Nitrogen uptake and utilization under different nitrogen management and influence on grain yield and quality in rice

Field experiments were conducted to study N uptake and utilization under different N rates and panicle fertilizerdistribution ratios (PFDR) and influence on grain yield and quality in three rice varieties. Results showed that high N rate increasedtotal N accumulation and reduced N production efficiency and N harvest index. Under the same N rate, greater PFDR increasedtotal N accumulation, N recovery efficiency, N transportation efficiency and decreased N production efficiency. Changes of Nuptake and utilization under different N management have an important influence on grain yield and quality. Increase of Naccumulation increased protein content in grains and effective panicles, but reduced seed setting rate. N dry matter productionefficiency increased with increase of seed setting rate, protein contents in grains and effective panicles reduced. N harvest indexincreased and chalky rice ratio and area enhanced, and effective panicles reduced.