Submitted to: ASA-CSSA-SSSA Annual Meeting Abstracts
Publication Type: Abstract Only
Publication Acceptance Date: 8/1/2007
Publication Date: 11/5/2007
Citation: Cavigelli, M.A., Green, V.S., Rasmann, C., Djurickovic, M. 2007. Soils research at the long-term usda-ars farming systems project in beltsville, maryland [abstract]. ASA-CSSA-SSSA Annual Meeting Abstracts.
Technical Abstract: The USDA-ARS Beltsville Farming Systems Project (FSP) is a long-term cropping systems trial established in Maryland in 1996 to evaluate the sustainability of organic and conventional grain-based cropping systems. The five FSP cropping systems include a two-year organic corn (C)-soybean (S) rotation (Org2), a three-year C-S-wheat (W) rotation (Org3), a four-to-six year organic C-S-W-hay rotation (Org4+), and two three-year conventional C-S-W/S rotations, one no-till (NT) and one chisel-tilled (CT). The site is on Coastal Plain soils of the mid-Atlantic region and is one of only two long-term projects in the United States comparing organic, conventional till and no-till systems. Initial evaluations of the impact of management on soil sustainability focused on the three, three-year rotations. Among these systems, soil physical properties in the 0-5 cm depth were distinct for NT while Org3 and CT exhibited similar properties. Bulk density was 1.37 Mg m-3 in NT and 1.53 Mg m-3 in CT and Org3. Mean weight diameter of soil aggregates was 0.74 mm in NT and 0.40 mm in CT and Org3. Macro-aggregates represented 62 per cent of aggregates in NT but only 31 to 35 per cent in CT and Org3. Results show greater soil quality in NT than in CT and Org3. Results also show that despite greater tillage in Org3 than in CT, surface soil quality was not lower in Org3 than in CT, likely because of greater C inputs in Org3 than in CT. Initial greenhouse gas (CO2 and N2O) flux results show slightly greater cumulative annual CO2 flux in Org3 than in NT and lower cumulative N2O flux in Org3 than in NT. High intra- and inter-annual variability in gas fluxes, however, indicate the need to monitor fluxes over the long-term to ensure accurate estimates of system impacts. Taken together, results for the three-year crop rotations suggest there may be trade-offs in the soil sustainability benefits achieved using diverse cropping systems. We will also present results comparing total soil carbon and nitrogen to 1 m depth in the diverse FSP cropping systems after 12 years of cropping. Future research will focus on comparing soil quality among the three organic systems.