Effect of different nitrogen management patterns on grain yield and radiation use efficiency of middle-season indica super hybrid rice.

The middle-season indica super-hybrid recombination Liangyou293 was used to study the performance of grain yield and radiation use efficiency(RUE) under three treatments of nitrogen management patterns.Site-specific nutrient management applied nitrogen 120 kg/hm2;Real-time nutrient management applied nitrogen 120 and 210 kg/hm2,and farm fertilizer practice applied nitrogen 210 kg/hm2.The result showed that,with the same amount of nitrogen fertilizer,the performance of grain yield increased and RUE improved.The site-specific nutrient management pattern was better than any other other patterns.The total number of effective panicles,leaf area index in the middle and late growth stage,and the accumulation of total dry matter significantly increased and the disease index of sheath blight also decreased,which suggested that these might be the main causes for the increase of grain yield and RUE under site-specific nutrient management pattern.Compared with real-time nutrient management,the grain yield,total number of effective panicles,dry matter and radiation use efficiency of site-specific nutrient management increased by 1.61%,10.3%,13.3% and 12.0% respectively,and that of ShBI decreased by 17.2% with the same applied nitrogen 120 kg/hm2.