[Research advances on regulating soil nitrogen loss by the type of nitrogen fertilizer and its application strategy.]

Unreasonable application of nitrogen fertilizer to cropland decreases nitrogen use efficiency of crop. A large amount of nitrogen loss to environment through runoff, leaching, ammonia volati-lization, nitrification-denitrification, etc., causes water and atmospheric pollution, poses serious environmental problems and threatens human health. The type of nitrogen fertilizer and its application rate, time, and method have significant effects on nitrogen loss. The primary reason for nitrogen loss is attributed to the supersaturated soil nitrogen concentration. Making full use of environmental nitrogen sources, reducing the application rate of chemical nitrogen fertilizers, applying deep placement fertilizing method, and applying organic fertilizers with chemical nitrogen fertilizers, are effective practices for reducing nitrogen loss and improving nitrogen use efficiency. It is suggested that deve-loping new high efficiency nitrogen fertilizers, enhancing nitrogen management, and strengthening the monitoring and use of environmental nitrogen sources are the powerful tools to decrease nitrogen application rate and increase efficiency of cropland.氮肥的不合理施用导致氮肥利用率低下,大量氮素通过径流、淋溶、氨挥发、硝化-反硝化作用等途径损失到环境中,从而对水体、大气造成污染,带来严重的环境问题,影响人类健康.施氮量、施肥时间和方式,以及肥料种类对氮素流失量的影响显著.土壤氮素浓度过饱和是导致氮素大量流失的最根本原因,充分利用环境供氮量,减少化学氮肥施用量,采用深施等技术,以及配合施用有机肥,可以有效降低氮素的损失,提高氮素利用率.在开发应用新型高效氮肥和强化氮肥高效管理技术研究的同时,加强环境氮素的监测和利用力度,是实现减氮增效的有力手段.