论合理施氮的原则和指标  

The Principles and Indicators of Rational N Fertilization

作　　者：巨晓棠 张翀[1] JU Xiaotang;ZHANG Chong(College of Tropical Crops,Hainan University,Haikou 570228,China;College of Resources and Environmental Science,China Agricultural University,Beijing 100193,China)

机构地区：[1]海南大学热带作物学院,海口570228 [2]中国农业大学资源与环境学院,北京100193

出　　处：《土壤学报》2021年第1期1-13,共13页Acta Pedologica Sinica

基　　金：国家重点研发计划项目(2017YFD0200105,2016YFD0800102);国家自然科学基金项目(41830751,31861133018)资助

摘　　要：施用氮肥的主要目的是获得较高目标产量、相应品质和经济效益以及维持或提高土壤肥力。针对我国近年来过度强调施肥的环境影响,而放松施肥的生产目标和土壤培肥,导致无原则的“减氮”可能影响作物生产的趋势,本文定义了合理施氮的原则,即在特定的气候-土壤-作物体系,在一定的经营管理措施下(轮作与耕作、品种、灌溉等),能够实现可获得的目标产量、相应品质和经济效益并维持或提高土壤肥力,将环境效应降低至可接受的范围内的合理施氮量区间;论述了确定合理施氮量的方法和评判指标;论证了在当前农户常规氮素管理基础上“减氮”的实质,是要通过施肥技术的改进减少氮素损失,而不是简单地降低氮肥施用量;强调了合理施氮需要综合考虑“4R”施肥理念或技术、与有机肥和秸秆还田的结合、与磷钾肥和中微量元素的平衡施肥以及与其他农艺措施的配合与协调等。最后,建议将全国划分为不同的气候-土壤区或亚区,在这些区域的代表作物上,同时开展产量、品质、效益以及氨挥发、硝酸盐淋洗、氧化亚氮排放和土壤肥力的长期试验;研究肥料氮-土壤氮-作物吸氮之间的关系,应用氮素输入、输出、盈余、氮素利用率、损失和土壤有机碳变化等指标,综合评判生产目标、环境效应和土壤肥力状况,切忌顾此失彼;需要根据各区域的气候-土壤和生产条件,研究切实可行的施肥技术,降低氮素损失,使施用的氮肥能够被作物充分吸收利用,形成同类地区能够机械操作的规范化种植模式与合理施肥措施。The main objectives of nitrogen(N)fertilization to cropland are to obtain high target yield,accepted product quality and economic benefits,and maintain or improve soil fertility.In recent years,overemphasizing the environmental effects of N fertilization by unreasonable“reducing N”are becoming fashion while paying less attention to the production target and soil fertility,which might lead to reduce crop yield or product quality,or soil fertility.Here,we define the principles of rational N fertilization,i.e.in a given climate-soil-crop system with given relatively stable agronomic managements(such as crop rotation,tillage,cultivar and irrigation etc.),N rate should be in an rational range which could achieve high target yield,accepted product quality and economic benefits,maintain or improve soil fertility,and control N losses(thus environmental effects)in an acceptable level.We discussed the methods for determining the rational N rate and the indicators for evaluating N management.We emphasize that the essential of reducing current farmers’conventional unreasonable high N rates is to minimize N losses via improving N fertilization techniques rather than simply cutting the N application rate.We also emphasize that the rational N fertilization should implement the“4R”nutrient stewardship or techniques together with the recycling of manure and straw to cropland,and balancing other nutrients include phosphorus,potassium,middle and micronutrients,and integrating to other agronomic managements.We suggest to do long-term field experiments in different climate-soil zones to study crop yield,product quality,economic benefits,ammonia volatilization,nitrate leaching,nitrous oxide emission and soil fertility simultaneously,and to explore the relationship among fertilizer N,soil N and crop N in these climate-soil-crop systems,and further to evaluate the production target,environmental effects and soil fertility comprehensively.By using the indicators of N input,N output,N surplus,N use efficiency,N losses and change

关 键 词：合理施氮 目标产量 环境效应 土壤肥力 氮素损失 施肥技术 

分 类 号：S143[农业科学—肥料学]