保护性耕作对土壤微生物特性及酶活性的影响

大田试验研究了保护性耕作对土壤微生物量、活跃微生物量、土壤呼吸、呼吸商、土壤酶的影响。结果表明，秸秆还田能够显著提高土壤微生物量碳和活跃微生物量，深松耕还田能显著提高土壤活跃微生物量。随耕作作业之后时间的推迟，活跃生物量减小。秸秆还田初期（小麦越冬期）能显著提高土壤呼吸作用，提高99．7％；后期（小麦播种期）能显著降低土壤呼吸，降低16．6％。随耕作作业之后时间的推迟，秸秆还田和保护性耕作都会减少农田向大气中CO2的排放，减少土壤碳库的亏损。深松耕还田显著提高土壤脲酶、蔗糖酶活性。土壤呼吸和土壤活跃微生物量是衡量土壤微生物特性和土壤酶的较好指标。

Effects of Conservati on Tillageon Soil Microbial Characters and Soil Enzyme Activities

Effects of conservation tillage on soil microbiomass,active soil microbiomass,respiration quotien,and enzyme activities were studied by field experiment.Results showed that straw returning could significantly increase soil microbial biomass and active microbiomass.Subsoiling with straw returning could siginificantly active microbiomass.The longer time after tilth,the smaller active soil microbiomass.Straw returning could increase soil respiration by 99.7% in the earlier stage(over-wintering stage) and reduce soil respiration by 16.6% in the later stage(seeding-sprouting stage).Compared with conventional tillage with no straw returning,conservation tillage could increase soil respiration in the earlier stage after tillage and reduce soil respiration in the later stage and reduce the loss of soil carbon,of which rotary tillage with straw returning was the best.Subsoiling returning could significantly increase soil urease activity and sucrase activity.Soil respiration and active microbiomass were good indexes of soil microbial characters and soil enzyme.