关键词: 水稻, 水稻, 杂草, 群落

Abstract: To improve the nitrogen application methods to early rice in southern Hunan, clarify the key application techniques and construct a high-yield and high-efficiency application mode, a two-factor splitplot experiment with the application rate as main factor and the fertilizer planning mode as secondary factor was conducted and its impact on yield formation and nitrogen utilization efficiency was studied. The results showed that: (1) tiller number and leaf SAPD value at maturity stage of early rice increased with the increase of nitrogen fertilizer rate and ratio of ear and grain nitrogen, the yield had no obvious change when nitrogen rate was from 150 kg/hm2 to 210 kg/hm2, while was significantly increased by increasing the ratio of ear and grain nitrogen with 180 kg/hm2 nitrogen rate; (2) increasing the nitrogen rate could significantly improve the whole head rice rate and rude protein content, and reduce the chalky rice rate, increasing the ear and grain nitrogen ratio could increase the whole head rice rate, amylose content and crude protein content, but reduce the alkalispreading value; (3) with the increase of nitrogen rate, the nitrogen accumulation of early rice significantly increased, but the NPFP, ANUE and NRE significantly decreased, with the increase of the ratio of ear and grain nitrogen, the nitrogen accumulation significantly increased, and the NRE NPFP and ANUE in medium nitrogen level treatment significantly increased. On the whole, when the nitrogen rate is 180 kg/hm2, the increase of the ratio of ear and grain nitrogen is beneficial to improving yield, rice quality and nitrogen utilization efficiency of early rice.