氮在紫色土中的移动和水稻氮素利用率的研究

利用养分渗漏池研究了紫色土中氮肥品种、用量对氮素移动、淋失和水稻氮肥利用率的影响。结果表明:淹水期间淋失的氮素基本形态是NH4+-N,主要分布在土壤表层,并随时间而下移;NH4+-N 淋失量与降雨量呈显著正相关;氯化铵促进了NH4+-N 的淋失,但其氮肥利用率比尿素高8 个百分点,说明水稻上可酌施含氯化肥;增施氮肥增加了NH4+-N 的淋失量,减少了氮肥利用率,建议水稻施氮控制在150kg/hm2。

STUDY ON NITROGEN MIGRATION IN PURPLE SOIL AND NITROGEN UPTAKE BY RICE

The effect of nitrogen fertilizer kind and dose on nitrogen migration, leaching loss and nitrogen utilization rate by rice in purple soil was studied in percolating pools. The results showed that during flooding period nitrogen leached basically as NH₄⁺-N which mainly distributed in soil surface layer and moved downward with time prolonging. The amount of NH₄⁺-N leaching loss was positively correlated with the amount of rainfall significantly. NH₄Cl promoted NH₄⁺-N leaching loss while its utilization rate was 8 percent points higher than of urea. So chlorine contained fertilizer can be used on rice at a judicial discretion. The increase of nitrogen dose increased the amount of NH₄⁺-N leaching loss and decreased nitrogen fertilizer utilization rate. It was also suggested that the dose of nitrogen fertilized on rice be controlled at 150kg/hm².