不同保护性耕作措施对麦-豆轮作土壤有机碳库的影响

通过设置在甘肃省定西市李家堡镇的不同保护性耕作试验,对春小麦、豌豆两种轮作次序下的土壤总有机碳、活性有机碳、微生物量碳含量进行了测定,并计算了各处理土壤碳库管理指数.结果表明:经过5年的轮作后,与传统耕作相比,两种轮作次序下免耕秸秆覆盖和传统耕作结合秸秆还田处理均能不同程度地提高土壤总有机碳、活性有机碳、微生物量碳含量及土壤碳库管理指数,而免耕不覆盖处理除在0～5 cm提高了土壤有机碳库管理指数外,其他各层次均降低了土壤有机碳库管理指数,说明仅依靠免耕而不结合秸秆覆盖或还田对于土壤有机碳库的管理来讲是不可持续的.

Effects of different conservation tillage measures on soil organic carbon pool in two sequence rotation systems of spring wheat and pease

A 5-year conservation tillage experiment was conduced in Lijiabu, Dingxi City of Gansu Province to study the effects of crop rotation and tillage on soil total carbon, active organic carbon, microbial biomass carbon and soil organic carbon pool management index. The results show that conventional tillage with straw mulching and conventional tillage, in which straw is plowed into soil, increase soil organic carbon, active organic carbon, microbial biomass carbon and soil carbon pool management index under both rotation sequences. Though zero-tillage increases soil carbon pool management index in 0 ~5 cm soil layer, it decreases index of the other soil layers. The findings then suggest that zero-tillage without straw mulching or straw plowing into the soil is non-sustainable for soil organic carbon management.