培养条件下秸秆还田对水稻土微生物活性的影响

采用室内培养的方法,以秸秆不还田为对照,通过监测土壤可溶性有机碳(DOC)、矿质氮、微生物量碳(MBC)、微生物量氮(MBN)含量和主要微生物类群数量,研究了水稻秸秆直接还田(SF0)与氯仿熏蒸预处理后还田(SF1)稻田土壤微生物活性变化及其差异。结果表明,与对照相比,经过28 d恒温培养,秸秆还田处理(SF0和SF1)的土壤可溶性有机碳含量显著增加,矿质氮含量显著降低;SF0和SF1处理的土壤微生物量碳、氮含量与对照相比显著增加,而且微生物量氮对秸秆介入的响应更为敏感;与不还田相比,秸秆还田促进了土壤微生物的繁殖,SF0和SF1处理的土壤细菌、真菌和放线菌数量显著增加;SF0处理的土壤DOC含量、细菌和放线菌数量显著高于SF1处理,与秸秆直接还田相比,熏蒸预处理后还田的土壤微生物活性及秸秆腐解程度均显著降低。

Effect of Straw Incorporation on Paddy Soil Microorganism Activity under Incubation

A incubation experiment with no straw as control was carried out to investigate the effect of straw returning （SF0） and returning with chloroform fumigation （SFI） on paddy soil microorganism activity and its difference. The content of soil dissolved organic carbon （DOC）, mineral nitrogen, microbial biomass carbon （MBC）, microbial biomass nitrogen （MBN） and microorganism quantity were determined after incubation. The results showed as follows： （1）Compared with the control, the content of DOC with straw returning （SF0 and SFI ） increased significantly and the content of mineral nitrogen decreased significantly. （2）SF0 and SFI treatments increased MBC and MBN significantly compared to control and MBN was more sensitive to straw treatments. （3）Compared with the control, straw returning promoted the proliferation of microorganisms with a significantly increasement in bacteria, fungi and actinomycetes. （4）The content of DOC and the quantity of bacteria and actinomyeetes of SF0 treatment were significantly higher than SFI treatment. Compared with SF0, straw fumigated pretreatment reduced soil microorganism activity and straw maturity significantly.