Dry matter accumulation and nitrogen migration of high-yielding spring maize for different nitrogen efficiency in the flowering and milking stages

Dry matter accumulation and nitrogen use efficiency in four genotypes of high\|yielding spring maize under traditional nitrogen(FTN) and high-yielding nitrogen(HYN) treatments were studied in this experiment. The experimental varieties are Xianyu 335(XY335), Zhengdan 958(ZD958), Neidan 314(ND314) and Sidan19(SD19) and the dry matter and nitrogen use were examined in the flowering and milking stages. The results showed that yield of XY335 and ZD958 were significantly higher than those of ND314 and SD19 under two nitrogen levels. In traditional nitrogen treatment, the yield of ZD958, XY335, ND314 and SD19 were 13512, 13381, 12260 and 11932 kg/ha, with the order of ZD958, XY335 ND314, SD19. In high-yielding nitrogen treatment, the yield of XY335, ZD958, ND314, SD19 were 16364, 15895, 13916 and 12717 kg/ha, with the order of XY335, ZD958 ND314 SD19. In traditional nitrogen treatment, the yield differences between low nitrogen efficiency and high nitrogen efficiency genotypes mainly due to different dry matter transfer in vegetative organs before silking stage, while the difference of grain nitrogen accumulation mainly comes from the nitrogen synthesis amounts after silking stage. In high yield nitrogen treatment, yield of different nitrogen efficient varieties come from the dry matter transfer in vegetative organs before flowering and dry matter synthesis amount after silking stage. Grain nitrogen accumulation of different nitrogen efficient varieties come from the nitrogen transfer in vegetative organs and the nitrogen synthesis after silking stage. Nitrogen efficient varieties in traditional nitrogen and high-yield nitrogen levels can improve yield and nitrogen content of grain. Nitrogen use efficiency was enhanced in high-yield nitrogen levels, and dry matter and nitrogen uptake and transfer increased during the flowering and milking stages.