Submitted to: ASA-CSSA-SSSA Annual Meeting Abstracts
Publication Type: Abstract Only
Publication Acceptance Date: November 8, 2007
Publication Date: November 8, 2007
Citation: Reicosky, D.C., Baker, J.M., Ochsner, T.E., Lachnicht Weyers, S.L. 2007. Liquid manure injection and tillage effects on carbon dioxide and water fluxes using eddy covariance techniques [abstract][CD-ROM]. ASA-CSSA-SSSA Annual Meeting Abstracts. ASA-CSSA-SSSA Annual Meeting. Nov. 4-8, 2007, New Orleans, LA. Technical Abstract: Limited data on greenhouse gas (GHG) emission from cropland suggest the need to understand the interaction of tillage, manure and conventional fertilization on carbon (C) sequestration and GHG emission from cropland. The objective of this work is to quantify GHG emission affected by tillage and liquid manure application using eddy covariance techniques in a corn-soybean rotation. Two adjacent fields (32.4 ha each), one with manure and the other with fertilizer, on similar soil types were instrumented with eddy covariance towers. The first dry cattle manure application was October 17, 2003, on corn stalks and moldboard plowed on October 20. Both corn (2005) and soybean (2006) were planted at the normal times for this area. The net cumulative C flux in 2005 was higher on the manure treatment than the fertilizer treatment. The net accumulated C flux for corn in 2005 was considerably larger than that for soybean in 2006, related to crop biomass. As of October 4, 2006 (harvest date), the net cumulative C flux was 24.4 g C m-2 higher on the manure treatment compared to the fertilizer treatment. The extreme drought (74 mm rain in 64 days) starting after June 25 caused both fields to show stress symptoms and the data indicated the manure treatment evapotranspiration (ET) was 43 mm higher than the non-manure treatment at harvest. After soybean harvest, the manure system received an additional 149,600 l ha-1 of dairy manure incorporated on October 14, 2006. For the first 10 days after the liquid manure application, the manure treatment exhibited 21 g C m-2 more loss than the non-disturbed conventional fertilizer treatment. Short-term tillage effects showed flux increases that were subtle, but realistic based on soil temperature and water conditions. The annual C budget for conservation tillage systems demonstrates soil C loss from year round emissions.