利用３ 个不同土样在实验室内进行不同浓度双氰胺（ＤＣＤ） 对土壤ＮＨ４Ｎ 含量变化影响的模拟试验，得出在不同土壤上施用普通碳酸氢铵（ 以下简称普通碳铵） 添加ＤＣＤ 的最佳浓度。结果表明：添加ＤＣＤ 各处理的土壤ＮＨ４Ｎ 含量均高于只施普通碳铵的处理；在紫色土、潮土和黄壤上添加ＤＣＤ抑制ＮＨ４Ｎ 损失和转化的效果分别以０－５ ％ 、０－３ ％ 、０－３ ％ 浓度为最佳。 Using three different soil samples in the laboratory for different concentrations of dicyandiamide (DCD) on soil NH4  N content changes in simulated experiments, obtained in different soil application of ordinary ammonium bicarbonate (hereinafter referred to as ordinary ammonium bicarbonate) added The optimal concentration of DCD. The results showed that the contents of NH4N in soils supplemented with DCD were higher than those in normal ammonium bicarbonate treatments. The effects of adding DCD on purple soil, alluvial soil and yellow soil to inhibit NH4N loss and transformation were 0-5% , 0-3%, 0-3% concentration is the best.