施用涂层尿素对水田土壤氮去向及其利用率的影响

Effect of Coated-Urea Application on the Fate and Utilization Efficiency of Nitrogen in Paddy Soil

采用水稻盆栽试验方法，研究施用涂层尿素对水田土壤氮的挥发、土壤残留、水稻吸收三个去向及其氮素利用率的影响。研究结果表明：施用涂层尿素可显著抑制NH3和NOx挥发损失，NH3和NOx挥发量之和的减少幅度为22．1％～24．8％；使土壤中全氮含量增加，增加幅度为1．9％～2．1％。等氮用量条件下，施用涂层尿素可极显著提高氮素利用率，其提高幅度随施用量增大而减小；使水稻经济产量显著增加，中用量和高用量水平处理经济产量增加幅度分别为21．8％和21．5％。说明施用涂层尿素不仅能提高水田土壤氮素利用率，而且可减轻生态环境污染。

Pot experiments of planting rice were conducted to investigate the fate and utilization efficiency of nitrogen after coated urea application in paddy soil. The fate of nitrogen includes nitrogen volatilization, soil residual and rice uptake. The results showed that coated urea application inhibited the volatilization loss of nitrogen（ NH3 ＋ NOx ） by 22. 1 -24.8% and total soil nitrogen increased by 1.9% -2.1%. Compared with the same amount of nitrogen addition, coated urea application could markedly increase the utilization efficiency of nitrogen, while the utilization efficiency was reduced with the increase of coated urea amount. The economic yield of rice was also increased and the increment at the medium and high level of nitrogen was 21.8% and 21.5%, respectively. The finding indicated that coated urea addition to paddy field not only improved the nitrogen utilization fficiency, but also reduced nitrogenous volatilization loss and the ecological environment pollution.