土壤学报2017，Vol.54Issue(6)：1326-1331,6.DOI:10.11766/trxb201706010145
应重视硝态氮同化过程在降低土壤硝酸盐浓度中的作用
Role of Microbial Assimilation of Soil NO3- in Reducing Soil NO3- Concentration
摘要
Abstract
NO3- accumulation in the soil would trigger N losses through runoff,leaching and N2O emission. It is,therefore,of particular importance to take appropriate nitrogen(N)management strategies to reduce soil NO3- accumulation,and hence to enhance N use efficiency and reduce N losses to the environment. Application of nitrification inhibitor(NI)has been demonstrated to be effective in reducing soil NO3- concentration,NO3- leaching and N2O emission,and simultaneously increasing crop yield. However,there is an indisputable fact that NI application increases ammonia(NH3)emission and causes NI contamination. As a matter of fact,soil NO3- concentration varies with NO3- generation(nitrification)and consumption (assimilation)rates in aerobic conditions. Under the influence of the viewpoint that soil microbes prefer NH4+-N for their growth,it is commonly held that soil microbes rarely use NO3- in farmlands. Consequently, the study on processes of soil microbial NO3- assimilation has been neglected to a certain extent. The process of soil microbial NO3- assimilation is found to be unique in advantage. It turns NO3- into microbial biomass N for temporary storage before mineralization to be available to crops for a longer season or crops in the following season. There is no doubt that soil microbial NO3- immobilization is stimulated by specific extraneous C input, which deserves more attention in future studies concerning how to reduce soil NO3- accumulation. Further studies should primarily focus on the following several aspects:(1)to elucidate mechanism of the microbe driving NO3- assimilation under elevated C availability,(2)to explore how to control microbial assimilation and remineralization of NO3- to match soil N supply with crop N demand and reduce N losses,and(3) to explore how to avoid stimulating denitrification and associated N losses while enhancing microbial NO3- assimilation under the condition of sufficient C supply.关键词
硝态氮累积/硝态氮同化/硝化抑制剂/碳源Key words
NO3- accumulation/NO3- immobilization/Nitrification inhibitor/Carbon source分类
农业科技引用本文复制引用
程谊,黄蓉,余云飞,王慎强..应重视硝态氮同化过程在降低土壤硝酸盐浓度中的作用[J].土壤学报,2017,54(6):1326-1331,6.基金项目
国家自然科学基金项目(41671231,41571294)和国家重点研发计划项目(2017YFD0200106,2017YFD0800103)资助 Supported by the National Natural Science Foundation of China(Nos. 41671231and 41571294)and the National Key Research and Development Program of China(Nos. 2017YFD0200106 and 2017YFD0800103) （41671231,41571294）
