Carbon Dioxide Emissions after Application of Different Tillage Systems for Loam in Northern China

摘要

Tillage operations influence soil physical properties and crop growth and thus both directly and indirectly the cropland CO<,2> exchange with the atmosphere. In this study, the results CO<,2> flux measurements on cropland under different tillage practices in northern China are presented. CO<,2> flux on croplands with a winter wheat (Triticum aestivum L.) and maize (Zea may L.) rotation was monitored on plots with conventional tillage (CT), rotary tillage (RT) and no tillage (NT). Soil CO<,2> flux was generally greater in CT than in NT and the RT CO<,2> flux was only slightly smaller than the CT. Daily soil flux for CT, RT, and NT averaged 11.30g CO<,2> m-2 d-1, 9.63g CO<,2> m-2 d-1 and 7.99g CO<,2> m<'-2> d<'-1>, respectively, during the growing period. Analysis of variance shows that these differences are significant for the three tillage treatments. Peak CO <,2> emissions were recorded on the CT and RT croplands after tillage operation, demonstrating that the tillage operations result in a rapid physical release of CO<,2>. At the same time, no obviously increased emission of CO<,2> occurred on the NT plot due to no tillage operation.