可溶性有机氮(SON)是土壤氮素组成中最活跃的组分之一,在陆地生态系统氮循环及养分平衡方面起着重要作用。研究证明,SON既能通过矿化作用转化为矿质氮,也能被植物直接吸收利用。另外,SON流失可能会造成水生生态系统的富营养化,并加剧土壤系统温室气体N_2O的排放。因此,土壤SON受到国内外多学科的广泛关注。本文概述了SON的来源、组成、提取、测试、生态功能及其流失的环境效应,并指出未来有待深入研究的问题,以期为植物吸收利用氮素及生态系统氮循环的研究提供参考依据。 Soluble organic nitrogen (SON) is one of the most active components of soil nitrogen composition and plays an important role in the nitrogen cycle and nutrient balance of terrestrial ecosystems. Studies have shown that SON can be transformed into mineral nitrogen through mineralization, but also can be directly absorbed by plants. In addition, the loss of SON may cause the eutrophication of aquatic ecosystems and exacerbate the emission of greenhouse gas N 2 O in soil systems. Therefore, soil SON is widely concerned by many disciplines at home and abroad. This paper summarizes the origin, composition, extraction, testing, ecological functions and the environmental effects of loss of SON, and points out the issues that need to be further studied in the future in order to provide a reference for the plant to use nitrogen and ecosystem nitrogen cycle.