• Authors:
    • Grace, P.
    • Kiese, R.
    • Butterbach-Bahl, K.
    • Rowlings, D.
    • Rochester, I.
  • Source: Soil Solutions for a Changing World: proceedings of the 19th World Congress of Soil Science
  • Year: 2010
  • Authors:
    • Cammarano, D.
    • Rowlings, D.
    • Grace, P. R.
    • Scheer, C.
  • Source: Annual Meeting of the American Society of Agronomy, Crop Science Society of America, and Soil Science Society of America
  • Year: 2010
  • Authors:
    • Maraseni, T. N.
    • Cockfield, G.
    • Maroulis, J.
  • Source: The Journal of Agricultural Science
  • Volume: 148
  • Year: 2010
  • Authors:
    • Maraseni, T. N.
    • Cockfield, G.
    • Maroulis, J.
  • Source: Journal of Environmental Science and Health, Part B: Pesticides, Food Contaminants, and Agricultural Wastes
  • Volume: 45
  • Issue: 6
  • Year: 2010
  • Authors:
    • Yu Qiang
    • Wang Enli
    • Chen Chao
  • Source: Agricultural Water Management
  • Volume: 97
  • Issue: 8
  • Year: 2010
  • Summary: In the North China Plain (NCP), while irrigation using groundwater has maintained a high-level crop productivity of the wheat-maize double cropping systems, it has resulted in rapid depletion of groundwater table. For more efficient and sustainable utilization of the limited water resources, improved understanding of how crop productivity and water balance components respond to climate variations and irrigation is essential. This paper investigates such responses using a modelling approach. The farming systems model APSIM (Agricultural Production Systems Simulator) was first calibrated and validated using 3 years of experimental data. The validated model was then applied to simulate crop yield and field water balance of the wheat-maize rotation in the NCP. Simulated dryland crop yield ranged from 0 to 4.5 t ha -1 for wheat and 0 to 5.0 t ha -1 for maize. Increasing irrigation amount led to increased crop yield, but irrigation required to obtain maximum water productivity (WP) was much less than that required to obtain maximum crop yield. To meet crop water demand, a wide range of irrigation water supply would be needed due to the inter-annual climate variations. The range was simulated to be 140-420 mm for wheat, and 0-170 mm for maize. Such levels of irrigation applications could potentially lead to about 1.5 m year -1 decline in groundwater table when other sources of groundwater recharge were not considered. To achieve maximum WP, one, two and three irrigations (i.e., 70, 150 and 200 mm season -1) were recommended for wheat in wet, medium and dry seasons, respectively. For maize, one irrigation and two irrigations (i.e., 60 and 110 mm season -1) were recommended in medium and dry seasons, while no irrigation was needed in wet season.
  • Authors:
    • Halvorson, A. D.
    • Grosso, S. J. del
    • Alluvione, F.
  • Source: Soil Science Society of America Journal
  • Volume: 74
  • Issue: 2
  • Year: 2010
  • Summary: Nitrogen fertilization is essential for optimizing crop yields; however, it increases N 2O emissions. The study objective was to compare N 2O emissions resulting from application of commercially available enhanced-efficiency N fertilizers with emissions from conventional dry granular urea in irrigated cropping systems. Nitrous oxide emissions were monitored from corn ( Zea mays L.) based rotations receiving fertilizer rates of 246 kg N ha -1 when in corn, 56 kg N ha -1 when in dry bean ( Phaseolus vulgaris L.), and 157 kg N ha -1 when in barley ( Hordeum vulgare L. ssp. vulgare). Cropping systems included conventional-till continuous corn (CT-CC), no-till continuous corn (NT-CC), no-till corn-dry bean (NT-CDb), and no-till corn-barley (NT-CB). In the NT-CC and CT-CC systems, a controlled-release, polymer-coated urea (ESN) and dry granular urea were compared. In the NT-CDb and NT-CB rotations, a stabilized urea source (SuperU) was compared with urea. Nitrous oxide fluxes were measured during two growing seasons using static, vented chambers and a gas chromatograph analyzer. Cumulative growing season N 2O emissions from urea and ESN application were not different under CT-CC, but ESN reduced N 2O emissions 49% compared with urea under NT-CC. Compared with urea, SuperU reduced N 2O emissions by 27% in dry bean and 54% in corn in the NT-CDb rotation and by 19% in barley and 51% in corn in the NT-CB rotation. This work shows that the use of no-till and enhanced-efficiency N fertilizers can potentially reduce N 2O emissions from irrigated systems.
  • Authors:
    • Kimble, J. M.
    • Follett, R. F.
    • Qian, Y.
  • Source: Soil Science Society of America Journal
  • Volume: 74
  • Issue: 2
  • Year: 2010
  • Summary: Turfgrass is a major vegetation type in the urban and suburban environment. Management practices such as species selection, irrigation, and mowing may affect C input and storage in these systems. Research was conducted to determine the rate of soil organic C (SOC) changes, soil C sequestration, and SOC decomposition of fine fescue (Festuca spp.) (rainfed and irrigated), Kentucky bluegrass (Poa pratensis L.) (irrigated), and creeping bentgrass (Agrostis palustris Huds.) (irrigated) using C isotope techniques. We found that 4 yr after establishment, about 17 to 24% of SOC at 0 to 10 cm and 1 to 13% from 10 to 20 cm was derived from turfgrass. Irrigated fine fescue added the most SOC (3.35 Mg C ha-1 yr-1) to the 0- to 20-cm soil profile but also had the highest rate of SOC decomposition (2.61 Mg C ha-1 yr-1). The corresponding additions and decomposition rates for unirrigated fine fescue, Kentucky bluegrass, and creeping bentgrass in the top 20-cm soil profile were 1.39 and 0.87, 2.05 and 1.73, and 2.28 and 1.50 Mg C ha-1 yr-1, respectively. Irrigation increased both SOC input and decomposition. We found that all turfgrasses exhibited significant C sequestration (0.32-0.78 Mg ha-1 yr-1) during the first 4 yr after turf establishment. The net C sequestration rate was higher, however, for irrigated fine fescue and creeping bentgrass than for Kentucky bluegrass. To evaluate total C balance, additional work is needed to evaluate the total C budget and fluxes of the other greenhouse gases in turfgrass systems.
  • Authors:
    • Bertrand, N.
    • Parent, L. É.
    • MacDonald, J. D.
    • Chantigny, M. H.
    • Angers, D. A.
    • Fallon, E.
    • Tremblay, N.
    • Rochette, P.
  • Source: European Journal of Soil Science
  • Volume: 61
  • Issue: 2
  • Year: 2010
  • Summary: Drainage and cultivation of organic soils often result in large nitrous oxide (N2O) emissions. The objective of this study was to assess the impacts of nitrogen (N) fertilizer on N2O emissions from a cultivated organic soil located south of Montreal, QC, Canada, drained in 1930 and used since then for vegetable production. Fluxes of N2O were measured weekly from May 2004 to November 2005 when snow cover was absent in irrigated and non-irrigated plots receiving 0, 100 or 150 kg N ha(-1) as NH4NO3. Soil mineral N content, gas concentrations, temperature, water table height and water content were also measured to help explain variations in N2O emissions. Annual emissions during the experiment were large, ranging from 3.6 to 40.2 kg N2O-N ha(-1) year(-1). The N2O emissions were decreased by N fertilizer addition in the non-irrigated site but not in the irrigated site. The absence of a positive influence of soil mineral N content on N2O emissions was probably in part because up to 571 kg N ha(-1) were mineralized during the snow-free season. Emissions of N2O were positively correlated to soil CO2 emissions and to variables associated with the extent of soil aeration such as soil oxygen concentration, precipitation and soil water table height, thereby indicating that soil moisture/aeration and carbon bioavailability were the main controls of N2O emission. The large N2O emissions observed in this study indicate that drained cultivated organic soils in eastern Canada have a potential for N2O-N losses similar to, or greater than, organic soils located in northern Europe.
  • Authors:
    • Horwath, W. R.
    • Rolston, D. E.
    • Kallenbach, C. M.
  • Source: Agriculture, Ecosystems & Environment
  • Volume: 137
  • Issue: 3
  • Year: 2010
  • Summary: Agricultural management practices such as subsurface drip irrigation (SDI) and winter legume cover cropping (WLCC) influence soil water dynamics as well as carbon and nitrogen cycling, potentially changing emission rates of soil CO2 and N2), principal greenhouse gases. A split plot tomato field trial in California's Central Valley was used to evaluate the use of SDI and WLCC on event-based CO2 and N2O emissions. SDI and WLCC were compared to the region's more conventional practices: furrow irrigation (FI) and no cover crop (NCC). Our results indicate that SDI offers the potential to manage cover crops without the significant increases in greenhouse gas production during the growing season as seen under FI cover-cropped systems. The highest N2O emissions occurred during the beginning of the rainy season in November in the FI-WLCC treatment(5 mg m-2 h-1) and the lowest in August in the SDI-NCC treatments (4.87 [micro]g m-2 h-1). CO2 emissions under WLCC were 40% and 15% greater compared to NCC under FI and SDI, respectively. The treatment with the greatest effect on CO2 and N2O emissions was WLCC, which increased average growing season N2O and CO2 emissions under FI by 60 [micro]g N2O m-2 h-1 and 425 mg CO2 m-2 h-1 compared to NCC. In SDI there was no effect of a cover crop on growing season CO2 and N2O emissions. In the rainy season, however, SDI N2O and CO2 emissions were not different from FI. In the rainy season, the cover crop increased N2O emissions in SDI only and increased CO2 emissions only under FI. Subsurface drip shows promise in reducing overall N2O emissions in crop rotations with legume cover crops.
  • Authors:
    • Yang, Z.
    • Chen, D.
    • Li, M.
    • Liang, W.
    • Wang, K.
    • Wang, Y.
    • Han, S.
    • Zhou, Z.
    • Zheng, X.
    • Liu, C.
  • Source: Plant and Soil
  • Volume: 332
  • Issue: 1-2
  • Year: 2010
  • Summary: Cotton is one of the major crops worldwide and delivers fibers to textile industries across the globe. Its cultivation requires high nitrogen (N) input and additionally irrigation, and the combination of both has the potential to trigger high emissions of nitrous oxide (N2O) and nitric oxide (NO), thereby contributing to rising levels of greenhouse gases in the atmosphere. Using an automated static chamber measuring system, we monitored in high temporal resolution N2O and NO fluxes in an irrigated cotton field in Northern China, between January 1st and December 31st 2008. Mean daily fluxes varied between 5.8 to 373.0 µg N2O-N m-2 h-1 and -3.7 to 135.7 µg NO-N m-2 h-1, corresponding to an annual emission of 2.6 and 0.8 kg N ha-1 yr-1 for N2O and NO, respectively. The highest emissions of both gases were observed directly after the N fertilization and lasted approximately 1 month. During this time period, the emission was 0.85 and 0.22 kg N ha-1 for N2O and NO, respectively, and was responsible for 32.3% and 29.0% of the annual total N2O and NO loss. Soil temperature, moisture and mineral N content significantly affected the emissions of both gases (p<0.01). Direct emission factors were estimated to be 0.95% (N2O) and 0.24% (NO). We also analyzed the effects of sampling time and frequency on the estimations of annual cumulative N2O and NO emissions and found that low frequency measurements produced annual estimates which differed widely from those that were based on continuous measurements.