近10年中国大陆主要粮食作物氮肥利用率分析

NITROGEN USE EFFICIENCIES OF MAJOR GRAIN CROPS IN CHINA IN RECENT 10 YEARS

利用文献调研的方法，对中国知网和维普数据库公开发表的研究时间为2004年以来的中文氮肥效应研究相关文献及数据进行了统计分析。结果表明：目前三大粮食作物可获得的不施氮肥的基础产量可达到施氮条件下最高产量的67．9％～75．9％；根据施氮量与相对产量的回归方程，水稻、小麦、玉米的最高产量施氮量分别为246、250、274kghm-1。近10年我国氮肥表观利用率、农学效率有所提高，水稻、小麦、玉米氮肥表观利用率分别为39．0％、34．8％、29．1％，农学效率分别为12．7、9．2、11．1kgkg-1；氮肥表观利用率较2001—2005年统计结果提高6．8百分点，基本达到20世纪80年代的平均水平（35％）。三大粮食作物的氮肥施用量与氮肥偏生产力的相关性均可以用幂指数方程拟合，且拟合效果均较好，水稻R2=0．8489，小麦R2=0．6575，玉米R2=0．7917，偏生产力是现阶段评价氮肥料效应的适宜指标。综合考虑三大粮食作物的产量要求和氮肥利用率，本研究认为180～240kghm“的施氮量是目前我国三大粮食作物较适宜的施氮量范围。这与国家农业部办公厅发布的《小麦、玉米、水稻三大粮食作物区域大配方与施肥建议》的推荐施氮量有较高的一致性。

Application of nitrogen fertilizer is an important approach to ensurance of food security in China. In recent years a large volume of nitrogen fertilizer applied has, though, increased crop yields significantly, it has also at the same time brought about a series of serious environmental problems. So, it is of great importance to get to know well the current situation of nitrogen use efficiency in China, to how to coordinate agricultural benefit with environmental impacts of the use of nitrogen fertilizer in formulating a reasonable fertilization strategy. Therefore, on the basis of the researches accomplished in the 1980s and 2001--2005, nitrogen use efficiencies in the resent 10 years of major grain crops in China were analyzed in this research. The literature research method was used to retrieve all the papers （ in Chinese ） related to the subject of crop response to nitrogen fertilizer application from the CNKI and VIP databases published after 2004. Results show that currently the basic yields of the three major grain crops without nitrogen fertilization could reach up to 67.9% - 75.9% of the maximum yields of the crops with nitrogen fertilization. Yield response of rice, wheat and maize to nitrogen fertilizer application might reach up to 43.0%, 28.2% and 25.8%, respectively. Based on the regression equation of nitrogen application rates and relative yields, the nitrogen application rate for maximum yield of rice, wheat and maize was 246, 250 and 274 kg hm-2, respectively. In the recent 10 years, both the apparent recovery rate （ REN ） and agronomic efficiency of applied nitrogen （AEN） somewhat increased, reaching up to 39.0%, 34.8% and 29.1%, and 12.7, 9.2 and 11.1 kg kg-1, respectively, for rice, wheat and maize. Compared with the statistics of the period （2001--2005） , REN increased by 6.8%, almost reaching 35% of the level in the 1980s. The relationship between nitrogen application rate and partial factor productivity （ PFPN ） of nitrogen fertilizer could be well described with the power exponent equation for all the three major crops, with R2 for rice, wheat and maize being 0.848 9, 0.657 5 and 0.791 7, respectively. Currently, PFPN is an appropriate index for use in evaluating nitrogen fertilizer utilization efficiency. Taking into overall account target yields and nitrogen use effieieneies of the three major grain crops, it is held that 180 - 240 kg hm-1 is the proper N application rate for all the three crops in China today, and quite in consistence with the recommendation in the ＂Fertilizer Formulas and Fertilization Recommendations for Wheat, Maize and Rice in their Major Production Regions＂ promulgated and distributed by the Ministry of Agriculture of China.