农业系统溶解性有机态氮淋滤损失及影响因素研究进展

Review on Dissolved Organic Nitrogen Loss and Its Influencing Factors in Agricultural Systems

农田土壤氮素的淋溶影响农田土壤和水环境质量的演变,是农业非点源污染的重要过程。农业系统中传统观念认为氮渗漏由硝酸盐控制。过去人们认为土壤淋失过程中,进入水中的主要是无机态氮,计算氮均衡时经常忽视有机态氮。但是近年来人们发现土壤有机态氮淋失现象可能比无机态氮淋失更为严重,有机态氮渗漏进入河流和饮用水源地导致富营养化和酸化,对人类健康带来很大的风险。从有机态氮的分类和定义、收集溶解性有机态氮(DON)的方法及其提取方法、对农业系统有机态氮淋滤损失及其控制因素研究进行了评述,阐明了农业系统中影响有机态氮淋滤损失的因素,以及它将给人类健康和环境带来风险的程度。如何定量研究农业系统DON淋滤损失是未来研究的方向。

Farmland soil nitrogen leaching influences the evolution of the farmland soil and water environment quality, and it is an important process of the agricultural non-point source pollution. Conventional wisdom postulates that leaching losses of N from agriculture systems are dominated by NO3. It was once thought that soil leaching process included mainly inorganic nitrogen into the water, with ignoring the organic nitrogen in computing the amount of nitrogen balance. But in recent years, it was found that the soil organic nitrogen leaching phenomenon may be more serious than inorganic nitrogen leaching, organic nitrogen leakage into the river and the water source of reference caused eutrophication and acidification. The classification of organic nitrogen and soluble organic nitrogen, extraction methods of organic nitrogen, organic nitrogen leaching losses of agricultural system and its controlling factors are discussed, and factors influencing the organic nitrogen leaching losses in agricultural system and risks to human health and environment are reviewed. How to quantitatively study the organic nitrogen leaching losses in agricultural system is the direction of future research.