Submitted to: Soil Science Society of America Journal
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 6/9/2009
Publication Date: 1/8/2010
Citation: Archer, D.W., Halvorson, A.D. 2010. Greenhouse Gas Mitigation Economics for Irrigated Cropping Systems in Northeastern Colorado. Soil Sci. Soc. Am. J. 74(2):446-452.
Interpretive Summary: Soil and crop management practices could potentially reduce greenhouse gas emissions. However, producers will not use these practices if they are not profitable. Net returns and net greenhouse gas emissions were compared for conventional tillage continuous corn, no-till continuous corn, and a no-till corn-bean rotation for a range of nitrogen (N) fertilizer application rates. Results showed that net greenhouse gas emissions generally increased with higher N fertilizer application rates, with the exception of no-till continuous corn where net greenhouse gas emissions initially declined and then increased at higher N rates. Switching from conventional tillage to no-till could increase profitability and reduce net greenhouse gas emissions. The no-till corn-bean rotation had the highest net returns while the no-till continuous corn rotation had the lowest net greenhouse gas emissions when N fertilizer was applied to maximize profitability. These findings show that producers may be able to make some management changes that reduce greenhouse gas emissions without reducing profitability.
Technical Abstract: Recent soil and crop management technologies have potential for mitigating greenhouse gas emissions. However, these management strategies must be profitable if they are to be adopted by producers. The economic feasibility of reducing net greenhouse gas emissions in irrigated cropping systems was evaluated over 5-yr on a clay loam soil. Cropping systems included: conventional tillage continuous corn (Zea mays L.) (CT-CC), no-till continuous corn (NT-CC), and no-till corn-bean (NT-CB) rotation including either soybean [Glycine max (L.) Merr.] or dry bean [(Phaseolus vulgaris (L.)]. The study included six nitrogen fertilization rates ranging from 0 to 246 kg ha-1. Results showed highest average net returns for NT-CB followed by NT-CC and CT-CC. Net global warming potential (GWP) generally increased with increasing N fertilizer rate with the exception of NT-CC, where net GWP initially declined and then increased at higher N rates. Combining economic and net GWP measurements showed producers have an economic incentive to switch from CT-CC to NT-CB by increasing annual average net returns $228 ha-1 while reducing annual net GWP by 861 kg CO2 equivalents ha-1. However, the greatest GWP reductions (1397 kg CO2 equivalents ha-1) could be achieved by switching from CT-CC to NT-CC while also increasing net returns, but the presence of a more profitable NT-CB alternative is unlikely to be chosen without additional economic incentives.