorghum/wheat-
soybean. Treatments were arranged in a randomized The power equipment included one 90- to 100-draw-
complete block design with four replicates in both I and bar-horsepower (DBHP) tractor, one 100- to 115-
NI experiments. Data obtained included eight cycles of DBHP tractor, one 115- to 150-DBHP tractor, and one
the soybean monocrop and wheat-soybean doublecrop self-propelled combine having a 20-foot header width,
and four cycles ofthe com/wheat-soybean rotation and an auxiliary header, and reel equipment for harvesting
sorghum/wheat-soybean rotation. Crop sequences for com. The other equipment included a heavy disk, disk
each cropping system are presented in table 1 harrow, field cultivator, no-till planter, cultipacker,
grain drill, cultivator, liquid-fertilizer applicator, stalk
The soybean monocrops were planted in a prepared shredder, spin spreader, and tractor-mounted sprayer.
seedbed, whereas soybeans in the wheat-soybean
doublecrop and in the com/wheat-soybean and sor- Determination of Costs and Returns
ghum/wheat-soybean rotations were planted as no-till Crop enterprise budgets were developed annually for
crops in burned wheat stubble. All wheat was drill- each cycle ofeach cropping system in the I and NI
seeded in 7-inch rows, whereas corn, sorghum, and environments. The costs ofspecific inputs, such as
soybean were planted in 40-inch rows near the opti- fertilizers, pesticides, and water were accounted for in
mum planting dates. Com and sorghum were planted each experiment. Crop prices used in the budgets were
on beds that had been formed the previous fall.
2
the seasonal average prices received for the year as Effect of Irrigation on Crop Yield
reported by the Mississippi Agricultural Statistics Wheat yields from all cropping systems in the I and NI
Service (1984-91) and adjusted for deficiency pay- environments were similar each year (table 2). Overthe
ments per unit ofcom, sorghum, and wheat. Variable test period, the average yields ofwheat from all crop-
costs were the actual prices paid by farmers each year ping systems ranged from 38.2 to 48.8 bushels/acre.
to produce a crop and included the cost ofherbicides,
seed, labor, fuel, equipment repairs and maintenance, Irrigation increased the average yield ofsoybean in all
and interest on operating capital. Fixed costs included cropping systems. In the soybean monocrop, wheat-
costs oftractors, self-propelled equipment, implements, soybean doublecrop, com/wheat-soybean rotation, and
and the irrigation system. Total specified costs included sorghum/wheat-soybean rotation, irrigation increased
both variable and fixed costs. Net returns per acre were soybean yields 91 percent (41.1 vs. 21.5 bushels/acre),
calculated annually as the difference between gross 202 percent (32.6 vs. 10.8 bushels/acre), 92 percent
income and total specified costs. Average net returns (38.2 vs. 19.9 bushels/acre), and 69 percent (37.3 vs.
were calculated foreach crop as the mean ofthe annual 22.1 bushels/acre), respectively. All wheat and soybean
net returns overthe study period. Overall net returns yields for crop years 1984-89 are discussed in detail in
reflected the average net returns to each cropping an earlier report (Wesley et al. 1991).
system overthe 8-yearperiod. In the budgets no
charges were included for land, management, or Yields ofcorn from the I environment ranged from
overhead. Performance rates on all field operations 100.0 to 156.2 bushels/acre (table 2). However, yields
were based on using eight-row equipment with associ- ofcom from the NI environment were highly variable
ated power units. because ofthe occurrence ofsevere moisture stress in
some years. In 1986 yields ofNI com averaged 89.2
Irrigation costs were based on a quarter-mile center bushels/acre because ofnear-adequate soil moisture,
pivot system capable ofirrigating 130 acres from 1 but in 1988 the NI com emerged afterplanting but died
pivot point. Investment costs included the cost ofan before harvest due to severe moisture stress.
engine, well, pump, gearhead, generator, fuel tank and
fuel lines, and the pivot system. Total fixed costs Sorghum yields from the I experiments of 1984, 1988,
consisted ofannual depreciation, interest on invest- and 1990 averaged 1 16.4 bushels/acre; however,
ment, and insurance. Annual depreciation was calcu- because oflow yields in 1986 caused by severe infesta-
lated using the straight-line method with zero salvage tions ofsorghum midge [Contarinia sorghicola
value. Annual interest charges were based on one-half (Coquillett)] the average yield ofI sorghum for the 4
ofthe original investment times a nominal interest rate years was only 103.3 bushels/acre. Yields ofsorghum
for each year ofthe study. Insurance was estimated at 1 from the NI experiment were variable. In 1984 and
percent ofthe original investment. Operating or direct 1990, yields averaged 84.0 and 86.1 bushels/acre,
costs included fuel, oil, labor, and engine repair. Fuel respectively, and were typical ofsorghum yields in the
requirements were determined from engineering area. However, because ofsevere midge infestation in
formulas (Spurlock et al. 1987). 1986 and insufficient soil moisture for planting in
1988, yield from the NI experiment averaged only 58.2
bushels/acre.
Results and Discussion
Economic Returns in Response to Irrigation
Yields, commodity prices, gross returns, total specified Gross returns peracre (table 4) were calculated as the
costs, and net returns above total specified costs for product ofeach respective crop yield (table 2) and
each cropping system in the I and NI environments are commodity price (table 3). In 1988, when severe
presented in tables 2-6. Variable and fixed costs drought prevented the planting and development ofall
associated with each cropping system are shown in summercrops in the NI environment, gross returns for
table 7. the NI crops were zero and therefore decreased the
average gross returns per acre over the 8-year period.
3
The average specified costs per acre (table 5) for wheat whereas the lowest net returns were from the soybean
grown in the continuous wheat-soybean doublecrop monocrop ($52.85/acre).
system in I and NI environments were virtually identi-
cal ($85.27/acre and $84.10/acre, respectively) and In the NI study the highest overall net returns were
averaged $18.00/acre lowerthan those for wheat grown from the sorghum/wheat-soybean system ($63.65/acre)
in com and sorghum rotations. The higheraverage followed by the wheat-soybean doublecrop system
specified costs for wheat in the com and sorghum ($47.79/acre). The NI soybean monocrop system
rotations were a direct result ofthe additional tillage produced overall net returns of$24.73/acre, whereas
required to prepare a seedbed in the com and sorghum the lowest overall net returns were produced by the NI
residue and the additional N application needed in the com/wheat-soybean system ($15.47/acre). These data
fall to wheat following the com and sorghum crops. indicate that overall net returns from the NI sorghum/
wheat-soybean system and the NI wheat-soybean
In the I cropping systems, the average specified cost of doublecrop system were moderately higher than those
soybean was highest for the monocrop system from the NI soybean monocrop and considerably
($192.85/acre), whereas the average specified costs of higher than those from the NI com/wheat-soybean
soybean in the doublecrop system and in the rotations system. Also, the overall net returns from the NI
ranged from $165.59/acre to $170.89/acre. The higher sorghum/wheat-soybean system and the NI wheat-
specified costs for soybean in the monocrop system soybean doublecrop system were comparable to the
were due to the tillage required to prepare the seedbed, overall net returns from the I soybean monocrop.
whereas in all othercropping systems soybeans were
planted as no-till crops in burned wheat stubble. In the Examination ofthe net returns by crop within each
NI cropping systems, the average specified costs for cropping system indicates that irrigation increased the
soybean were highest in the com and sorghum rotation annual net returns ofthe soybean monocrops in all
systems ($105.93/acre and $105.47/acre, respectively). years except 1985, 1989, and 1991. In 1985 irrigation
The lower specified costs for NI soybean in the increased seed yield 14.3 bushels/acre (table 2);
monocrop ($99.05/acre) and doublecrop ($87.86/acre) however, the resulting increase in gross income
systems included the near-zero costs ofproduction for ($74.36/acre, table 4) was not sufficient to cover the
those systems in 1988. additional production inputs such as the cost ofirriga-
tion. Irrigation costs could have been reduced ifa less
The average specified costs for I and NI com were expensive surface irrigation method was used (see
$245.91/acre and $159.62/acre, respectively. Spurlock et al. 1987 for alternative irrigation methods).
In 1989 rainfall was near adequate; however, apparent
The difference between the specified costs ofI sor- waterdeficits occurred on several occasions. The
ghum ($222.53/acre) and NI sorghum ($120.67/acre) is soybean monocrop was irrigated four times because of
not typical; minimum production inputs were used in these deficits, but the I soybean produced 2.8 bushels/
the NI study in 1988 because the extreme drought acre less than the NI soybean (table 2). The reduced
prevented planting ofthe crop. However, in 1984, yield may have been due to the fact that a significant
1986, and 1990, the average specified costs ofI sor- amount ofrain was received after each irrigation. The
ghum still averaged $64.65/acre higher than NI sor- additional water apparently saturated the soil profile
ghum. and adversely affected yields. The lower gross return
plus the cost ofoverhead irrigation reduced the net
In the I study, the overall net returns (table 6) were return ofthe I soybean monocrop $88.33/acre below
highest from the com/wheat-soybean system ($136.29/ that ofthe NI soybean monocrop (table 6). In 1991
acre) followed by the wheat-soybean doublecrop waterdeficits occurred during the June-August period.
system ($123.47/acre). The overall net returns from the Because ofthese deficits, the soybean monocrop in the
sorghum/wheat-soybean system averaged $95.32/acre, I study was irrigated eight times. However, significant
rainfall was received after six ofthe irrigations. As in
4