农田土壤氧化亚氮产生机制和相关模型研究进展

Research Development on Generation Mechanism and Related Models of N2O Emissions From Agricultural Soil

氧化亚氮(N2O)作为一种重要的温室气体,在大气中浓度不断上升,对环境的潜在破坏性也逐渐加强。农田土壤是N2O的重要产生源,其排放量约占全球N2O排放总量的70%。土壤中硝化、反硝化、硝化微生物反硝化和硝态氮异化还原成铵等作用是N2O生成的主要过程。在阐述土壤N2O产生机制的基础上,详述了预测农田土壤N2O排放模型如DNDC、WNMM、DAYCENT和Ecosys等机制过程模型模拟农田土壤N2O排放的机制及在相关研究中所取得的最新成果;并就农田土壤N2O排放模型的未来研究重点和方向进行探讨和展望,认为当前模型在机制和参数选择等方面仍有待改进并应更广泛地用于区域模拟。研究农田N2O产生机制并发展相应模型,对于预测、减少农田N2O排放,维护生态平衡等都具有十分重要的科学意义。

Nitrous oxide(N2O)is one of the major greenhouse gasses. In atmosphere,the concentration of N2O is increasing sharply. Agricultural soil is a major source of N2O emissions,accounted for approximately 70% of total global anthropogenic emissions. Nitrification,denitrification,nitrifier denitrification and dissimilatory nitrate reduction to ammonium are the main N2O generation processes. Based on clarifying of the N2O generation mechanisms,the development and research status of the process-based mechanism models[including denitrification-decomposition(DNDC),water and nitrogen management model(WNMM),DAYCENT and ecosystem model(Ecosys)]for N2O emissions from agricultural soil were reviewed and summarized. Some key issues that should be paid more attention in the future studies on the N2O emission simulation for agricultural soils,including the model mechanism improvement,parameter adjustment and enhancement of the regional simulation ability. Research on the cropland N2O generation mechanism and related models is meaningful to predict and mitigate the N2O emissions and maintain the ecological balance.