控释氮肥对稻田土壤微生物的影响及其与土壤氮素肥力的关系

通过农业部望城红壤水稻土生态环境重点野外观测试验基地的短期控释氮肥试验,研究了控释氮肥对土壤微生物种群和生理群落的影响及其与土壤氮素肥力的关系.结果表明,短期施用控释氮肥稻田土壤的细菌、真菌和放线菌数量明显高于不施氮处理;土壤好氧自生固氮菌、氨化细菌、反硝化细菌的数量比尿素处理低;周年土壤细菌、放线菌数量明显高于尿素处理,真菌数量略低于尿素处理.50%控释氮肥配施有机肥处理土壤中细菌、真菌、放线菌的数量,明显高于尿素和单施控释氮肥处理.控释氮肥配施有机肥,土壤好氧自生固氮菌、氨化细菌、硝化细菌、反硝化细菌的数量均高于控释氮肥和70%控释氮肥处理.施氮处理土壤的好氧和厌氧自生固氮菌的数量低于不施氮处理.土壤中大多数微生物数量与土壤氮素养分含量呈正相关.

Effect of controlled release nitrogen fertilizer on soil microbe as well as its relation to soil nitrogen fertility

A field experiment was conducted,in monitoring experiment station for reddish paddy soil eco-environment in Wangcheng county,to study the short-term effects of controlled release nitrogen fertilizer (CRNF) on soil microbial populations and physiological functional microbe group,as well as their relationship to soil nitrogen fertility.Results showed that the amounts of bacteria,fungi and actinomycetes in paddy soil in CRNF treatment were higher than those in CK treatment.The amounts of bacteria and actinomycetes in CRNF treatment were increased,but slightly lower than that of fungi in urea treatment. Combined application of 50%CRNF with organic manure (Sewage sludge) increased bacteria,fungi and actinomycetes in soil as compared with treatment CRNF or urea.The amounts of aerobic and anaerobic azotobacteria were lower in fertilizer treatments than that in CK treatment.The amounts of aerohic azotobacteria,ammonifiers and anti-nitrifiers were lower in CRNF application than those in urea application.The amounts of aerohic azotobacteria,ammonifiers,nitrifiers and anti-nitrifiers were higher in combined application, 50%CRNF with organic manure,than that in CRNF and that in 70% CRNF.There was a positive correlation between the amounts of most soil microbe and soil nitrogen content.