农田氮肥利用率计算方法研究进展

Research advances in the calculating method of nitrogen use efficiency( NUE ) in cultivated lands

氮肥利用率是农学和环境科学等领域普遍关注的焦点,合理计算氮肥利用率是实现农田氮素优化管理的重要前提和基础.近年来,鉴于我国农田氮肥利用率测定值偏低,且存在很大变幅的事实,国内学者针对传统氮肥利用率的概念和计算方法进行了深入的思考和探讨,并提出了一些改进的尝试.本文首先综述了传统氮肥利用率在概念和计算方法上存在的种种缺陷,然后较为系统地介绍了目前学者提出的计算农田氮肥利用率的几种常见的替代方法,并对今后的研究方向进行了展望.建议在正确理解氮肥用量、作物产量、氮肥利用和损失之间辩证关系的基础上,逐步建立起符合现阶段我国农业生产现状的农田氮肥利用状况评价体系.

Nitrogen use efficiency （NUE） has received worldwide concern in the sphere of agro- nomic science and environmental science, and it is fundamentally important for evaluating N utiliza- tion status and optimizing N fertilization management in cultivated lands. In recent years, in consi- deration of low values and great variations of NUE in China＇ s cultivated lands, some scholars have discussed on the traditional concept and calculating method of NUE, and also have proposed some substituted NUE calculating methods. In this paper, we summarized some disadvantages of both conventional concept and calculating method of NUE, i.e. the subtraction method and the 15N labe- ling method. Furthermore, we particularly introduced several substituted NUE calculation methods and discussed research directions in the future. In summary, we strongly suggested the establish- ment of a comprehensive evaluation index system of N utilization in good accordance with the current agricultural production status in China, based on a correct understanding of the dialectical relation- ships among N application rate, crop yield, N utilization and N loss.