Effect of Controlled Release Urea Fertilizer on Rice Yield and Nitrogen Utilization Efficiency

SUN Kegang; DU Jun; HE Ailing; ZHANG Yunhong; SUN Kezhen

Abstract：In order to discuss the enhancing effect of controlled release urea ( CRU ) on rice yield and nitrogen utilization efficiency under the condition of equal amount of nitrogen fertilizer,the effects of CRU and common urea( CU) under different dose on rice yield and nitrogen utilization efficiency were studied. The results showed that the highest yield of rice was 8 977. 5 kg/ha(Luoshan county) and 8 986. 5 kg/ha ( Gushi county) in the treatment with 100%CRU. Compared with the equal amount treatment with 100%CU,the yield of the treatment with 100%CRU significantly enhanced by 4. 40%( Luoshan county) and 4. 42%( Gushi county), respectively. There were no significant differences of rice yields between the treatments with 3/4CRU, 1/2CRU and the treatment with 100% CU, which showed that CRU with subtracting 1/4—1/2 nitrogen application amount could achieve the same yield compared with CU. The highest nitrogen utilization efficiency was 66 . 5%(Luoshan county ) and 68 . 3%(Gushi county ) in the treatment with 1/2CRU,which increased by 19. 2(Luoshan county) and 20. 6(Gushi county) percentage points compared with the equal nitrogen application amount treatment with 1/2CU, respectively. Meanwhile,CRU could reduce NO3--N accumulation in soil significantly. In summary,the treatment with 3/4CRU was optimal,according to rice yield and nitrogen utilization efficiency.