铁作用下土壤氮素化学转化过程的研究进展

Chemical transformation of soil nitrogen under the influence of iron:A review

土壤中氮素的转化过程是氮素生物地球化学循环的关键环节,与当前诸多生态环境问题密切相关。传统观点认为土壤氮素转化过程须在微生物的参与下完成,但越来越多的研究发现化学过程同样发挥着重要的作用。目前相关研究多以铁作为氮素化学转化过程的电子供体或受体,并按照氮素的电子得失与去向将其划分为化学反硝化、化学硝化和化学固定过程。本研究以铁-氮之间氧化还原的耦合过程为基础对土壤中氮素化学转化的相关研究进行综合评述,着重探讨了土壤pH、固相界面、有机物浓度以及氮素水平等因素对该过程的影响机制。在此基础上,对相关工作提出建议与展望以供后续研究参考。

Nitrogen transformations in soil,closely related to cascades of ecological environment issues,have been regarded as the key compartment in nitrogen biogeochemical cycle.Most current researches have addressed the significance of microbial processes,while increasing evidences have shown that chemical processes also play important roles in soil nitrogen transformations.Chemical nitrogen transformations are widely presumed to be coupled with the redox of iron(Fe),and classified as chemical denitrification,chemical nitrification and chemical immobilization according to the electron transportation and nitrogen fates.In this paper,a review of recent literatures on chemical nitrogen transformations is carried out,based on the redox coupling between the iron and nitrogen cycles.Major influencing factors,such as soil pH,soil interface,organic matter and nitrogen level,are discussed in details.Some prospects are also proposed and highlighted for the related studies in the future.