提高中国稻田氮肥利用率的研究策略

Research Strategy in Improving Fertilizer-nitrogen Use Efficiency of Irrigated Rice in China

介绍了中国水稻生产氮肥使用及利用率概况。中国氮肥消费量占世界氮肥总量的 30 %,水稻生产所消耗的氮肥占世界水稻氮肥总消耗量的 37%。与主要产稻国相比 ,中国水稻生产氮肥施用量较高而利用率较低 ;介绍了国际上公认的氮肥利用率的概念和相应的定量方法 ;总结了国内外水稻氮肥的施用方法 ,肥料种类 ,计算机推荐施肥以及实时施氮管理模式等对降低氮素损失 ,提高氮肥利用率的研究概况和研究进展 ;从水稻品种耐肥性、土壤供肥能力、施肥技术及水分管理等多方面分析了中国水稻氮肥利用率低的可能原因 ;提出了通过改善水稻品种对氮肥的敏感反应 ,以作物氮素状况为指导适时和适量施用氮肥 ,以及合理调节土壤背景氮来降低氮素损失 ,提高水稻的氮肥利用率的研究策略。

Today, about 30% of world nitrogen (N) fertilizer is consumed in China. Rice crops in China consume about 37% of the total N fertilizer used for rice production in the world. Average rate of N application for rice production in China is high and fertilizer-N use efficiency is low compared with other major rice growing countries. In this paper, we summed up research progresses made internationally and domestically on the application method, fertilizer-N sources, computer-based decision support systems, and real-time N management model in order to reduce N losses and increase fertilizer-N use efficiency. In addition to continuous increase in N rate and lack of adoption of new knowledge and technology in N management by farmers, we hypothesized that high indigenous soil N supply, adoption of hybrid and super rice cultivars, improper timing of N application, and practice of mid-season drainage could be the causes for the low fertilizer-N use efficiency in China. Future research work on improving fertilizer-N use efficiency of rice crop in China should focus more on improving cultivar's N responsiveness, proper time and rate of N application based on crop N status, and achieving optimal soil N supply capacity.