中国主要粮食作物肥料利用率现状与提高途径

NUTRIENT USE EFFICIENCIES OF MAJOR CEREAL CROPS IN CHINA AND MEASURES FOR IMPROVEMENT

总结了近年来在全国粮食主产区进行的1 333个田间试验结果,分析了目前条件下中国主要粮食作物水稻、小麦和玉米氮磷钾肥的偏生产力、农学效率、肥料利用率和生理利用率等,发现水稻、小麦和玉米的氮肥农学效率分别为10.4 kg kg-1、8.0 kg kg-1和9.8 kg kg-1,氮肥利用率分别为28.3%、28.2%和26.1%,远低于国际水平,与20世纪80年代相比呈下降趋势。造成肥料利用率低的主要原因包括高产农田过量施肥,忽视土壤和环境养分的利用,作物产量潜力未得到充分发挥以及养分损失未能得到有效阻控等。要大幅度提高肥料利用率就必须从植物营养学、土壤学、农学等多学科联合攻关入手,充分利用来自土壤和环境的养分资源,实现根层养分供应与高产作物需求在数量上匹配、时间上同步、空间上一致,同时提高作物产量和养分利用效率,协调作物高产与环境保护。

Nutrient use efficiency is an important index not only for fertilizer recommendation on the field scale but also for forecasting fertilizer demand on the regional and national scales, however, exact nutrient use efficiencies of the major cereal crops in China are not well known yet. In this paper,data from 1333 field experiments were collected and used for analysis and evaluation of partial factor productivity （PFP） , agronomic efficiency （AE） , apparent recovery efficiency （RE） and physiological efficiency （PE） of these crops. Results show that AEN of rice, wheat and maize was 10.4kg·kg^-1,7.99kg·kg^-1 and 9.80kg·kg^-1 ,respectively,and REN of rice,wheat and maize was 28.3% ,28.2% and 26.1% ,respectively,obviously much lower than the world＇s average,which is attributed to over-use of chemical fertilizer, ignorance of contribution of nutrients from the environment and the soil, failure to bring crop yield potential into full play, and inability to inhibit nutrient losses effectively. Based on such analyses, some measures to drastically improve nutrient use efficiencies are suggested in this paper, such as adopting a muhidisciplinary approach involving plant nutrition, soil science,and agronomy, making full use of nutrients from the soil and the environment, matching rhizospheric nutrient supply with nutrient demand of high yielding crops, spatially and temporally in coincidence. Thus higher crop yield and higher nutrient use efficiency can be realized simultaneously, while high crop yield and environmental protection can be maintained in harmony.