No-till Sorghum Research Articles

Economics of alternative tillage systems in dryland crop rotations in U.S. Great Plains

Tillage systems change as new findings or obstacles arise, from conventional tillage (CT) in the past to conservation tillage [reduced tillage (RT) and no-tillage (NT)] to possibly occasional tillage (OT)]. This research was needed to answer the economics of these various tillage systems and how the re-introduction of a single tillage changes the cost and revenue of long-term NT. An Economic analyses of these alternative tillage systems, based on long-term field research, is limited. The specific objective of this research was to quantify the relative economic advantages of various tillage systems (CT, RT, NT, and OT) in a wheat-sorghum-fallow (W-S-F) rotation in the central Great Plains. Results of two long-term field research studies conducted in western Kansas were used for this analysis. The first study was conducted from 2001 to 2018 to compare CT, RT, and NT systems and the second study from 2014 to 2018 at two locations to compare NT with OT. Results showed average NT sorghum yields were more than double the average yields of CT and 58 % greater than RT. There were no significant differences in wheat or sorghum yields between NT and OT. Total cost of production for the W-S-F system increased in the order NT>RT>CT. However, the NT system had the greatest average return, about $76 and $146 ha-1 greater than RT and CT, respectively. Net returns were not different between NT and OT. In support with our initial hypothesis, we concluded that a NT system has yield and profit advantages over RT and CT. And if a onetime OT is necessary in a long-term NT system, crop yields and return will not be significantly affected in the first 5 years after the OT.

Yield Responses of Grain Sorghum and Cowpea in Binary and Sole Cultures under No-Tillage Conditions in Limpopo Province

Climate change is severely disrupting ecosystem services and crop productivity, resulting in lower crop growth and yields. Studies have emphasized the importance of assessing conservation practices through crop modelling to improve cropland productivity. There is a lack of accurate information in the performance of conservation practices as well as data for improved crop modelling. No-tillage sorghum–cowpea intercrop experiments were established to assess the productivity of four sorghum cultivars and cowpea at two densities of 37,037 and 74,074 per plants and generate data for improved crop modelling. The leaf area index (LAI) varied in sorghum cultivars and cowpea densities during the two growing seasons. Cultivars Enforcer and NS5511 produced the highest grain yields of 4338 kg per ha and 2120 kg per ha, respectively, at Syferkuil. Ofcolaco’s Enforcer and Avenger were the highest yielding cultivars at Ofcolaco, with mean yields of 2625 kg per ha and 1191 kg per ha, respectively. At Syferkuil, cowpea yield was 93% and 77% more in sole compared to binary cultures during the growing seasons at Syferkuil. At Ofcolaco, sole yielded approximately 96% more grain than binary. The findings confirm that for the sorghum–cowpea intercrop to improve overall system productivity, cowpea density should be increased.

Reduction of Nitrogen Fertilizer Requirements and Nitrous Oxide Emissions Using Legume Cover Crops in a No-Tillage Sorghum Production System

Nitrous oxide (N2O) emission from denitrification in agricultural soils often increases with nitrogen (N) fertilizer and soil nitrate (NO3−) concentrations. Our hypothesis is that legume cover crops can improve efficiency of N fertilizer and can decrease N2O emissions compared to non–cover crop systems. The objectives of this study were to (a) evaluate the performance of summer leguminous cover crops in terms of N uptake and carbon (C) accumulation following winter wheat and (b) to quantify the effects of summer leguminous cover crops and N fertilizer rates on N2O emissions and grain yield of the subsequent grain sorghum crop. Field experiments were conducted in the context of a wheat-sorghum rotation for two seasons in Kansas. Treatments consisted of double-cropped leguminous cover crops following winter wheat harvest with no fertilizer applied to the following grain sorghum or no cover crop after wheat harvest and N fertilizer rates applied to the grain sorghum. The cover crops were cowpea (Vigna unguiculata L. Walp.), pigeon pea (Cajanus cajan L. Millsp.), and sunn hemp (Crotalaria juncea L.). The three N treatments (were 0, 90, and 180 kg·N·ha−1). Fallow systems with 90 and 180 kg·N·ha−1 produced significantly greater N2O emissions compared with cropping systems that received no N fertilizer. Emissions of N2O were similar for various cover crops and fallow systems with 0 kg·N·ha−1. Among cover crops, pigeon pea and cowpea had greater C accumulation and N uptake than sunn hemp. Grain yield of sorghum following different cover crops was similar and significantly higher than fallow systems with 0 kg·N·ha−1. Although fallow systems with 90 and 180 kg·N·ha−1 produced maximum sorghum grain yields, N2O emissions per unit of grain yield decreased as the amount of N fertilizer was reduced. We conclude that including leguminous cover crops can decrease N fertilizer requirements for a subsequent sorghum crop, potentially reducing N2O emissions per unit grain yield and providing options for adaptation to and mitigation of climate change.

Surface Detention on Cropland, Rangeland, and Conservation Reserve Program Areas

Abstract. One of the factors contributing to overland flow on upland areas is water stored temporarily in a thin sheet on the soil surface as surface detention. This study was conducted to quantify surface detention on selected cropland, rangeland, and Conservation Reserve Program (CRP) sites. Surface detention was determined from the recession portion of runoff hydrographs corresponding with the period when rainfall had ceased but runoff continued. The hydrographs were generated from six previously reported rainfall simulation studies conducted on paired 3.7 m wide × 10.7 m long plots on which approximately 128 mm of rainfall was applied. Surface detention values were found to increase as crop residue or vegetative cover increased. Eleven fallow cropland sites in the eastern U.S. had surface detention values that varied from 1.7 to 4.6 mm. Surface detention on plots in southwestern Oklahoma containing Old World bluestem, no-till wheat, and conservation-till wheat was 9.4, 7.3, and 5.2 mm, respectively. No-till sorghum, tilled sorghum, no-till wheat, and tilled wheat plots in southeast Nebraska had surface detention values of 6.7, 4.5, 6.7, and 4.6 mm, respectively. Mean surface detention on no-till and tilled cropland sites in southwest Iowa containing corn residue was 7.2 and 5.9 mm, respectively. CRP study sites in southwestern Iowa had mean surface detention of 10.8 mm. When data from the six field studies were combined, mean surface detention values for fallow cropland, tilled cropland, no-till cropland, rangeland, and CRP areas were 3.1, 5.0, 6.9, 9.6, and 10.8 mm, respectively. Keywords: Depressional storage, Hydrographs, Hydrologic modeling, Overland flow, Runoff volume, Surface detention.

High quality residues from cover crops favor changes in microbial community and enhance C and N sequestration

The objective of the study was to evaluate the effect of a change in management on the soil microbial community and C sequestration. We conducted a 3-year field study in La Pampa (Argentina) with rotation of sorghum (Sorghum bicolor) in zero tillage alternating with rye (Secale cereale) and vetch (Vicia villosa ssp. dasycarpa). Soil was sampled once a year at two depths. Soil organic matter fractions, dissolved organic matter, microbial biomass (MBC) and community composition (DNA extraction, qPCR, and phospholipid FAME profiles) were determined. Litter, aerial- and root biomass were collected and all material was analyzed for C and N. Results showed a rapid response of microbial biomass to a bacterial dominance independent of residue quality. Vetch had the highest diversity index, while the fertilized treatment had the lowest one. Vetch–sorghum rotation with high N mineralization rates and diverse microbial community sequestered more C and N in stable soil organic matter fractions than no-till sorghum alone or with rye, which had lower N turnover rates. These results reaffirm the importance of enhanced soil biodiversity for maintaining soil ecosystem functioning and services. The supply of high amounts of N-rich residues as provided by grass–legume cover crops could fulfill this objective.

Land-based greenhouse gas emission offset and leakage discounting

This paper examines leakage from agricultural greenhouse gas reduction programs stimulated by reductions in regional commodity supply. This paper develops an extension of the leakage discount formula in Murray et al. (2004) that incorporates changes in input (land) usage rather than product output (crop or forest product quantity). Additionally the leakage discount developed here allows for land conversion and production replacement involving multiple alternative uses. In an empirical application in the Southeast Texas we compute leakage discounts of 14.8% for the conversion of rice to no-till sorghum and 14.9% for rice to pasture program. Most of the sources of GHG offset leakage come from conversions of cotton to rice and pasture to rice in the other regions.

Runoff Losses of N and P After Low Phosphorus Swine Slurry Application to No-Tillage Sorghum

Abstract Swine (Sus scrofa) manure can serve as a fertilizer source for crop production, but it typically contains more P relative to N than the crop requires, creating the potential for P losses in runoff. A 3-year study was conducted to compare runoff losses of NO3-N, NH4-N, total N, dissolved P, and total P under natural rainfall conditions from no-tillage sorghum plots [Sorghum bicolor (L.) Moench] receiving inorganic fertilizer, manure from swine fed low-phytate corn (Zea mays L.) diet, or manure from swine fed a traditional corn diet. Runoff (26.5 mm in 1999, 14.2 mm in 2000, and 1.6 mm in 2001), sediment loss (2.9 kg ha−1 in 1999, 0.9 kg ha−1 in 2000, and 0.4 kg ha−1 in 2001), and runoff nutrient losses differed among years but were similar among treatments within a year. Runoff losses of NO3-N (5.3 g ha−1 in 1999, 1.0 g ha−1 in 2000, and 2.6 g ha−1 in 2001), NH4-N (2.9 g ha−1 in 1999, 0.6 g ha−1 in 2000, and 5.6 g ha−1 in 2001), total N (89.7 g ha−1 in 1999, 8.4 g ha−1 in 2000, and 100.2 g ha−1 in 2001), dissolved P (1.5 g ha−1 in 1999, 0.5 g ha−1 in 2000, and 3.1 g ha−1 in 2001), and total P (3.8 g ha−1 in 1999, 0.9 g ha−1 in 2000, and 3.5 g ha−1 in 2001) from these plots represented less than 1% of that applied each year. Although use of low-phytate corn reduces manure P content, it did not decrease runoff P under these no-tillage conditions.

Between-row Mowing Systems Control Summer Annual Weeds in No-till Grain Sorghum

In previous research, use of PRE soil residual herbicides was reduced 50% in no-till corn and soybean by banding herbicides over crop rows followed by mowing weeds growing between rows two times. The research goals were (1) to determine whether such between-row mowing systems adequately controlled weeds and prevented grain yield loss in other competitive field crops, such as no-till grain sorghum, and (2) to compare broadcast herbicide treatments with between-row mowing systems. PRE atrazine plus dimethenamid at relative rates of 0.75× and 1× (where 1× = 1.7 plus 1.3 kg ai/ha, respectively) were band-applied over rows shortly after planting followed by two between-row mowings close to the soil surface. In 2 of 3 yr in Missouri, this system controlled giant foxtail and common waterhemp as well as broadcast herbicides in no-till sorghum. In 2 of 3 yr, between-row mowing systems also prevented yield loss in no-till sorghum as well as both broadcast herbicides at the same rates and the weed-free check.Nomenclature: Atrazine; dimethenamid; giant foxtail, Setaria faberii (L.) Beauv. SETVI; common waterhemp, Amaranthus rudis Sauer. AMATA; corn, Zea mays L. ZEAMX; sorghum, Sorghum bicolor (L.) Moench SORVU ‘Northup King GS10’and ‘Pioneer 84G62’; soybean, Glycine max (L.) Merr.

Agroecological analysis and economic benefit of organic resources and fertiliser in till and no-till sorghum production after a 6-year fallow in semi-arid West Africa

A field experiment was conducted in Gampela (Burkina Faso) in 2000 and 2001 to assess the impact of organic and mineral sources of nutrients and combinations thereof in optimising crop production in till and no-till systems and to assess the economic benefit of these options. The study showed that under conditions of rainfall deficiency, the use of a single organic resource at an equivalent dose of 40 kg N ha−1 better secured crop yield than the application of an equivalent amount as urea-N, while a combination of organic resources and fertiliser was better in increasing crop yield than the application of the same N amount in the form of urea. In a year of rainfall deficiency, a mix of organic resources and fertiliser in both till and no-till systems increased crop water use efficiency, with the result that the farmer was able to purchase only half of the normal quantity of N fertiliser to obtain a higher yield that he would have done when all of the N was supplied in the form of urea. Under conditions where soil N is deficient, an economic benefit was achieved when urea was combined with easily decomposable organic material (e.g. sheep dung); mixing the urea at a dose of 40 kg N ha−1 with maize straw was not sufficient in alleviating the negative interaction due to the enhanced N immobilisation. The results demonstrate that the use of N fertiliser alone was risky and that a higher yield, with the accompanying economic benefit, was scarcely achieved under the prevailing rainfall conditions. The application of soil and water conservation measures can contribute greatly to increasing the economic benefit of mineral, organic or combined organic and mineral-derived nutrient application under semi-arid conditions.

Changes in Soil Attributes Following Low Phosphorus Swine Slurry Application to No-Tillage Sorghum

Swine (Sus scrofa) slurry can serve as an excellent fertilizer source. Application at rates to meet crop N requirements can result in excess soil P due to low manure N/P ratios. Low phytate corn (LPC) (Zea mays L.) stores a greater proportion of P as phosphate than does traditional corn (TC) increasing bioavailability of P in pig feed grain. Improved utilization of feed P reduces P concentration in manure and soil P accumulation. However, the potential effects of LPC manure on other soil properties are not known. Changes in soil attributes over 3 yr were compared for soils receiving LPC manure, TC manure, inorganic fertilizer, and no nutrients in no-tillage sorghum [Sorghum bicolor (L.) Moench] on a Sharpsburg clay loam (fine, smectitic, mesic Typic Argiudolls). Soil physical properties exhibited values that should not inhibit crop growth. Several soil chemical properties differed by year and treatment. Particulate organic matter (POM), NO 3 -N, pH, and extractable P increased with manure additions. Extractable P content was greater with addition of TC than LPC manure. Soil chemical properties exhibited values acceptable for crop production, but increasing extractable P increases the potential for environmental contamination. Biological soil properties varied in their response to treatments. Microbial biomass C decreased in the control and increased in manure treatments. The Soil Management Assessment Framework (SMAF) was used to conduct a dynamic soil quality assessment. The SMAF index values were similar across years in the control and inorganic fertilizer treatments and increased in both manure treatments. Manure additions improved soil properties affecting crop production, with P accumulation and the potential for environmental contamination being lower with LPC manure. LPC manure applied at rates to meet crop N requirements will have slower soil P accumulation rates and a lower potential for P contamination of the environment.

Biologically Defined Soil Organic Matter Pools as Affected by Rotation and Tillage

The importance of soil organic matter is well recognized; however, changes in C and N fractions are inadequately quantified. The objective of this study was to determine tillage and crop rotation effects on soil organic C and N fractions from a long-term (27-year) study in eastern Kansas. Cropping systems included continuous and rotation sequences of wheat (Triticum aestivum L.), grain sorghum (Sorghum bicolor (L.) Moench), and soybean (Glycine max (L.) Merrill) on a Muir silt loam (fine-silty, mixed, mesic Cumulic Haplustolls). Tillage included conventional (CT), reduced (RT), and no-till (NT). Total C and N (CT and NT) were determined on all treatments. Mineralizable C and N (Co and No) and microbial biomass C and N were determined for the NT and CT soybean and sorghum rotations. Cropping systems that included wheat contained the greatest amount of CT and NT. Continuous wheat contained 2910 g C m−2 and 287 g N m−2, compared to 2225 g C m−2 and 222 g N m−2 (0–15 cm) for continuous soybean. No-tillage contained 1128 g C m−2 and 109 g N m−2 at 0–5 cm compared to 918 g C m−2 and 87 g N m−2 for CT. Sorghum contained 51% more Co than soybean, and NT accounted for 59% more Co than CT. More crop residue was produced and retained in rotations that included sorghum. No-tillage increased C 2440 kg ha−1, while CT increased C 340 kg ha−1 across all soybean/sorghum rotations. The highest sequestration rate (122 kg C ha−1 y−1) was observed with NT sorghum and was equivalent to ∼3.2% of the plant material (root and shoot, less gain harvest) remaining in the soil annually.

Enhancing Agriculture?s Potential to Sequester Carbon: A Framework to Estimate Incentive Levels for Reduced Tillage

The objectives of this study are to develop and test a framework to estimate the cost of enhancing agriculture’s potential as a carbon sink through the implementation of reduced tillage productive systems. A major factor inhibiting the adoption of reduced tillage practices is the additional risk perceived by farmers and its effect on net revenues. The expected utility model provides a useful means for evaluating risk–return tradeoffs of agricultural production systems. Incentive levels required to induce implementation of reduced tillage practices are calculated using estimated certainty equivalents. The framework developed is applied to eight case studies across the United States. Results indicate that in the Corn Belt, the required incentive payment for corn/soybeans would have to be $10.20 and $8.30 per acre for poorly drained and well-drained soils, respectively. Continuous corn incentive payments for poorly drained soils were found to be $40.40 and $26.70 for well-drained soils. In the central Great Plains, an incentive level of $14.60 per acre was required for continuous sorghum. Although the mean yields for conventional and reduced tillage practices are fairly close in this case, the higher costs associated with no-till sorghum result in the high incentive level. In the wheat/fallow and wheat/sorghum/fallow rotations of the western Great Plains, the yields associated with no-till were higher than intensive till. Thus, incentive levels near $6.00 per acre are the result of higher costs of no-till in these rotations. In the Mississippi River Corridor region, results show that the switch from corn/soybean to the same no-till rotation would require an incentive level of $7.90 per acre.

Integração agricultura-pecuária em plantio direto: produção de forragem e resíduo de palha após pastejo

O objetivo deste trabalho foi verificar, no sistema integração agricultura-pecuária, a possibilidade de utilizar uma cultura para pastejo cujos resíduos permitam produção de palha suficiente para a manutenção do plantio direto, bem como avaliar a produção da forrageira e do resíduo em diferentes distâncias em relação ao centro do pivô, em três épocas, e o desempenho econômico do sistema. Avaliaram-se o impacto do pastejo rotacionado de sorgo forrageiro em plantio direto, sob irrigação em um pivô central de 75 ha, sobre a produção de matéria seca do sorgo forrageiro, a quantidade de resíduos, o custo de produção e o ganho de peso animal. O ensaio foi conduzido num Latossolo Vermelho Distrófico. O delineamento experimental utilizado foi o de blocos ao acaso, com parcelas subdivididas, com quatro tratamentos principais: locais de amostragem em diferentes distâncias em relação ao centro do pivô; três tratamentos secundários (ciclos de pastejos) e sete repetições (sete piquetes de 9,37 ha para pastejo, dispostos na forma de "pizza"). Os resultados permitiram concluir que: a produção do sorgo forrageiro foi suficiente para permitir um ganho 621 kg ha-1 de peso vivo e a quantidade de resíduos de sorgo após o pastejo foi suficiente para suprir o aporte anual de matéria seca de palha necessária para a manutenção do plantio direto; a área, após os pastejos, continuou passível de ser explorada no sistema de plantio direto, e o sistema pesquisado mostrou-se técnica e economicamente viável.

CROP PRODUCTION SYSTEMS TO CONTROL EROSION AND REDUCE RUNOFF FROM UPLAND SILTY SOILS

Soil erosion remains the most significant threat to long-term agricultural sustainability. In order to determine if highly erodible silty upland soils could be row-cropped while conforming to the conservation provisions of the Food Security Act, we measured natural-rainfall runoff and soil loss for six years from eight alternative cropping systems on sixteen 4% slope plots and three small watersheds in north Mississippi. Several conservation cropping systems slightly reduced runoff and greatly decreased erosion on these soils. On erosion plots, no-till for soybean, corn, or sorghum reduced soil loss by more than 80% and no-till for cotton by more than 70% as compared to conventionally tilled soybean. Ridge-till was more than twice as erodible as no-till, while no-till soybean double-cropped with wheat was least erodible of the eight systems studied. On small watersheds, annual sediment yield ranged up to about 30 t/ha for conventional tillage soybean with buffer strips and grassed waterways but, after the first year, never exceeded 1 t/ha for no-till soybean. However, no-tillage alone was not adequate to control concentrated-flow headcuts. Most conservation systems decreased runoff by at least 10%. No-till sorghum or corn with a vetch cover crop generally decreased runoff most, and doublecropped soybean-wheat had less than 75% of the runoff of conventional soybean. Greatest reductions occurred during years of higher runoff amounts. Runoff per unit of area from the watersheds was much greater than from comparable erosion plots, indicating that extrapolation of plot data to field areas merits careful consideration of their relative soil and topographic characteristics. This research demonstrated that several no-tillage cropping systems can keep erosion below tolerable limits, reduce runoff somewhat, and be economically profitable. When combined with complementary conservation practices such as waterways and grass hedges, they provide methods for achieving both effective conservation and sustainable production when intensively cropping erodible upland soils of the southern United States.

RUNOFF AND EROSION FOLLOWING FIELD APPLICATION OF BEEF CATTLE MANURE AND COMPOST

Manure or compost from beef cattle feedlots can be excellent sources of nutrients and organic matter when added to soils. This study was conducted to determine the effect of a single application of manure and compost on runoff and erosion under no-till and tillage conditions. Tillage consisted of a single disking operation up and down the slope on a Sharpsburg soil which was cropped to grain sorghum or wheat the previous season. Manure and compost were applied at rates required to meet corn fertility requirements. Additional experimental treatments included the application of inorganic fertilizer and an untreated check. The addition of manure or compost to the no-till plots containing sorghum or wheat residue resulted in significant reductions in residue cover. However, residue cover following tillage was unaffected by the earlier addition of manure or compost. Runoff and erosion from simulated rainfall were not significantly influenced by the single application of manure or compost. On the no-till sorghum residue treatments, total solids transport represented 5.1% and 3.3% of the mass of applied manure and compost, respectively. Total solids transport was 1.3% and 1.4% of the mass of applied manure and compost, respectively, on the no-till wheat residue treatments.

Tillage-induced soil carbon dioxide loss from different cropping systems

Tillage of soils often decreases soil organic matter content and increases the flux of carbon dioxide (CO 2) from soils. Our objectives were (1) to measure short-term, tillage-induced soil CO 2 flux from different cropping systems using two instruments, a soil chamber (about 10 −3 m 3) and a canopy chamber (3.25 m 3), and (2) to examine the interactions between cumulative short-term soil CO 2 flux and soil N transformations. Measurements were made on 6 and 7 May 1994 for three cropping systems (coastal bermudagrass ( Cynodon dactylon (L.) Pers.), continuously cultivated sorghum ( Sorghum bicolor (L.) Moench), and no-till sorghum) that had three different tillage practices (molbboard plow, chisel plow, and untilled as the control) imposed on a vertisol at the Blackland Research Center, Temple, Texas, USA. The soil CO 2 flux was calculated from the rate of CO 2 concentration increase inside each chamber. Soil inorganic N content (NO 2N, NO 3N, and NH 4N) was measured from soil cores collected immediately preceding tillage and at 8, 24, and 102 h thereafter. The CO 2 flux over a 24 h period measured by both methods was greatest immediately after tillage, but maximum soil chamber fluxes were only about 10% of those measured by the canopy chamber. The large differences between chambers are a concern, and probably were related to the inability of the soil chamber to make a representative measurement for tilled surfaces and to the increased turbulence and possible associated pressure effects inside the canopy chamber. Increased soil surface area under the canopy chamber caused by increased soil surface roughness may also explain observed chamber differences. Fluxes were greatest in the bermudagrass and least in the continuously cultivated sorghum. Fluxes in the moldboard plow treatment were usually the greatest, and fluxes in the untiled treatment were considerably smaller than fluxes from either tilage treatment. For the first 24 h after tillage, there was no relationship between cumulative CO 2 flux and the change of inorganic N. Thus, to the extent that these inorganic N content changes reflect microbial activity, the short-term CO 2 flux from tilled soils is controlled more by mass flow processes related to a tillage-induced change in porosity than to immediate microbial activity.

Dryland Corn vs. Grain Sorghum in Western Kansas

Dryland crop yields in the U.S. Great Plains are limited by low precipitation and high potential evapotranspiration. In western Kansas wheat (Triticum aestivum L.) and grain sorghum [Sorghum bicolor (L.) Moench] are grown commonly, whereas corn (Zea mays L.) is believed to lack sufficient drought and heat tolerance for dryland production. A study was conducted near Garden City, KS, from 1991 through 1995 to determine whether corn could be grown successfully. No-till (NT) and conventional-till (CT) corn and grain sorghum were compared. In the driest year, sorghum yielded 137% more than corn with CT and 85% more with NT, but in 3 of 5 yr, NT corn yielded from 34% to 112% more than NT sorghum. In the remaining year, CT sorghum yielded more than CT corn, but NT yields did not differ. Overall, NT increased corn yields by 28% and net return by 69%, but increased sorghum yields by only 11% and had no effect on net return. No-till corn yielded 28% more than NT sorghum and produced 169% more net return, whereas CT corn yielded 11% more than CT sorghum and produced 48% more net return. Dryland corn can be grown in western Kansas if lower yields and returns are accepted in dry years in exchange for yields and returns considerably higher than those of sorghum in favorable years. No tillage will substantially increase yields in most years and is essential to assure adequate corn yields in dry years.

Dryland No-Tillage Winter Wheat Response to Planter Type

Crop planting becomes increasingly difficult as surface residue amounts increase, as with conservation tillage. Planters for such conditions are available, but costly. With relatively low residue amounts, as for winter wheat (Triticum aestivum L.) and grain sorghum (Sorghum bicolor (L.) Moeneh.] grown in rotation on dryland, it was hypothesized that drills used under conventional tillage conditions could satisfactorily plant wheat into no-tillage sorghum residues. Objectives of this study were to test this hypothesis. The information would show whether different planting equipment is needed when switching to a conservation tillage system. Drills were John Deere 8200 (Deere and Co., Moline, IL) with single-disk, Graham-Hoeme PD-160 (United Farm Tooh/Oelwein, IA) and Fabco M-10 (Fabco Ltd., Swift Current, SK, Canada) with double-disk, and International 7100 (J. I. Case, Racine, WI) with hoe openers. No drill provided 1.5 in. (target depth) of seed coverage; it was least (0.75 in.) with the John Deere, which moved more soil from the seed row than other drills. The number of seedlings emerged was not affected by drill types. Mean yields with the John Deere (2000 Ib/acre grain; 4200 Ib/acre residue) were lower than with other drills (2410 to 2670 Ib/acre grain; 4900 Ib/acre for residue). Differences in seed coverage depth and soil removal from the drill row possibly caused the yield differences. A suitable drill should be used for planting wheat under conservation tillage, but using a heavy-weight drill, as the Fabco, is not warranted when grain sorghum residues on dryland are similar to the amounts present under the conditions of this study (4900 Ib/acre).

Evaluation of Selected Hopper Box and Insecticide Treatments for Control of the Red Imported Fire Ant in Grain Sorghum, 1995

Abstract Selected hopper box and insecticide treatments were evaluated for management of the RIFA in no-till sorghum at the Macon Ridge Location of the Northeast Research Station in Franklin Parish, LA. Grain sorghum was planted no-till with a John Deere 7300 planter into a bermuda grass sod containing a high density of RIFA mounds. The test was planted on 19 May in a RCB design with 4-row plots (13.33 ft X 15 ft) and 4 replications. Lorsban, Admire and Furadan were applied as in-furrow sprays at planting (IFSAP) with a CO2 charged system calibrated to deliver 5 gpa at 35 psi through 8002E flat fan nozzles (1/row). Lorsban was also applied as pre-emergence surface spray (PRE) immediately post-plant with a CO2 charged system calibrated to deliver 10 gpa at 35 psi through 8001 flat fan nozzles (1/row) in a band 20 inches wide over the row center. Other treatments were applied either as in-furrow granules at planting (IFGAP), T-banded granules at planting (T-BAND) or seed treatments (SEEDT). RIFA densities were estimated on 29 May by placing an unruled index card (3X5 inches) baited with peanut butter in each plot and recording the number of ants attracted after 2 h. Plant population densities were recorded on 15 Jun by sampling the 2 center rows. Plant heights were estimated on 15 Jun by measuring 20 plants in each plot. Intra-row skips between plants were recorded on 15 Jun by counting the number of skips > 12 inches in the 2 center rows. Sorghum seed yields were obtained on 9 Aug from the 2 center rows of each plot.

Evaluation of Selected Insecticides for Control of Red Imported Fire Ant in Grain Sorghum, 1994

Abstract The efficacy of selected insecticides and application methods for management of RIFA in no-till sorghum was evaluated in two tests at the Macon Ridge Branch of the Northeast Research Station in Franklin Parish, LA. Both tests were planted in a Gigger silt loam (pH = 5.0, 1.4% organic matter) in an area that had been covered with a hairy vetch (Vicia villosa) winter cover crop. Plots consisting of 4 rows (40 inch centers) by 35 ft were planted on 28 Apr in a RCB with 4 replications. Lorsban 4EC and Asana XL were applied as in-furrow sprays at planting (IFSAP) with a CO2 charged system calibrated to deliver 5 gpa at 35 psi through 8002E flat fan nozzles (1/row). Lorsban 4EC and Asana XL were also applied as pre-emergence surface sprays (PRE) with a CO2 charged system calibrated to delvier 10 gpa at 35 psi through 8001 flat fan nozzles (1/row) in a 20 inch band immediately post-plant. Other insecticide treatments were applied either as in-furrow granules at planting (IFGAP), T-banded granules at planting (T-BAND) or seed treatments (SEEDT). RIFA numbers were estimated on 11 May by placing an unruled index card (3 × 5 inches) baited with peanut butter in each plot and recording the no. of ants attracted after 3 h. Plant stand densities were recorded on 19 May by sampling the entire 2 center rows in each plot. Plant heights were estimated on 25 May by measuring 20 plants in each plot. Sorghum seed yields were recorded on 15 Aug by harvesting the 2 center rows of each plot.