Effect of combined application of organic and mineral fertilizers on yield, quality and nitrogen uptake of rice

Controlled release nitrogen fertilizers(CRNF) are physically prepared from the granules of the field experiments were conducted to investigate the effects of different ratio of organic and mineral fertilizers(organic N accounted for 100%,70%,40%,20% and 0%,respectively) on yield,quality and nitrogen uptake of early rice,late rice and single-crop rice,under the same application rates of nitrogen.The results show that when organic nitrogen accounts for 40%,20% and 40% of the total amount,yields of early rice,late rice and single-crop rice are highest,which are increased by 8.5%,2.8% and 4.6% respectively compared with the yields of chemical fertilizer areas.When organic N accounts for 20% to 40%,rice quality is better,while higher proportion of organic N can result in rice fragile,increase chalk rate and reduce protein content.When organic N accounts for 20%,N uptake by early rice,late rice and single-crop rice was highest.