中文摘要：

用什么指标（indicators或indexes）来衡量不同尺度或生产体系氮素管理的优劣,是提高氮素管理水平的核心问题。近年来,国际上在氮素管理方面提出了许多新概念、方法和指标,以客观评价和改进氮素管理水平,为生产者和政策制定者提供评判标准。本文系统介绍了国际上氮素管理指标的概念、含义、计算方法及对结果的解析,包括：（1）氮素投入、收益与环境效应的关系;（2）氮素收支（budget）、氮素平衡（balance）和氮素盈余（surplus）;（3）氮素利用率（Nitrogen Use Efficiency,NUE）;（4）氮素利用率与氮素输入、输出及盈余的关系;（5）旱地作物收获后土体硝态氮允许残留量（Residual nitrate-N）。在此基础上,汇总了我国在不同尺度、不同土壤-作物体系氮素研究结果,初步建立了我国典型农田的氮素管理指标,为实现优良的氮素管理提供科学依据。

英文摘要：

To assess the nitrogen（N）management in different production systems or under different scales,choosing which indicators or indexes is crucial question to be answered for improving the N management.Recently,many new concepts,methods and indicators have been proposed for the N management internationally,to objectively evaluate and improve the N management level,and to provide criteria for producers and policy makers.Although these concepts and methods have been applied to the N studies and management in China in some cases,the understanding of these concepts and methods,and how to make the calculation and interpret the results still lacks systemic knowledge.No indicators thus have been developed to guide the policy making and practical application for the N management in agricultural systems in China.Therefore,this paper introduces the concepts,definitions,calculations and result analysis of international N management.On the basis of this introduction,we attempt to integrate the results from N studies under different scales and in different soil-crop systems,summed up the N management indicators for typical crop systems,and provide a scientific basis for achieving the better N management.This study conducted literature searches on the N management indicators,summarized the concept and calculation methods of main N management indicators,including N budget,N balance,N surplus,and N use efficiency（NUE）,and allowable residual nitrate in upland crops soil after harvest,and analyzed the relationship between these metrics.Results show：（1）The environmental cost is low if the N input-output of a production system within a reasonable limit under a certain technical and management level;the environmental cost increases rapidly with the increase of input after the net benefit reaching the maximum level;N inputs should be maintained within this limit.（2）N balance is an important indicator of N management and policy making,which is defined as the relationship between detail N inputs and outputs of a given syste