近10年中国大陆主要粮食作物氮肥利用率分析

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、274 kg hm-2。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、11.1 kg kg-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=0.848 9,小麦R2=0.657 5,玉米R2=0.791 7,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180~240 kg hm-2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。

Nitrogen use efficienciesof major grain crops in China in recent 10 years

Using the method of literature research, the data about nitrogen fertilizer effects published on the CNKI and VIP database since 2004 were analyzed. The results showed that currently, under the condition of no nitrogen fertilizer application the yields of the three major grain crops achieved 68% ~ 76% of the maximum yields that got under the condition of nitrogen fertilizer application. According to the dependent equation of nitrogen application rates and relative yields, when the nitrogen application rates of rice, wheat and maize were 246.25, 250.13, 274.25 kg.hm-2 respectively, their yields reached the maximum. In recent 10 years, the apparent recovery efficiency of applied nitrogen(REN) and agronomic efficiency of applied nitrogen(AEN) in the rice, wheat and maize were all increased, with REN 39.00%, 34.80% and 39.00%, AEN 12.66, 9.20, 11.14 kg.kg-1 respectively. Compared with the average value of 27.5% resulted from the investigation from 2001 to 2005, REN was increased by 0.6% currently, alomost reaching 35% that was the level in 1980s. There were power exponent relationships between nitrogen application rates and partial factor productivities from applied nitrogen(PFPN), and the R2 in the rice, wheat and maize were 0.8489, 0.6575 and 0.7917 respectively. The PFPN was the appropriate indicator to evaluate the nitrogen fertilizer effect at present. Considering the yields, nitrogen application rates under the maximum yields and nitrogen use efficiencies, it recommended that 180 - 240 kg.hm-2 is the proper application rate of nitrogen fertilizer in the three main grain crops in China.