保护性耕作对黄土高原小麦田土壤微生物量碳的影响

Effects of conservation tillage practices on soil microbial biomass carbon in wheat field in the Loess Plateau

用氯仿熏蒸提取法测定了不同耕作处理(传统耕作、传统耕作+秸秆覆盖、免耕、免耕+秸秆覆盖)下小麦田的土壤微生物量碳,并探讨了其与土壤有机碳、全氮、小麦产量之间的关系,结果表明,水土保持耕作第三年较传统耕作可以有效地增加小麦田土壤微生物量碳。较之土壤有机碳、全氮、小麦产量,土壤微生物量碳对土壤肥力变化反应迅速。

Effects of different tillage practices on soil microbial biomass carbon in wheat field were carried out at the Loess Plateau experimental site of Lanzhou University. Soil microbial biomass C in different tillage practices： T （conventional tillage）, TS （conventional tillage with stubble retention）, NT （no-tillage with stubble retention）and NTS （no-tillage with stubble retention） were measured by chloroform fumigation extraction method,and the corelation between soil microbial biomass C, soil organic carbon and total nitrogen were also discussed. The results showed that soil microbial biomass C for conservation tillage practices was significantly higher than conventional tillage and microbial biomass C responded more rapidly than soil organic carbon and total nitrogen and wheat production to soil fertility change. Therefore it is more sensitive indicators of changes in soil quality.