Double-cropped Wheat Research Articles

Interactions of traffic and tillage applied to cotton on N movement below the root zone of a subsequent wheat crop

Although research has demonstrated the negative impact of traffic-induced soil compaction on crop productivity, knowledge is lacking regarding the interactive effects of equipment traffic and tillage systems, especially in regards to N management in conservationtilled multiple-cropping systems. The objective of this study was to examine the interaction of traffic and tillage systems applied to cotton ( Gossypium hirsutum L.) on N utilization and movement below the root zone of subsequent double-cropped wheat ( Triticum aestivum L.). A field study was initiated in 1987 on a thermic Typic Hapludult soil complex, utilizing a wide-frame tractive vehicle (WFTV) that allows for 6.1-m wide, untrafficked research plots to double-crop cotton with wheat. The experimental design was a split-plot with three replications. Main plots were: (1) conventional traffic (simulated with tractor); (2) no traffic (WFTV only). Subplots were tillage systems for cotton: (1) complete surface tillage without subsoiling (surface); (2) complete surface tillage and annual in-row subsoiling to 40-cm depth (subsoil); (3) complete surface tillage with once-only complete disruption of the tillage pan by subsoiling to a 50-cm depth on 25-cm centers in 1987 (complete); (4) strip-till where cotton was planted with in-row subsoiling into wheat residue. All tillage treatments were applied to the cotton and residual effects were observed in the wheat. In 1990–1991, fertilizer applications were made to wheat as 15N-labeled NH 4NO 3, and soil solution samples were collected (90-cm depth). While previous cotton tillage had no significant effect on wheat yields, traffic reduced wheat yields from 3427 to 2981 kg ha −1 in 1990. With no traffic, total fertilizer N recovery in the plant-soil system was increased by 20 and 10% in 1990 and 1991, respectively. The strip-till tillage treatment increased total fertilizer N recovery in wheat by 20% compared with other tillage systems in 1990. Surface tillage without subsoiling for cotton increased NO 3-N concentration below the root zone of wheat (90-cm depth) in both years. The data indicate that the tillage/traffic management system used for production of one crop in a doublecropping system was a major factor in reducing N losses and increasing fertilizer N recovery in the plant-soil system of the succeeding crop.

Cow weights and reproduction on native rangeland and native rangeland-complementary forage systems1

Replicated cow herds of 15 Angus x Hereford (AH) and 15 Brahman x Hereford (BH) F1 cows each were placed on native rangeland (NR) or native rangeland-complementary forage (NRCF) systems. The NR was 8.1 ha of sagebrush-mixed prairie per cow-calf unit and the NRCF used the same mixed prairie complemented by .4 ha of double-cropped winter wheat and summer annual forage replacing about 30% of the mixed prairie for each cow unit. Calving seasons, spring for NR and fall for NRCF, were selected to complement the respective forage systems. Cow weights, reproductive performance, and population demographics were measured through seven calf crops to investigate their relationship to forage systems and cow breed types. Seasonal average cow weights increased from 484 +/- 7 (SE) kg during calf crop 1 to a peak weight of 568 +/- 8 kg at calf crop 5. Average weight of AH cows was 514 +/- 3 kg, compared with 539 +/- 3 kg for the BH cows (P < .01). Angus x Hereford and BH cows were 38 and 44 kg heavier, respectively, on the NRCF system than on the NR system. The average percentage of reproduction for AH cows was 90 +/- 2%, compared with 87 +/- 2% for the BH cows (P < .13). Both breeds had approximately 87 (AH) to 89% (BH) reproductive rate on the NR system. In contrast, AH cows had 94 +/- 2% reproduction on the NRCF system, compared with 84 +/- 2% for the BH cows.(ABSTRACT TRUNCATED AT 250 WORDS)

Reduced chemical input cropping systems in the southeastern United States. I. Effect of rotations, green manure crops and nitrogen fertilizer on crop yields

AbstractInterest in reducing purchased chemical inputs to reduce production costs and avoid possible environmental damage prompted this 7-year study. Two management systems, current management practices (CMP) and reduced chemical inputs (RCI), were evaluated for four crop sequences from 1985 through 1992: continuous grain sorghum; continuous corn; a 2-year rotation of corn and double-cropped winter wheat and soybean; and a 4-year rotation of corn, winter wheat/soybean, corn, and red clover hay (changed in 1989 to a 3-year rotation of corn, red clover hay, and wheat/soybean). No-till planting and recommended rates of fertilizer and pesticides were used in the CMP system. In the RCI system, N was supplied by a crimson clover green manure crop or the red clover in the rotation. Weed control was by chisel plowing, disking, and cultivation.Crimson clover top growth accumulated from 70 to 180 kgN/ha, red clover from 77 to 130 kg N/ha. Rotating crops increased corn yield with CMP but not with RCI. lndry years, corn yields were low (less than 3000 kg/ha), corn did not respond to fertilizer N, and yields generally were higher with CMP than with RCI. With adequate rain, yield of all RCI treatments were the same as yield in CMP continuous corn receiving no fertilizer N. Johnsongrass competition was the main reason for low yields in the RCI treatments. Soybean yields were higher with CMP in 4 years and higher with RCI one year. Wheat and grain sorghum yields were higher with CMP than with RCI. A dramatic decline in johnsongrass in sorghum was noted in 1989, and several plots remained relatively free of johnsongrass through 1992.Management decisions made during the experiment included the degree of input reduction in RCI; whether to either end or modify unproductive treatments; whether to use newly available varieties and pesticides; whether to suspend the experiment to eliminate johnsongrass; and how to add new treatments while retaining the original treatments.

Potassium Fertilization of Doublecropped Wheat and Soybeans under Two Tillage Systems

Because the yield response to K in a wheat (Triticum aestivum L.)-soybean [Glycine max (L.) Merr.] rotation on Atlantic Coastal Plain soils may be influenced by tillage type and K application timing, a study was conducted between 1986 and 1988 on a Bojac loamy sand (coarse-loamy, mixed, thermic Typic Hapludult) to investigate the effects of tillage, K rate, and K application timing on soil and plant K and crop yields. The experimental design was a split plot, with tillage as the main plot factor and K rate × K application timing as the subplot factor. Tillage treatments were conventional tillage (CT) and no-till (NT). Potassium fertilizer (KC1) rates of 0, 36, and 72 lb K/acre were applied (i) 100% prior to wheat planting; (ii) 50% prior to wheat planting, 50% at Zadoks 30 growth stage; and (iii) 50% prior to wheat planting, 50% prior to soybean planting. Wheat yields under continuous NT management declined from 84 bu/acre in 1987 to 53 bu/acre in 1988, while CT wheat yields remained constant at 76 bu/acre in 1987 and 75 bu/acre in 1988. No-till soybeans significantly outyielded CT soybeans by 48 to 33 bu/acre in 1987 and 61 to 46 bu/acre in 1988. Neither wheat nor soybeans responded to K rate or timing of application despite reductions in soil test K to levels diagnosed as insufficient. Leaching losses contributed significantly to declines in soil K, as crop removal accounted for only a portion of the “missing” K. Testing for K on Coastal Plain soils should involve subsoil sampling, since both wheat and soybeans appear capable of procuring considerable amounts of K from deeper than 12 to 18 in. within the profile.

Cropping Systems for Clay Soil: Crop Rotation and Irrigation Effects on Soybean and Wheat Doublecropping

(...) Field experiments were conducted from 1984 to 1989 to evaluate alternate cropping systems for a Tunica clay soil (clayey over loamy, montmorillonitic, nonacid, thermic Vertic Haplaquept) in the lower Mississippi River Valley. Specific objectives were to (i) determine the seed yield response of monocrop soybean and doublecrop soybean and wheat grown in rotation in irrigated and nonirrigated environments, and (ii) determine the increase in gross income for soybean due to irrigation. Seed yields of monocrop soybean averaged over the 6-yr test period exeeded yield from doublecrop soybean in the irrigated (41.3 vs. 32.5 bu/acre) and nonirrigated (18.0 vs. 9.2 bu/acre) environments, respectively. (...)

Water Use Efficiency of Double‐Cropped Wheat and Soybean

AbstractMany studies have demonstrated that double cropping wheat (Triticum aestivum L.) and soybean [Glycine max (L.) Merr.] allows for greater utilization of natural resources by intensifying cropping practices. A 3‐yr study was conducted on a Captina silt loam (finesilty, mixed, mesic, typic Fragiudult) to determine the water use efficiency (WUE) of winter wheat and to determine the effects of selected management practices on WUE of double‐cropped soybeans. The 3‐yr mean grain yield of wheat was 3170 kg ha−1 and the mean cumulative evapotranspiration (ET) after 1 April was 32.8 cm. This translated into an average WUE of 96.6 kg ha−1 cm−1 of water. Shortly after wheat harvest, the effect of irrigation, planting date, and stubble management on soybean water use and yield were determined. Irrigation significantly increased soybean grain yield in 2 of 3 yr. The 3‐yr yield mean was 2406 and 1704 kg ha−1 for irrigated and non‐irrigated soybean, respectively. When irrigation significantly increased grain yield, irrigated soybean had a highet WUE than non‐irrigated soybean. Planting date had a significant effect on soybean yield and WUE in only 1 of 3 yr and only when planting date was confounded with row‐spacing. Burning of wheat stubble produced significantly higher soybean yields only when herbicide interference by standing wheat stubble was observed. Stubble management had no effect on soybean ET or WUE. The 3‐yr mean WUE for the double cropped wheat and soybean system was 79.3 kg ha−1 cm−1 of water.

Effects of Wheat and Soybean Planting Date onHeterodera glycinesPopulation Dynamics and Soybean Yield with Conventional Tillage

The influence of winter wheat (Triticum aestivum) cover crop vs. winter fallow and of soybean (Glycine max) planting date on the populations dynamics of soybean cyst nematode (Heterodera glycines) (SCN) was determined during a 2-yr period. Numbers of SCN cysts, eggs, and second-stage juveniles were unaffected by wheat as opposed to winter fallow. Delay in soybean planting associated with double-cropping wheat, however, allowed for a significant decline in the numbers of SCN between early May and late June. Midseason densities of early May soybean plantings were greater than those of mid-June to late June plantings (.)

A Case Study of Timeliness in the Selection of Risk-Efficient Machinery Complements

Abstract The importance of timeliness is investigated in the selection of machinery complements for double-crop wheat and soybean production in the southeastern coastal plain. An intertemporal stochastic simulation model was developed to generate probability distributions that were evaluated with stochastic dominance analysis. This research investigated the importance of intertemporal production linkages and inadequate soil moisture on machinery selection. Failure to include these dimensions can result in erroneous machinery choices.

Weed Control in Soybean under Different Cropping and Tillage Systems

Studies were established in 1987 and 1988 near Brooksville and Poplarville, MS, to evaluate six weed-control systems in monocrop soybean [Glycine max (L.) Merr.] and doublecrop wheat (Triticum aestivum L.) ― soybean planted both with and without prior tillage. (...)

Herbicide Efficacy for Various Application Times in Doublecrop Wheat and Soybean

AbstractEffective weed management is essential in reduced tillage doublecrop wheat (Triticum aestivum L.) and soybean [Glycine max Merr.] production. Field experiments were conducted on a Hartsells fine sandy loam soil (fine loamy, silaceous, thermic Typic Hapludalfs) near Crossville, AL, from 1981 to 1983 to determine the influence of application time on herbicidal efficacy of oryzalin [4‐(dipropylamino)‐3,5‐dinitrobenzenesulfonamide], pendimethalin [N‐(1‐ethylpropyl)‐3,4‐dimethyl‐2,6‐dinitrobenzenamine], and oryzalin + 2,4‐D [(2,4‐dichlorophenoxy)acetic acid] for weed control. Herbicides were applied early preplant (EP) to fully tillered wheat, and preemergence (PRE) at soybean planting. Paraquat (1,1'‐dimethyl‐4,4'‐bipyridinium ion) was applied separately at 0.3 kg ha−1 at the time of PRE applications to ail plots that received other herbicide applications (EP or PRE) and alone as a check treatment. Early preplant treatments did not reduce wheat seed yields in 2 of 3 yr compared to the untreated control. Fall panicum (Panicum dichotomiflorum Michx.) and prickly sida (Sida spinosa L.) control were similar with EP and PRE applications of all herbicides. Fall panicum control ranged from 63 to 100%, and prickly sida control from 20 to 87%. Early preplant applications provided greater Pennsylvania smartweed (Polygonum pensylvanicum L.) control than PRE applications. Pennsylvania smartweed control was 5 to 70% greater with EP applications compared to PRE applications. Preemergence applications of oryzalin + 2,4‐D produced moderate (20%) soybean injury in 1982 and 1983. Soybean seed yields were similar with EP and PRE applications in 1981 and 1982; however, seed yields were from 26 to 103% greater with EP applications than PRE applications in 1983.

MONO- AND DOUBLE-CROPPED WHEAT AND SOYBEANS UNDER RAIN-FED AND IRRIGATED CONDITIONS1

In sufficient amounts and distribution of rainfall are often the major limiting factors to crop production in the southern Great Plains. This is especially true for summer crops, whether grown in mono- or double-cropping situations, for these factors have a significant impact on yields and profitability. This study was conducted at the Oklahoma Vegetable Research Station, Bixby, Oklahoma, from 1980–1984 on a Wynona silt loam soil (Cumulic Hapla-quolls) with 0–1% slope. The objectives were to compare yields and net economic returns of mono- and double-cropped wheat [Triticum aestivum (L.) EM. Thell] and soybeans [Glycine max (L.) Merr.], where all wheat was produced under rain-fed conditions and where mono- and double-cropped soybeans were produced under both rain-fed and irrigated conditions. Over the 5-year period, rain-fed monocropped wheat yielded an average of 3498, compared with 3008 and 2948 kg ha-1 for rain-fed, double-cropped wheat following irrigated and rain-fed double-cropped soybeans, respectively. Irrigated, conventionally tilled monocropped soybeans yielded an average of 2800 compared with 2162 kg ha-1 for rain-fed, conventionally tilled monocropped soybeans. Irrigated, no-till, double-cropped soybeans yielded an average of 2072 compared with 1546 kg ha-1 for rain-fed, no-till, double-cropped soybeans. Rain-fed double-cropped wheat and rain-fed, no-till, double-cropped soybeans produced the highest net economic return ($317 ha-1) of any of the five cropping systems. Net returns from rain-fed, double-cropped wheat and irrigated, no-till, double-cropped soybeans; rain-fed mono-cropped wheat; and rain-fed, conventionally tilled, monocropped soybeans were similar and ranged from $246, $238, and $233 ha-1, respectively. Irrigated, conventionally tilled, monocropped soybeans returned $183 ha-1. Irrigation increased the yields of mono- and double-cropped soybeans 638 and 526 kg ha-1, respectively. However, given these yields, the price of soybeans would have to increase from $0.25 kg-1 to $0.31 and $0.40 kg-1, respectively, for mono- and double-cropped soybeans before irrigation would become economically feasible.

The effect of four tillage systems on growth and yield of double-cropped soybeans and wheat

The effect of four tillage systems on growth and yield of double-cropped soybeans and wheat

DOUBLE AND MONOCROPPED WHEAT AND GRAIN SORGHUM UNDER DIFFERENT TILLAGE AND ROW SPACINGS

Water is often the most limiting factor in producing the crop following wheat in regions with adequate frost-free days to permit double-cropping. To more fully utilize climatic resources, land, and machinery after the harvest of wheat grain, we conducted a field study on a Wynona silt loam soil (Cumulic Haplaquolls) to analyze the effects of tillage and row spacings on soil water content and yields of monocropped (MC) and double-cropped (DC) wheat and grain sorghum under rain fed conditions. When planted at the same time and over a 4-year period, double-cropped wheat (DCW) yielded 2260, compared with 2890 kilograms per hectare for monocropped wheat (MCW). Due to drought, grain sorghum as the second crop failed to produce grain 1 (1978) out of 4 years. For the 3 years of successfully double-cropping grain sorghum (DC-GS), conventional tillage, double-cropped grain sorghum (CT-DCGS) in 50-centimeter rows yielded 4080, compared with 3810 kg/ha in 75-cm rows. No-tillage, double-cropped grain sorghum (NT-DCGS) in 50-cm rows yielded 3830 compared with 3590 kg/ha in 75-cm rows. When planted at the same time as the DC-GS, conventional tillage, monocropped grain sorghum (CT-MCGS) in 50-cm rows yielded 4150 compared to 3760 kg/ha in 75-cm rows. For the double-cropped treatments, water content in 120 cm of soil profile was not significantly affected during the grain sorghum growing period by tillage and row spacings; however, tillage and planting operations must be timely to prevent loss of water in the soil-seed environment when attempting to establish a stand for the double crop. For the 3 years of successful double-cropping, an average of only 12 percent of the precipitation that fell from mid-June (after wheat grain harvest) to early October was detected as stored water in the monocropped wheat plots. More grain production and more effective use of annual precipitation and soil water were achieved 3 out of 4 years when wheat and grain sorghum were double-cropped.

Double and Monocropped Wheat and Soybeans Under Different Tillage and Row Spacings1

AbstractIn wheat [Triticum aestivum (L.) Thell] producing regions with adequate frost‐free days to permit double‐cropping, water is often the most limiting factor in producing the second crop. To more fully utilize climatic resources and land after the harvest of wheat grain, a field study was conducted on a Wynona silty clay loam (Cumulic Haplaquolls) to analyze the effects of tillage and row spacings on soil water content and yields of monocropped (MC) and double‐cropped (DC) wheat and soybeans [Glycine max (L.) Merr.].Double‐cropped wheat (DCW) yielded 2,210 compared to 2,530 kg/ha for monocropped wheat (MCW). Conventional tillage double cropped soybeans (CT‐DCS) in 50‐cm rows yielded 1,610 compared to 1,460 kg/ha in 75‐cm rows. No‐tillage double‐cropped soybeans (NTDCS) in 50‐cm rows yielded 1,730 compared to 1,550 kg/ ha in 75‐cm rows. Conventional tillage monocropped soybeans (CT‐MCS) in 50‐cm rows yielded 2,010 compared to 1,880 kg/ha in 75‐cm rows.Water content in 120 cm of soil profile was not significantly affected during the soybean growing period by tillage and row spacings; however, lack of moisture in the soil‐seed environment resulted in poorer stands and lower yields for CT‐MCS in 1976. Water storage efficiency under wheat from the fully ripe stage of growth to late September averaged 28% for MCW. More grain production and more effective use of annual precipitation and soil stored water were achieved when wheat and soybeans were DC.

“No-till” crop production proving a most promising conservation measure

Traditional methods of soil cultivation in the Corn Belt of the United States leave the land vulnerable to erosion by wind and water. Studies at Dixon Springs have shown a very marked reduction in soil losses under the “no-till” system, both for continuous maize-growing and for double-cropped wheat and maize, a factor of considerable importance in soil conservation.