• Authors:
    • Alluvione, F.
    • Del Grosso, S. J.
    • Halvorson, A. D.
  • Source: Better Crops with Plant Food
  • Volume: 93
  • Issue: 1
  • Year: 2009
  • Summary: Research shows that application of N fertilizer increases nitrous oxide (N2O) emissions linearly from irrigated cropping systems in Colorado. Conventional-till continuous corn had a higher level of N2O emissions than no-till continuous corn. Inclusion of soybean or dry bean in the no-till corn rotation increased the level of N2O emissions during the corn year of the rotation. Use of controlled release and stabilized N sources reduced N2O emissions under no-till when compared to urea and UAN fertilizer sources. Results of this work indicate that there are crop and fertilizer N management alternatives to reduce N2O emissions from irrigated systems.
  • Authors:
    • Lory, J.
    • Ketterings, Q.
    • Koelsch, R.
    • Helmers, M.
  • Volume: 2010
  • Year: 2009
  • Authors:
    • Norem, D.
    • Brown,S.
    • Cotton,M.
    • Messner,S.
    • Berry,F.
  • Year: 2009
  • Authors:
    • Horwath, W.
    • Kallenbach, C.
    • Assa, J.
    • Burger, M.
  • Year: 2009
  • Authors:
    • Folley, J. A.
    • Kucharik, C. J.
    • Cahill, K. N.
  • Source: Ecological Applications
  • Volume: 19
  • Issue: 8
  • Year: 2009
  • Summary: We investigated carbon cycling and ecosystem characteristics among two prairie restoration treatments established in 1987 and adjacent cropland, all part of the Conservation Reserve Program in southwestern Wisconsin, USA. We hypothesized that different plant functional groups (cool-season C3 vs. warm-season C4 grasses) between the two prairie restoration treatments would lead to differences in soil and vegetation characteristics and amount of sequestered carbon, compared to the crop system. We found significant (P < 0.05) differences between the two prairie restoration treatments in soil CO2 respiration and above- and belowground productivity, but no significant differences in long-term (~16-year) carbon sequestration. We used a biometric approach aggregating short-term observations of above- and belowground productivity and CO2 respiration to estimate total net primary production (NPP) and net ecosystem production (NEP) using varied methods suggested in the literature. Net ecosystem production is important because it represents the ecosystem carbon sequestration, which is of interest to land managers and policymakers seeking or regulating credits for ecosystem carbon storage. Such a biometric approach would be attractive because it might offer the ability to rapidly assess the carbon source/sink status of an ecosystem. We concluded that large uncertainties in (1) estimating aboveground NPP, (2) determining belowground NPP, and (3) partitioning soil respiration into microbial and plant components strongly affect the magnitude, and even the sign, of NEP estimates made from aggregating its components. A comparison of these estimates across treatments could not distinguish differences in NEP, nor the absolute sign of the overall carbon balance. Longer-term quantification of carbon stocks in the soil, periodically linked to measurements of individual processes, may offer a more reliable measure of the carbon balance in grassland systems, suitable for assigning credits.
  • Authors:
    • Smith, R.
    • Cahn, M.
  • Year: 2009
  • Authors:
    • Lu, Y.
    • Conklin, A. E.
    • Teasdale, J. R.
    • Hanson, J. C.
    • Hima, B. L.
    • Cavigelli, M. A.
  • Source: Renewable Agriculture and Food Systems
  • Volume: 24
  • Issue: 2
  • Year: 2009
  • Summary: Interest in organic grain production is increasing in the United States but there is limited information regarding the economic performance of organic grain and forage production in the mid-Atlantic region. We present the results from enterprise budget analyses for individual crops and for complete rotations with and without organic price premiums for five cropping systems at the US Department of A(Agriculture-Agricultural Research Service (USDA-ARS) Beltsville Farming Systems Project (FSP) from 2000 to 2005. The FSP is a long-term cropping systems trial established in 1996 to evaluate the sustainability of organic and conventional grain crop production. The five FSP cropping systems include a conventional. three-year no-till corn (Zea mays L.)-rye (Secale cereale L.) cover crop/soybean (Glycine max (L.) Merr)-wheat (Triticum aestivum L.)/soybean rotation (no-till (NT)), a conventional, three-year chisel-till corn-rye/soybean-wheat/soybean rotation (chisel tillage (CT)), a two-year organic hairy vetch (Vicia villosa Roth)/corn-rye/soybean rotation (Org2), a three-year organic vetch/corn-rye/soybean-wheat rotation (Org3) and a four- to six-year organic corn-rye/soybean-wheat-red clover (Trifolium pratense L.)/orchard grass (Dactylis glomerata L.) or alfalfa (Medicago sativa L.) rotation (Org4+). Economic returns were calculated for rotations present from 2000 to 2005, which included some slight changes in crop rotation sequences due to weather conditions and management changes additional analyses were conducted for 2000 to 2002 when all crops described above were present in all organic rotations. Production costs were, in general, greatest for CT, while those for the organic systems were lower than or similar to those for NT for all crops. Present value of net returns for individual crops and for full rotations were greater and risks were lower for NT than for CT. When price premiums for organic crops were included in the analysis, cumulative present value of net returns for organic systems (US$3933 to 5446 ha(-1), 2000 to 2005. US$2653 to 2869 ha(-1), 2000 to 2002) were always Substantially greater than for the conventional systems (US$1309 to 1909 ha(-1),2000 to 2005; US$634 to 869 ha(-1), 2000 to 2002). With price premiums, Org2 had greater net returns but also greater variability of returns and economic risk across all years than all other systems, primarily because economic Success of this short rotation was highly dependent on the success of soybean, the crop with the highest returns. Soybean yield variability was high due to the impact of weather on the success of weed control in the organic systems. The longer, more diverse Org4+ rotation had the lowest variability of returns among organic systems and lower economic risk than Org2. With no organic price premiums, economic returns for corn and soybean in the organic systems were generally lower than those for the conventional systems due to lower grain yields in the organic systems. An exception to this pattern is that returns for corn in Org4+ were equal to or greater than those in NT in four of six years due to both lower production costs and greater revenue than for Org2 and Org3. With no organic premiums, present value of net returns for the full rotations was greatest for NT in 4 of 6 years and greatest for Org4+ the other 2 years, when returns for hay crops were high. Returns for individual crops and for full rotations were, in general, among the lowest and economic risk was, in general, among the highest for Org2 and Org3. Results indicte that Org4+, the longest and most diverse rotation, had the most stable economic returns among organic systems but that short-term returns could be greatest with Org2. This result likely explains, at least in part, why some organic farmers in the mid-Atlantic region, especially those recently converting to organic methods, have adopted this relatively short rotation. The greater stability of the longer rotation, by contrast, may explain why farmers who have used organic methods for longer periods of time tend to favor rotations that include perennial forages.
  • Authors:
    • Lal, R.
    • Chatterjee, A.
  • Source: Soil & Tillage Research
  • Volume: 104
  • Issue: 2
  • Year: 2009
  • Summary: No-tillage (NT) farming offers innumerable benefits to soil and water conservation, however, its potential to sequester soil organic carbon (SOC) and related soil properties varies widely. Thus, the impact of long-term (>4 yr) NT-based cropping systems on SOC sequestration and selected soil physical and chemical parameters were assessed across soils within five Major land Resource Areas (MLRAs: 99 and 111 in Michigan; 124 and 139 in Ohio; and 127 in Pennsylvania) in eastern U.S.A. Soil samples were collected from paired fields of NT and plow tillage (PT) based cropping systems and an adjacent woodlot (WL). The SOC concentration, bulk density (rho(b)), texture, pH, electrical conductivity (EC), soil N, coarse particulate organic matter (CPOM) C and N, and nitrate N (NO3-N) concentrations were determined. Conversion from NT to PT practice increased surface soil pH from 5.97,6.56 and 6.02 to 6.62, 6.91 and 7.09 under MLRAs 127, 111 and 99, respectively. NT soils had higher SOC concentration soils by 30,50 and 67% over PT soils at 0-5 cm depth under MLRAs 99, 111 and 127, respectively. Considering the whole soil profile SOC, WL had higher SOC pool than NT and PT practices under MLRAs 99, 111 and 124, however, there was no significant difference (P < 0.05) between NT and PT practices across five soils. Almost the same trend was observed in the case of depthwise soil N content. NT soil had higher N content than PT soils by 27,44 and 54% under MLRAs 99,127 and 111, respectively. However, whole soil profile N content of NT soil was significantly higher by 12% than PT soil under MLRA 99. Concentrations of CPOM associated C and N of NT soil was higher than PT soil under MLRAs 99. 111 and 127 at 0-5 soil depth. These results indicated that impact of tillage on soil C and associated soil quality parameters is confined within specific soil types. (C) 2009 Elsevier B.V. All rights reserved.
  • Authors:
    • Mishra, U.
    • Lal, R.
    • Christopher, S. F.
  • Source: Soil Science Society of America Journal
  • Volume: 73
  • Issue: 4
  • Year: 2009
  • Authors:
    • Mishra, U.
    • Lal, R.
    • Christopher, S. F.
  • Source: Soil Science Society of America Journal
  • Volume: 73
  • Issue: 1
  • Year: 2009
  • Summary: No-till (NT) agriculture has been promoted as one of the optimal management practices that preserves soil and water, and increases soil organic C (SOC) compared with conventional tillage (CT) practices. Information on SOC sequestration in NT systems, however, has been based on measurements from the surface soil (<30 cm) and little is known about the extent of SOC sequestration in NT across the entire 0- to 60-cm soil profile. We conducted a regional study of NT farming to assess the extent of SOC sequestration in the whole soil profile across 12 contrasting but representative soils in the Midwestern United States, each within a Major Land Resource Area (MLRA: 98, 111C, 114B, 122 in Indiana; 111A, 111B, 111D, 124, and 126 in Ohio; and 127 and 147 in Pennsylvania). Soils on gentle terrain were sampled in paired NT and CT fields as well as in an adjacent woodlot in each MLRA. The SOC and N concentrations were greater in the surface 0- to 5-cm soil in NT than CT in MLRA 124. The SOC concentration in CT soil was greater than in NT soil at 10 to 30 cm in MLRAs 98 and 126. The total SOC pool for the whole soil profile did not differ between NT and CT in eight of the 12 MLRAs and the total profile SOC was actually greater under CT in MLRAs 98, 127, and 126, resulting in negative C sequestration rates on conversion from CT to NT in these three MLRAs. This regional study suggests that the entire soil profile must be examined and ecosystem C budget assessed when elucidating SOC sequestration in NT vs. CT fields.