• Authors:
    • Barker-Reid, F.
    • Gates, W. P.
    • Eckard, R. J.
    • Wilson, K.
    • Baigent, R.
    • Galbally, I. E.
    • Meyer, C. P.
    • Weeks, I. A.
  • Source: 4th International Symposium on non-CO2 Greenhouse Gases
  • Year: 2005
  • Authors:
    • R,Leuning
    • IE,Galbally
    • K,Kelly
    • R,Edis
    • Y,Li
    • D,Turner
    • D,Chen
  • Source: 4th International Symposium on non-CO2 Greenhouse Gases
  • Year: 2005
  • Authors:
    • Denmead, O.T.
    • Bryant, G.
    • Reilly, R.
    • Griffith, D. W. T.
    • White, I.
    • Stainlay, W.
    • Melville, M. D.
    • Macdonald, B. C. T.
  • Source: Proceedings of the Australian Society of Sugar Cane Technologists
  • Volume: 27
  • Year: 2005
  • Authors:
    • Kelly, K.
    • Baigent, R.
    • Eckard, R.
    • Weeks, I.
    • Leuning, R.
    • Phillips, F.
    • Barker-Reid, F.
    • Gates, W.
    • Grace, P.
    • Galbally, I.
    • Meyer, M.
    • Bentley, S.
  • Source: Environmental Sciences
  • Volume: 2
  • Issue: 2-3
  • Year: 2005
  • Authors:
    • Chan, K. Y.
    • Heenan, D. P.
  • Source: Soil Use and Management
  • Volume: 21
  • Issue: 4
  • Year: 2005
  • Authors:
    • Verchot, L.
    • Palm, C.
    • Albrecht, A.
    • Cadisch, G.
    • Mutuo, P.
  • Source: Nutrient Cycling in Agroecosystems
  • Volume: 71
  • Issue: 1
  • Year: 2005
  • Summary: Losses of carbon (C) stocks in terrestrial ecosystems and increasing concentrations of greenhouse gases in the atmosphere are challenges that scientists and policy makers have been facing in the recent past. Intensified agricultural practices lead to a reduction in ecosystem carbon stocks, mainly due to removal of aboveground biomass as harvest and loss of carbon as CO2 through burning and/or decomposition. Evidence is emerging that agroforestry systems are promising management practices to increase aboveground and soil C stocks and reduce soil degradation, as well as to mitigate greenhouse gas emissions. In the humid tropics, the potential of agroforestry (tree-based) systems to sequester C in vegetation can be over 70 Mg C ha-1, and up to 25 Mg ha-1 in the top 20 cm of soil. In degraded soils of the sub-humid tropics, improved fallow agroforestry practices have been found to increase top soil C stocks up to 1.6 Mg C ha-1 yr-1 above continuous maize cropping. Soil C accretion is linked to the structural development of the soil, in particular to increasing C in water stable aggregates (WSA). A review of agroforestry practices in the humid tropics showed that these systems were able to mitigate N2O and CO2 emissions from soils and increase the CH4 sink strength compared to cropping systems. The increase in N2O and CO2 emissions after addition of legume residues in improved fallow systems in the sub-humid tropics indicates the importance of using lower quality organic inputs and increasing nutrient use efficiency to derive more direct and indirect benefits from the system. In summary, these examples provide evidence of several pathways by which agroforestry systems can increase C sequestration and reduce greenhouse gas emissions.
  • Authors:
    • Paustian,Keith
    • Cole,C. Vernon
    • Sauerbeck,Dieter
    • Sampson,Neil
    • Peairs,F. B.
    • Bean,B.
    • Gossen,B. D.
  • Source: Agronomy Journal
  • Volume: 97
  • Issue: 2
  • Year: 2005
  • Summary: The intensification of traditional wheat (Triticum aestivum L.)-fallow production systems may have important consequences for management of insects, pathogens, and weeds in Great Plains dryland production systems. Assessment of these consequences is difficult due to the diversity of production systems, environmental conditions, and pests found in the region. Certain pest groups, such as weeds, traditionally controlled during the fallow period, may be favored by intensified cropping while others, such as those specializing on wheat, should be disadvantaged. Changes in pest and disease complexes will likely be evolutionary rather than revolutionary, as has been the case with other significant changes in production practices. Preventive practices in dryland production systems currently emphasize the control of grassy weeds while intensified systems may have less emphasis on the control of volunteer wheat. Crop rotation will remain a key avoidance strategy for pathogens and will help broaden herbicide options. Pest monitoring provides essential information on pest activity and environmental conditions and will become more complex as production systems are intensified. Important suppressive practices for dryland production systems include conservation biological control, tillage, and chemical controls. Chemical control, in particular, is expected to become more complicated due to drift concerns, rotational restrictions, the possible need for herbicide-tolerant crops, and the development of weed populations resistant to glyphosate. Pest management requirements should be considered during cropping system design and establishment.
  • Authors:
    • Traxler, G.
    • Qaim, M.
  • Source: Agricultural Economics
  • Volume: 32
  • Issue: 1
  • Year: 2005
  • Authors:
    • O'Neil, K.
    • Nyiraneza ,J.
    • Leep, R.
    • Black, J. R.
    • Mutch, D.
    • Labarta, R.
    • Swinton, S. M.
    • Snapp, S. S.
  • Source: Agronomy Journal
  • Volume: 97
  • Issue: 1
  • Year: 2005
  • Summary: The integration of cover crops into cropping systems brings costs and benefits, both internal and external to the farm. Benefits include promoting pest-suppression, soil and water quality, nutrient cycling efficiency, and cash crop productivity. Costs of adopting cover crops include increased direct costs, potentially reduced income if cover crops interfere with other attractive crops, slow soil warming, difficulties in predicting N mineralization, and production expenses. Cover crop benefits tend to be higher in irrigated systems. The literature is reviewed here along with Michigan farmer experience to evaluate promising cover crop species for four niches.
  • Authors:
    • Dell, C. J.
    • Venterea, R. T.
    • Sauer, T. J.
    • Allmaras, R. R.
    • Reicosky, D. C.
    • Johnson, J. M. F
  • Source: Soil & Tillage Research
  • Volume: 83
  • Issue: 1
  • Year: 2005
  • Summary: The central USA contains some of the most productive agricultural land of the world. Due to the high proportion of land area committed to crops and pasture in this region, the carbon (C) stored and greenhouse gas (GHG) emission due to agriculture represent a large percentage of the total for the USA. Our objective was to summarize potential soil organic C (SOC) sequestration and GHG emission from this region and identify how tillage and cropping system interact to modify these processes. Conservation tillage (CST), including no-tillage (NT), has become more widespread in the region abating erosion and loss of organic rich topsoil and sequestering SOC. The rate of SOC storage in NT compared to conventional tillage (CT) has been significant, but variable, averaging 0.40 ± 0.61 Mg C ha-1 year-1 (44 treatment pairs). Conversion of previous cropland to grass with the conservation reserve program increased SOC sequestration by 0.56 ± 0.60 Mg C ha-1 year-1 (five treatment pairs). The relatively few data on GHG emission from cropland and managed grazing land in the central USA suggests a need for more research to better understand the interactions of tillage, cropping system and fertilization on SOC sequestration and GHG emission.