控释尿素对水稻产量、氮肥利用率及土壤硝态氮含量的影响

为探讨等量氮肥及合理节肥条件下，控释尿素对水稻的增产效应及氮素的高效利用，通过田间试验，比较分析了控释尿素(CRU)和普通尿素(CU)在不同施用量下对水稻产量、氮肥利用率及土壤硝态氮含量的影响。结果表明：CRU100%处理的产量最高，达8986.5 kg/hm²，较同等氮素用量的CU100%处理增产380.7 kg/hm²，差异呈显著水平。CRU3/4处理与CU100%处理，以及CRU1/2处理与CU100%处理之间产量差异不显著。这说明与普通尿素相比，控释尿素减少1/4~1/2的氮素用量时也能达到同样的产量水平。氮肥利用率以CRU1/2处理最高，达68.3%，较同等氮素用量的CU1/2处理提高20.6个百分点。同时，控释尿素还可明显降低水稻土壤中硝态氮的含量，减少硝态氮向土壤深层渗漏数量，以减轻对地下水污染风险。

Effects of Controlled Release Urea on Rice Yield, Nitrogen Use Efficiency and Soil Nitrate Nitrogen Content

In order to investigate the effect of controlled release urea on rice yield and high efficient utilization of nitrogen under the conditions of equal amount of nitrogen fertilizer and reasonable fertilizer, field experiments were conducted to analyze the effects of controlled release urea (CRU) and common urea (CU) with different application doses on rice yield, nitrogen use efficiency and soil nitrate nitrogen content. The results showed that the highest yield of rice was 8986.5 kg/hm² in the treatment of CRU100%. Compared with CU100%, the rice yield in the treatment of CRU 100% increased by 380.7 kg/hm², the difference was significant. There was no significant difference in the rice yields between the treatments of CRU3/4 and CU100%, and CRU1/2 and CU100%, suggesting that 1/2 to 3/4 nitrogen application rate with CRU could get the same yield as CU treatments. The highest nitrogen use efficiency was 68.3% in the treatment of CRU1/2. Compared with CU1/2 treatment of the equal nitrogen application, the nitrogen use efficiency of CRU1/2 was increased by 20.6 percentage point. Meanwhile, CRU could slow down nitrate nitrogen accumulation in soil profile significantly. The application of CRU could evidently reduce the quantity of soil nitrate nitrogen leaching to deep soil layer and therefore lessen the risk of ground water pollution.