DISCUSSION
Application of organic manure, or application of chemical fertilizer combined with organic manure were propitious to the cumulation of soil organic matter and improvement of soil fertility. Yields of rice all reached a high level with different fertilization. The stability of yield, soil organic matter, nitrogen use efficiency, and soil organic matter with application of chemical fertilizer in combination with organic manure increased significantly compared with that of application of chemical
fertilizer alone. Application of chemical fertilizer combined with chemical fertilizer was propitious to alleviating environment load caused by nitrogen losses (Xu et al. 2002), this was consistent with the former results (Yu et al. 2007).