To evaluate the contribution of agriculture to climate change, the flux of greenhouse gases from different cropping systems must be assessed. Soil greenhouse gas flux (CO2, N2O, and CH4) was assessed during the final growing season in a long-term (10-year) study evaluating the effects of crop management (conservation and conventional) and atmospheric CO2 (ambient and twice ambient) on a Decatur silt loam (clayey, kaolinitic, thermic Rhodic Paleudults). Seasonal soil CO2 flux was significantly greater under elevated (4.39 Mg CO2-C ha -1) versus ambient CO2 (3.34 Mg CO2-C ha -1) and was generally greater in the conventional (4.19 Mg CO 2-C ha-1) compared with the conservation (3.53 Mg CO 2-C ha-1) system. Soil flux of both N2O (range, -1.5 to 53.4 g N2O-N ha-1 day-1) and CH 4 (range, -7.9 to 24.4 g CH4-C ha-1 day -1) were low throughout the study and rarely exhibited differences caused by treatments. Global warming potential (calculated based on flux of individual gases) was increased by elevated CO2 (33.4%) and by conventional management (17.1%); these increases were driven primarily by soil CO2 flux. As atmospheric CO2 continues to rise, our results suggest adoption of conservation management systems represents a viable means of reducing agriculture's potential contribution to global climate change.
|Original language||English (US)|
|Number of pages||8|
|State||Published - Jul 2010|
Copyright 2010 Elsevier B.V., All rights reserved.
- Carbon dioxide
- global change
- greenhouse gases
- nitrous oxide