旱作条件下免耕对土壤微生物量碳、氮、磷的影响

Effects of No-tillage on Soil Microbial Biomass C,N and P in Rain-fed Agriculture

在干旱半干旱的定西市安定区李家堡镇设计田间定位试验,运用氯仿熏蒸浸提法测定土壤微生物量碳、氮和磷,研究免耕对土壤微生物量的影响。结果表明:免耕能提高表层土壤微生物生物量,免耕配合秸秆覆盖相比传统耕作在表层土壤中土壤微生物量碳增加了78.4%,土壤微生物量氮增加了89.6%,土壤微生物量磷增加了29.6%,免耕的生物活性主要表现在耕层。

The effects of no-tillage on soil microbial biomass C,N and P （SMBC, SMBN and SMBP） was studied in this paper through the trial designed in Lijiabu county, Anding, Dingxi, Gansu province,in which the method to measure soil microbial biomass is Chloroform Fumigation. The experiment results showed that no-tillage leads to an increase in mierobial biomass near the soil surface. Compared with conventional tillage with no straw, SMBC has increased 78.4%, SMBN has increased 89.6%, SMBP has increased 29.6% in 0-5 cm soil layer in the no-till with straw cover. The biological activity of no-till is only reflected in cultivation tier.