热胁迫后施用氮肥和秸秆对土壤微生物生物量及功能的影响

Effects of nitrogen fertilization and straw amendment on soil microbial biomass and soil functions after heat stress

研究了热胁迫(40℃,18h)后在60d培养期内不施物料(S)、仅施尿素(N)、仅施秸秆(R)和二者配施(RN)处理下土壤微生物生物量及土壤功能(基础呼吸、基质诱导呼吸、秸秆分解能力)的变化.结果表明:热胁迫有促进土壤微生物生物量及功能的趋势,但其影响弱且持续时间短.不论热胁迫与否,与不施物料和仅施氮肥处理相比,施用秸秆及其与氮肥配施处理下土壤微生物生物量、基础呼吸、基质诱导呼吸和秸秆分解能力均大幅提高,而单施氮肥处理与不施物料处理相比变化不明显,各项指标甚至有降低趋势.表明施用秸秆及其与氮肥配施对自然土壤和环境胁迫(干扰)后土壤功能都有改善作用.

A 60-day incubation experiment was conducted to study the effects of nitrogen fertilization（N）,rice straw amendment（R）,and their combination（RN） on the changes of soil microbial biomass and soil functions（basal respiration,substrate-induced respiration,and straw decomposition） after heat stress（40 ℃ for 18 h）.Heat stress tended to promote the soil microbial biomass and soil functions,but the effects were weak and transient.Either with or without heating,treatment R and especially RN could greatly stimulate soil microbial biomass,basal respiration,substrate-induced respiration and straw decomposition,as compared to no straw amendment and with nitrogen fertilization alone,but the parameters in treatment N had less change,and even,presented a decreasing trend.It was suggested that straw amendment and its combination with nitrogen fertilization could improve soil functions in natural conditions or after environmental stress.