Submitted to: ASA-CSSA-SSSA Annual Meeting Abstracts
Publication Type: Abstract Only
Publication Acceptance Date: 11/6/2005
Publication Date: 11/6/2005
Citation: Johnson, J.M., Reicosky, D.C., Venterea, R.T., Stott, D.E. 2005. Managing for mitigation of greenhouse gases and carbon sequestration in the Midwest [abstract][CD-ROM]. ASA-CSSA-SSSA Annual Meeting Abstracts. ASA-CSSA-SSSA Annual Meeting. Nov. 6-10, 2005, Salt Lake City, UT.
Technical Abstract: The central USA contains some of the most productive agricultural land in 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) emissions represent a large percentage of the total for US agriculture. 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. Soil C loss from intensive tillage has been related to the volume of soil disturbed in the tillage operation. 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 yr-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 yr-1 (five treatment pairs). In Minnesota, to date the largest nitrous oxide fluxes were measured following corn and alfalfa when the soil surface thawed in late winter, which resulted in saturated soil. There are limited data on GHG emission from cropland or managed grazing land, which is necessary to understand the interaction of tillage and fertilization on C sequestration and GHG emission offsets across the region.