Effects of N and Zn interaction on yield and contents of N and Zn in grains of rice

The objectives of this study were to investigate the effects of combination use of nitrogen (N) and zinc (Zn) fertilizers on rice yields, and the contents of N and Zn and their accumulations in rice plants at the maturity stage under field conditions. The rice cultivar, Zhendao 11 (a normal jiponica variety, was grown under two N rates (N 200, 300 kg/ha) with six Zn levels (ZnSO47H2O 0, 10, 25, 50, 100 and 150 kg/ha). The experiment results show that the Zn fertilizer could slightly improve the rice grain yield. The nutrition quality of rice grains is enhanced with the increases of the contents of grain N, crude protein and Zn under the Zn fertilizer application and the tendency is increased with the increase of the Zn application level. In addition, compared to the normal N rate, the yield, Zn uptake and accumulation of rice plants are increased significantly under the high N rate. These results indicate that both of grain Zn concentration and protein content could be facilitated by applying Zn fertilizer and N fertilizer.