Submitted to: Book Chapter
Publication Type: Book / Chapter
Publication Acceptance Date: May 2, 2011
Publication Date: June 15, 2012
Citation: Hatfield, J.L., Parkin, T.B., Sauer, T.J., Prueger, J.H. 2012. Mitigation opportunities from land management practices in a warming world: Increasing potential sinks. In: Liebig, M.A., Franzluebbers, A.T., and Follett, R.F., editors. Managing Agricultural Greenhouse Gases. London, England: Academic Press. p. 487-504.
Climate change will create changes in CO2, temperature, and precipitation in the environment that plants will grow in throughout the world. The changes will not be uniform in time or space, creating further uncertainty about the magnitude of the impact of climate change on agricultural systems. Increases in CO2 will enhance plant growth; however, these increases will be offset by increased potential for heat stress and increased soil water use leading to potential water deficits. Emissions of CO2 and N2O from agricultural systems represent components of the C and N cycles. Mitigation of CO2 occurs when C captured by plants is retained in the soil and there is a potential of reduced emissions with conversion to no-tillage and crops with increased root biomass. Variations in observed CO2 are closely related to soil temperatures, thus increasing global temperatures may stimulate soil heterotrophic processes and increase soil organic carbon decomposition. Conversely, N2O emissions are more closely linked to soil water dynamics and, under changing climate, variations in soil water are expected to increase. Mitigation of N2O will result from improved N management, including changing rates, forms, and timing. Use of nitrification inhibitors can reduce N2O emissions; however, the impact is dependent upon the soil water regime and changing precipitation patterns will reduce the reliability of this practice. To achieve effective mitigation in CO2 or N2O will require understanding how the processes affecting emissions are affected by climate change and adopting management practices to incorporate this knowledge.