施用有机肥对植烟土壤氮素转化与功能微生物的影响

Effects of Applying Organic Manure on Nitrogen Transformation and Functional Microbes of Tobacco-planting Soil

为探明植烟土壤有机肥氮素的分解规律,采用田间根区取样的方式,在等氮量(有机氮占20%)条件下,研究牛粪、秸秆、油枯有机肥与化肥配施对植烟土壤氮素转化及相关功能菌的影响。结果表明:有机肥与化肥配施氮素转化的相关微生物数量、氮素含量较单施化肥的土壤有不同程度升高。氨化菌、亚硝化菌、反硝化细菌和好氧性自生固氮菌种在烟草旺长期以及成熟期明显增高,之后降低较快,与土壤中的有机质、氮素含量呈明显的正相关。牛粪、油枯处理在烟草生长伸根期及旺长期氨化菌数量增加较快,有利于有机氮素分解,同时反硝化菌数量增长缓慢,降低了无机态氮素的分解。施秸秆前应调节碳氮比后再施入土壤,以促进秸秆中有机态氮素的分解。

The effect of applying different combinations of organic manures and chemical fertilizer on nitrogen transformation and related functional bacteria in tobacco-planting soil was studied under the equal nitrogen amount（20 % organic nitrogen） by the field sampling method to explore the nitrogen decomposition rule in organic manure of tobacco-planting soil. Results： The microbial quantity and nitrogen content related to nitrogen transformation in tobacco-planting soil applied with different combinations of organic manures and chemical fertilizer is higher than CK（single applying chemical fertilizer） to varying degrees. Ammonifiers,nitrosobacteria,denitrifying bacteria and aerobiotic azotobacteria in soil increase obviously at vigorous growing stage and maturity stage of tobacco. There are the positive correlations between four kinds of bacteria and soil organic matter,soil nitrogen content. The ammonifier quantity of tobacco-planting soil applied with cow dung and oil cake increases rapidly at root extending stage and vigorous growing stage of tobacco,which benefits decomposition of organic nitrogen and decreases decomposition of inorganic nitrogen because of slow increase of denitrifying bacteria quantity. The carbon-nitrogen ratio of straw should be adjusted before applying straw into soil to promote decomposition of organic nitrogen in straw.