Effects of nitrogen management practices on nutrition uptake and grain qualities of rice

Effects of nitrogen management practices on nutrition uptake and grain qualities of rice were examined using a rice cultivar, Yanglianyou 6, in a field study. The nitrogen fertilizer was applied in three splits, namely, 40% as basal, 30% at 10 days after transplanting (DAT) and 30% at 36 DAT (40-30-30), and 30% as basal, 20% at 10 DAT and 50% at 36 DAT (30-20-50), and the N application rates were set to N 0, 150 and 240 kg/ha, expressed as N0, N150 and N240, respectively. Compared to the N150 and N0 treatments, total nitrogen accumulation (TNA), total phosphorus accumulation (TPA) and total potassium accumulation (TKA) of the N240 treatment at maturity stage are increased by 21.5%, 18.5%, 18.3% and 134.6%, 127.0%, 82.7%, and rice yields are increased by 10.4% and 39.6%, respectively. Under the same nitrogen application rate, TNA and yield of the 30-20-50 split are 15.4% and 7.3% higher than those of the 40-30-30 split at the maturity stage. The grain protein of rice is improved significantly; while grain amylose content is decreased, and the quality of appearance is worsen due to the improvement of chalkyness of grain under the N240 treatment with the 30-20-50 split.