Optimization of nitrogen fertilization improves rice quality by affecting the structure and physicochemical properties of starch at high yield levels oleh Tian-yang ZHOU, Zhi-kang LI, En-peng LI, Wei-lu WANG, Li-min YUAN, Hao ZHANG, Li-jun LIU, Zhi-qin WANG, Jun-fei GU, Jian-chang YANG