小麦生长期间潮土硝态氮垂直移动规律研究

Studies on Movement Regularites of no3-Nin Wheat Growth Period in Profile of Chao Soil

１９９３～１９９４年利用渗滤法研究了小麦施用尿素、硝铵、碳铵后硝态氮在潮土土体内的分布和移动规律。结果表明，在０～６０ｃｍ范围内，不同品种氮肥及尿素不同施量处理对不同层次土壤中硝态氮含量和分布都有一定影响。且随着尿素施用量的增加，上层中硝态氮含量增加很快，垂直向下移动明显；等氮量移动规律中，３种氮肥中硝态氮向下移动的快慢顺序为硝铵＞尿素＞碳铵，施硝铵中的硝态氮主要分布在４０～６０ｃｍ土层中，碳铵中的硝态氮主要分布在０～４０ｃｍ土层中，尿素中的硝态氮分布则介于二者之间。

n l993～1994,a lvsimeter was used to study the distribution and movement ofNO_3￣-Nin Chao soil after the application of urea,ammonium nitrate and ammonium bicar-bonate in wheat growth period.The results showed that,in the 0～ 60cm soil section,theamounts and distribtions of NO_3￣- -N in various soil layers were affected hy different Nfertilizers and different urea aditions.Whih the increase of urea application,NO_3￣- - Nin-creased rapidly and moved downwards markedly.For a given N amount,the downwards-moving speeds of the 3 N fertilizers were ammonium nitrate>urea>ammonium bicarbon-ate.NO_3￣--N distributed mainly in 40～60cm for applied ammonium nitrate,in 0～40cm for applied ammonium bicarbonate and in the middle range of the above- mentioned twosections for applied urea.