|Allmaras, Raymond - USDA-ARS (RETIRED)|
Submitted to: ASA-CSSA-SSSA Annual Meeting Abstracts
Publication Type: Abstract Only
Publication Acceptance Date: November 4, 2004
Publication Date: November 4, 2004
Citation: Reicosky, D.C., Allmaras, R.R., Sauer, T.J., Venterea, R.T., Dell, C.J., Johnson, J.M. 2004. Greenhouse contributions and mitigation potential in central USA agricultural regions of North America [CD-ROM]. ASA-CSSA-SSSA Annual Meeting Abstracts. Madison, Wisconsin. Technical Abstract: The Central United States contains some of the world's most productive agricultural land. Due to the high proportion of land area committed to crop land or pasture in this region, the carbon (C) stored or greenhouse gas (GHG) emissions due to agriculture represent a large percentage of the US total. The objective of this work was to quantify potential C sequestration and GHG emission and how tillage and cropping systems interact to modify these processes. No till (NT) systems have increased in the region, reducing the loss of organic matter rich topsoil and sequestering C. The rates of C storage in NT compared to conventional tillage are highly variable; averaging 630 kg C ha**-1 y**-1 for 21 treatment (trt) pairs in the Central US, which exceeds the global average for a humid region. Converting from continuous corn to three or more crops in rotation increased soil organic C (SOC) an average 140 kg C**-1 y**-1 (15 trt pairs), but converting from continuous corn to corn-soybean rotation decreased SOC an average of 150 kg C ha**-1 y**-1 (7 trt pairs). An increase in N2O emissions of 2.1 kg N ha**-1 y**-1 would offset the sequestration of 300 kg C ha**-1 y**-1. Limited data on GHG emission from cropland or managed grazing land suggests the need to understand the interaction of tillage and fertilization on C sequestration and GHG emission offsets in cropland and managed grassland across the region.