Effects of Nitrogen Amount on Yield and Nutrient Absorption of Cold Land Japonica Rice under the Condition of Straw Returning

摘要

Effects of nitrogen amount on yield and nutrient absorption of cold land japonica rice under the condition of straw returning were studied using cold land rice variety Dong Nong 428 as experimental material. The results showed as follows: yields and effective spikes increased first then reduced, and the highest yield and effective panicles per plant was 7983.33 kg·hm~(-2) and 17.7 per plant that was found in treatment with nitrogen amount was 133 kg/hm~2; differences of plant N, P and K accumulation of each treatment in tillering stage were not obvious and showed single peak curve change in heading stage while took on obvious increasing trend in grain filling stage and maturity stage. The straw returning increased effective spikes while had no effects on yield, spike weight, total shriveled rate and 1000-grain weight; the straw returning also had no effects on N, P and K accumulation in tillering and heading stage while it inhibit N, P and K accumulation in grain filling stage, and it inhibited N accumulation while promoted P and K accumulation in maturity stage.