少免耕栽培晚稻对土壤微生物区系及活度的动态影响

为探明农业技术措施对土壤生物学特征的影响，以制定合理的耕作制度，保障土壤的可持续利用，进行了1／3稻草覆盖少免耕对晚稻土壤微生物区系及活度的动态影响研究．结果表明，土壤中几类微生物的数量在晚稻不同生育期都表现为先升后降的趋势，并且在晚稻分蘖盛期最高．好气性细菌、放线菌、真菌及微生物活度从高到低为少耕土壤、翻耕土壤、免耕土壤，而厌气性细菌数量从高到低为翻耕土壤、少耕土壤、免耕土壤．通过对土壤微生物分析评价发现，在提高土壤质量和利于作物生长方面，少量秸秆还田少耕要优于少壤特秆还田翻耕和免耕。

Effects of No Tillage or Minimum Tillage or Trend of Microbial Flora and Its Activity in Paddy Soil

In order to probe into the effect of agricultural technology on biological character in soil and provide scientific proof for reasonable culturing system,the studies on effect of no tillage or minimum tillage on the microbial flora and its activity in paddy soil covered with 1/3 straw were conducted.The results showed that:When the microbial character was analysed at early-rice-harvested stage,late-rice maximum tillering stage,late-rice maximum booting stage and late-rice-harvested stage,the quantities of the main groups of microbes and microbial activities in soil at late-rice maximum tillering stage were the most.The quantities of aerobic bacteria,actinomycetes and fungi in soil were minimum tillage>tillage>no tillage.The quantities of anaerobic bacteria in soil were tillage>minimum tillage> no tillage.The proof could be provided by the microbial results that minimum tillage with minimum straw was a better technology to improve soil quality and do good to crops than tillage or no tillage.