Effects of Controlled Release Urea on Physiological Characteristics and Nitrogen Use Efficiency of Rice and NO3--N Contents in Soil

• Main Authors: DU Jun, SUN Ke-gang, ZHANG Yun-hong, HE Ai-ling, SUN Ke-zhen
• Format: Article
• Language: zho
• Published: Agro-Environmental Protection Institute, Ministry of Agriculture 2016-03-01
• Series: Journal of Agricultural Resources and Environment
• Subjects: controlled release urea; rice physiological characteristics; nitrogen use efficiency; soil NO3 > N
• Online Access: http://www.aed.org.cn/nyzyyhjxb/html/2016/2/20160205.htm

Field experiments were conducted to study the effects of controlled release urea(CRU) on key enzymes activities of nitrogen metabolism of rice, nitrogen use efficiency and soil and NO3--N contents, in order to verify the mechanism of CRU on increasing nitrogen use efficiency and increasing soil NO3--N accumulation. The results showed that CRU could improve significantly nitrate reductase(NR) activities of rice leaves in full heading stage and milk stage, especially in milk stage. The activities of glutamine synthetase and glutamine transversase of rice leaves were obviously increased, and the enhancement continued till dough grain stage, especially in full heading stage. Meanwhile, CRU was able to promote significantly protease activity of rice leaves in milk stage and dough grain stage. The treatment of 4(CRU60%+PU40%) was the best treatment of the key enzymes activities of nitrogen metabolism. CRU also had better effect on promoting glutamine synthetase and glutamine transversase activities of brown rice, and increased significantly rice yield and nitrogen use efficiency, especially the treatment of 4. CRU enhanced significantly protein contents in brown rice, therefore which improved quality of rice to some extent. Moreover, CRU could reduce NO3--N accumulation in soil profile significantly. CRU application could evidently decrease the quantity of soil NO3--N leached to deep soil and lessen the risk to ground water pollution.