Effect of Nitrogen Application Rate on Yield,Quality and Nitrogen Utilization Efficiency of Super Early Rice

Zhuliangyou 819 and Luliangyou 996 were used as materials to study the effects of N application rate on yield formation,rice quality and N utilization efficiency of supper early rice.The results indicated that:(1) Yield of super early rice was increased significantly by N application,which was induced by increase of grain number per panicle for Zhuliangyou 819 and increase of grain number per panicle and 1000-grain weight for Luliangyou 996.(2) Yield in treatment of N225 kg/hm2 was significantly lower than that in treatment of N150 kg/hm2,and two combinations showed the same trend.(3) With the increment of N application rate,the content of protein in rice was increased,while amylase content was decreased,and the same trend was observed for two varieties.(4) Positive correlation existed between yield and leaf area and dry matter accumulation,and negative correlation existed between yield and ratio of grain to leaf area.(5) With the increment of N application rate,N accumulation of two combinations was significantly increased,while N use efficiency,N fertilizer efficiency,N uptake efficiency,N physiological efficiency and N utilization efficiency were significantly decreased.In this study,N150 kg/hm2 for super early rice could gain higher yield,at the same time,higher N use efficiency,N uptake efficiency and N utilization efficiency could be gained.