• Authors:
    • Evansf, R.
    • Lartey, R.
    • Caesar, T.
    • Sainju, U.
    • Lenssen ,A.
    • Allen, B.
  • Source: Proceedings of the 19th World Congress of Soil Science: Soil solutions for a changing world, Brisbane, Australia, 1-6 August 2010. Division Symposium 3.2 Nutrient best management practices
  • Year: 2010
  • Summary: Available water and N fertility are primary constraints to crop production in the northern Great Plains of the USA. A field trial was initiated in 2004 to compare four crop rotations in a complete factorial of two tillage and two management systems. Rotations were continuous spring wheat (SW), pea-SW, barley hay-pea-SW, and barley hay-corn-pea-SW. Tillage systems were no till and field cultivator tillage, while management systems were conventional and ecological. Conventional management included broadcast nitrogen fertilizer, standard seeding rates, and short stubble height. Ecological management practices varied by crop, and included banded nitrogen fertilizer for cereals, increased seeding rate, delayed planting date for SW, and taller stubble height. Continuous SW grain yield was 26% lower than SW in more diverse rotations. Pea grain yield was 18% lower in 2-yr rotations than in more diverse rotations. Ecologically managed SW yielded 29% less than conventionally managed SW, presumably due to the delayed planting date. Ecological management of pea resulted in 12% greater yield compared to conventional management. Tillage system rarely impacted crop yield. Yield increases in SW were related to increased N use efficiency.
  • Authors:
    • Stone, L.
    • Kelley, K.
    • Sweeney, D.
    • Kluitenberg, G.
    • Buckley ,M.
  • Source: Soil Science Society of America Journal
  • Volume: 74
  • Issue: 6
  • Year: 2010
  • Summary: The midwestern United States has >4 million ha of claypan soils. These soils often require special management because of poor infiltration, drainage, and available water supply. This study was conducted to quantify the hydrologic balance of a claypan soil and determine the effect of tillage on water balance components. It was part of an ongoing project in Labette County, Kansas, in which no-till and chisel tillage plots had been maintained since 1995. A sorghum [ Sorghum bicolor (L.) Moench]-soybean [ Glycine max (L.) Merr.] rotation was initiated in 2003, with both crops grown each year in a randomized complete block design. The plots in sorghum were instrumented to measure water content throughout the profile. Precipitation and evapotranspiration (ET) were determined at the field scale. Soil hydraulic properties and water content data were used to estimate drainage. Runoff was determined as the residual in this water balance. Evaporation from chisel tillage was up to 1 mm d -1 greater than that from no-till during the early season. This resulted in differences in surface water content and runoff. These effects were limited to the early season, however, so that the water balance for the full growing season was not significantly affected by tillage. Drainage from the claypan soil was negligible. The 2006 crop year had 23.5 cm of ET, a value greater than the in-season precipitation. The 2007 crop year had 33.5 cm of ET, a value less than the in-season precipitation. With limited drainage and storage in the claypan, 37.5 cm of runoff occurred in 2007.
  • Authors:
    • Pierzynski, G.
    • Tuppad, P.
    • Janssen, K.
    • Maski, D.
    • Douglas-Mankin, K.
  • Source: Transactions of the ASABE
  • Volume: 53
  • Issue: 5
  • Year: 2010
  • Summary: Cropland best management practice recommendations often combine tillage and nutrient application improvements to reduce nutrient losses with surface runoff. This study used the Soil and Water Assessment Tool (SWAT) model to evaluate nutrient runoff yields from conventional-till and no-till management practices with surface and deep-banded fertilizer application in a sorghum-soybean rotation. The model was calibrated for three field plots (0.39 to 1.46 ha) with different combinations of practices and validated for three field plots (0.40 to 0.56 ha) during 2001 to 2004. Daily performance of the calibrated SWAT model in simulating total N for all treatments was satisfactory for median-based Nash-Sutcliffe model efficiency (E f* of 0.54 to 0.64), good to very good for percent bias (PBIAS of 31% to 7%), and satisfactory to good for median-based root mean square error to observations standard deviation ratio (RSR* of 0.72 to 0.62). Performance was slightly lower and more variable for total P calibration (E f* of 0.42 to 0.62, PBIAS of -48% to 2%, and RSR* of 0.76 to 0.62). Monthly statistics improved for total P runoff yield compared to daily performance, but changed little for total N runoff yields, probably due to the stronger influence of outliers in the N data. Based on validation results, SWAT was more robust in simulating total N runoff yields from the treatment with less soil disturbance (NT/SB) and total P for the two treatments with more soil disturbance (NT/DB and TILL). A major concern was that SWAT predicted greater annual average total N runoff yields for no-till treatments than for tilled treatments, which was contrary to measured values at the study site. This reinforces a fundamental research issue that tillage system effects on nutrient losses are still very much uncertain and thus may not be properly modeled. The SWAT model generally underpredicted monthly total N yields for all treatments in the higher-precipitation months of May and June and overpredicted total N and total P yields from September through November. Calibration for N and P resulted in identical calibration parameters for NPERCO (1.0), RSDCO (0.05), BIOMIX (0.2), PPERCO (10), PHOSKD (175), and UBP (50) regardless of tillage practice or fertilizer application method. Together with results that calibrated parameters for runoff (CN, K sat, AWC) and erosion (C min) differed among the treatments, this study found that differences in nutrient yields among tillage and fertilizer management may be adequately modeled with SWAT by calibrating runoff and sediment yields only, and that further calibration of nutrient parameters may not improve model results.
  • Authors:
    • Sweeney, D.
    • Kelley, K.
  • Source: Crop Management
  • Issue: July
  • Year: 2010
  • Summary: Field studies were conducted from 1996 through 2006 in southeastern Kansas to evaluate the influence of previous crop [corn, Zea mays L.; grain sorghum, Sorghum bicolor (L.); and soybean, Glycine max (L.) Merr.] and tillage system (conventional versus no-till) on grain yield of hard red winter wheat ( Triticum aestivum L.) and double-crop soybean in a 2-year rotation. On average, wheat yield was greater following corn or soybean than following grain sorghum. Yield of double-crop soybean averaged 20% greater when wheat followed corn or grain sorghum than when wheat followed full-season soybean. Tillage system influenced grain yield of double-crop soybean more than it influenced wheat yield. Double-crop soybean yield often was greater for continuous no-till than for conventional or one-time no-till per cropping cycle. Soil analyses at the end of the study showed that total C and total N were greater for no-till than for conventional in the 0- to 3-inch depth, but total C and total N were greater for conventional than no-till in the 3- to 6-inch depth. In the multi-cropping systems of the eastern Great Plains, both crop rotation and tillage system can significantly influence grain yield and selected soil properties.
  • Authors:
    • Bradford, S.
    • Crohn, D.
    • Poss, J.
    • Shouse, P.
    • Segal, E.
  • Source: Agriculture, Ecosystems & Environment
  • Volume: 137
  • Issue: 3/4
  • Year: 2010
  • Summary: A nutrient management plan (NMP) field experiment was conducted to investigate the fate of nitrogen (N), phosphorus (P), potassium (K) and salts in a semi-arid environment (San Jacinto, CA). Our mechanistic approach to study NMP performance was based on comprehensive measurements of water and N mass balance in the root zone. A cereal crop rotation (wheat-rye hybrid to sorghum, Triticum aestivum L.- Secale cereale L. to Sorghum bicolor L. Moench) that does not fix atmospheric N was employed during 2007, whereas a legume crop (alfalfa, Medicago sativa L.) that forms nodules to fix N was used in 2008. Blending (2007 and 2008) and cyclic (2007) dairy wastewater (DWW) application strategies (no statistical difference in 2007) were implemented to meet crop water and N uptake. The high content of salts in DWW and accurate application of water to meet evapotranspiration ( ET) yielded salt accumulation in the root zone. Leaching these salts after the fallow period resulted in the flushing of nitrate that had accumulated in the root zone due to continuous mineralization of soil organic N. This observation suggested that a conservative NMP should account for mineralization of organic N by (i) leaching salts following harvests rather than prior to planting and (ii) maintaining soils with low values of organic N. For the wheat-rye hybrid-sorghum rotation, losses of nitrate below the root zone were minimal and the soil organic N reservoir and P were depleted over time by applying only a fraction of the plant N uptake with DWW (28-48%) and using DWW that was treated to reduce the fraction of organic N (3-10%), whereas K accumulated similar to other salts. Conversely, with alfalfa approximately 15% of the applied N was leached below the root zone and the soil organic N increased during the growing season. These observations were attributed to fixation of atmospheric N, increased root density, and applying a higher fraction of plant N uptake with DWW (76%). Collectively, our results indicate that NMPs should accurately account for water and nutrient mass balances, and salt accumulation to be protective of the environment.
  • Authors:
    • Stone, L.
    • Schlegel, A.
    • Klocke, N.
    • Blanco-Canqui, H.
    • Rice, C.
  • Source: Soil Science Society of America Journal
  • Volume: 74
  • Issue: 4
  • Year: 2010
  • Summary: Deficit irrigation is an important strategy to manage water, but its impacts on soil C sequestration and physical properties have not been well documented. We assessed changes in soil organic C (SOC) and soil inorganic C (SIC) concentrations and selected soil physical properties at two no-till experiments on Ulysses silt loam (a fine-silty, mixed, superactive, mesic Aridic Haplustoll) with <1% slope under six irrigation treatments (66, 86, 117, 152, 182, and 217 mm of water applied) at Garden City and three (127, 254, and 381 mm of water applied) at Tribune in western Kansas after 5 and 8 yr of management, respectively. For the 0- to 10-cm depth, SOC concentration and wet aggregate stability increased with an increase in irrigation amount, but bulk density, particle-size distribution, and SIC concentration were unaffected. At Garden City, the SOC pool in the 0- to 10-cm depth increased by 46% (11.2 vs. 16.4 Mg ha -1) from the lowest (66 mm) to the highest (217 mm) irrigation amount. At Tribune, the SOC concentration in the 5- to 10-cm soil depth increased by 30% when the irrigation amount increased from 127 (7.8 g kg -1) to 254 (10.2 g kg -1) mm. The amount of macroaggregates increased with an increase in the irrigation amount, particularly in the 5- to 10-cm depth. At Garden City, irrigation-induced increase in SOC concentration increased the mean weight diameter of aggregates ( r=0.66; P<0.001). Overall, deficit irrigation affected SOC concentration and soil structural development near the soil surface, but the magnitude of impacts was site specific.
  • Authors:
    • Sundermeier, A.
    • Diedrick, K. A.
    • Dygert, C. E.
    • Mullen, R. W.
    • Henry, D. C.
  • Source: Agronomy Journal
  • Volume: 102
  • Issue: 1
  • Year: 2010
  • Summary: Inclusion of a winter legume cover crop into a crop rotation has been suggested as a method to provide a substantial portion of the N requirement of the following crop. While the benefits of winter cover crops such as reduced soil erosion, increased soil organic matter, and increased mulch cover have been well documented, the N contribution to the subsequent crop has shown to be variable. The objective of this study was to determine the N contribution from a red clover (Trifolium pratense L.) cover crop following wheat (Triticum aestivum L.) to a subsequent corn (Zea mays L.) crop. The experiment was conducted at two western Ohio locations over 3 yr. At both locations, red clover was either interseeded into wheat or seeded after harvest, the red clover cover crop was eliminated with tillage or herbicide application, and corn was planted with three N rates (0, 90, and 180 kg N ha(-1)). The data revealed that for three of the four site years (when the cover crop was successfully established) there was no N contribution attributable to the presence of red clover. The one site that did show a N contribution revealed that the amount of N contributed was less than 90 kg N ha(-1). However, even when no N benefit was found, yields were improved by non-N-related rotational effects. Significant reductions in N fertilization rates following a red clover cover crop are likely to result in lost corn yield opportunities in western Ohio.
  • Authors:
    • Watkins, B.
    • Wailes, E.
    • Stiles, S.
    • Hignight, J.
    • Miller, W.
  • Source: No 57087, Staff Papers from University of Arkansas, Department of Agricultural Economics and Agribusiness
  • Issue: 2
  • Year: 2010
  • Summary: This report provides estimates of acreage, yield, and quality losses plus additional fieldwork costs related to poor weather conditions during fall harvest and season losses for grass hay within the state of Arkansas, USA. Based on yield and price data from the USDA, National Agricultural Statistical Service, quality loss estimates from local elevators, and additional fieldwork estimates from University of Arkansas extension specialists, the losses in gross receipts for crops and grass hay for 2009 are estimated to be $397 million. Cotton and sorghum are estimated to have experienced the largest negative impact per acre but total loss is greatest for soybeans ($204 million) and cotton/cottonseed ($120 million).
  • Authors:
    • Kheira, A. A. A.
    • Lamm, F. R.
    • Trooien, T. P.
  • Source: Applied Engineering in Agriculture
  • Volume: 26
  • Issue: 5
  • Year: 2010
  • Summary: A 5-year field study (2004-2008) using irrigation water from an unlined surface reservoir was conducted to examine the effect of dripline depth (0.2, 0.3, 0.4, 0.5, or 0.6 m) on subsurface drip-irrigated rotational crop production of sunflower, soybean, and grain sorghum on a deep silt loam soil in western Kansas. Additional years (1999-2003) of data were included in the analysis of long-term dripline flowrates as affected by dripline depth. Crop seed germination and plant establishment with the subsurface drip irrigation system was not examined in this field study. There were no significant differences in crop yields or yield components in any year of the study with the exception of the number of soybean pods/plant in 2007. In that year, the number of pods/plant was significantly greater for the deeper dripline depths, but this improvement was not reflected in significantly greater soybean yield due to compensation from the other yield components. Measured crop water use and calculated water productivity (yield/water use) also were not significantly affected by dripline depth for any crop in any year. Crop water use varied less than 4% and water productivity varied less than 8% with dripline depth from the mean values for a given crop within a given year, but water productivity tended to be greater for the intermediate 0.4 m dripline depth. There was a tendency for the deeper dripline depths to have greater amounts of plant available soil water and this tendency was stronger as the crop season progressed and for deeper portions of the crop root zone. However, there were neither significant differences in plant available soil water in the upper (0 to 0.9 m) and lower root zones (0.9 to 2.4 m) at physiological maturity of the crop in any year, nor in the total 2.4 m soil profile. The lack of significant differences in crop yields, water use, water productivity and plant available soil water at physiological maturity suggests that dripline depths ranging from 0.2 to 0.6 m are acceptable for crop production of these three crops on the silt loam soils of the region. Measurements of plot dripline flowrates during the period 1999 through 2008 indicated a tendency for deeper disciplines to have reduced flowrates and these flowrate reductions were statistically significant in 2001, 2006, 2007, and 2008. Although the reason for these plot flowrate reductions cannot be fully ascertained, it seems likely they were caused by emitter clogging related to an interaction between dripline depth and irrigation water quality for which the rationale was not determined.
  • Authors:
    • Honeycutt, C. W.
    • Griffin, T. S.
    • Larkin, R. P.
  • Source: Plant Disease
  • Volume: 94
  • Issue: 12
  • Year: 2010
  • Summary: Seven different 2-year rotations, consisting of barley/clover, canola, green bean, millet/rapeseed, soybean, sweet corn, and potato, all followed by potato, were assessed over 10 years (1997-2006) in a long-term cropping system trial for their effects on the development of soilborne potato diseases, tuber yield, and soil microbial communities. These same rotations were also assessed with and without the addition of a fall cover crop of no-tilled winter rye (except for barley/clover, for which underseeded ryegrass was substituted for clover) over a 4-year period. Canola and rapeseed rotations consistently reduced the severity of Rhizoctonia canker, black scurf, and common scab (18 to 38% reduction), and canola rotations resulted in higher tuber yields than continuous potato or barley/clover (6.8 to 8.2% higher). Addition of the winter rye cover crop further reduced black scurf and common scab (average 12.5 and 7.2% reduction, respectively) across all rotations. The combined effect of a canola or rapeseed rotation and winter rye cover crop reduced disease severity by 35 to 41% for black scurf and 20 to 33% for common scab relative to continuous potato with no cover crop. Verticillium wilt became a prominent disease problem only after four full rotation cycles, with high disease levels in all plots; however, incidence was lowest in barley rotations. Barley/clover and rapeseed rotations resulted in the highest soil bacterial populations and microbial activity, and all rotations had distinct effects on soil microbial community characteristics. Addition of a cover crop also resulted in increases in bacterial populations and microbial activity and had significant effects on soil microbial characteristics, in addition to slightly improving tuber yield (4% increase). Thus, in addition to positive effects in reducing erosion and improving soil quality, effective crop rotations in conjunction with planting cover crops can provide improved control of soilborne diseases. However, this study also demonstrated limitations with 2-year rotations in general, because all rotations resulted in increasing levels of common scab and Verticillium wilt over time.