Submitted to: Asian Crop Science Conference
Publication Type: Proceedings
Publication Acceptance Date: 9/20/1995
Publication Date: N/A
Technical Abstract: Rising CO2 concentrations from agricultural activities has prompted the need to quantify the flux of greenhouse gases to better understand the carbon and water flow dynamics within agricultural production systems. The effect of four tillage methods on the short-term CO2 and water vapor flux from a clay loam soil in the Northern Corn Belt of the U.S.A. was evaluated. The four tillage methods were moldboard plow only, moldboard plow plus disk harrow twice, disk harrow and chisel plow using standard tillage equipment following a wheat (T. Aestivum L) crop compared with no tillage. The CO2 flux was measured with a large portable chamber system commonly used to measure crop canopy gas exchange initiated within 5 minutes after tillage. Moldboard plow had the roughest soil surface and the highest initial CO2 flux and maintained the highest flux related to soil disturbance. Moldboard plow plus disking had the highest evaporation rate for the first three days after tillage. Evaporation rates decreased with drying after tillage and the differences in evaporation between tillage treatments were small but consistent after 64 mm of precipitation. Tillage methods with low soil disturbance resulted in lower evaporation rates and lower CO2 fluxes. Tillage methods affected the initial CO2 flux differently and suggested improved soil management can minimize agriculture's impact on the global CO2 increase.