利用盆栽试验，研究尿素配施不同比例的氯化铵对菜心硝酸盐积累的影响，结果表明：随着尿素配施氯化铵比例的增加，菜心氯含量增加，硝酸盐含量下降，而全N含量、叶绿素含量和收获前的产量变化不大。

Using the pot experiments, the study of the effect of Urea-ammonium chloride mixed treatments on the nitrate content in Brassica campestris L. ssp. chinensis var. utilis Tsenet Lee was carried on, the results are as follows:With the increase of use of ammonium chloride, The Cl- content in Brassica campestris L. ssp. chinensis var. utilis Tsenet Lee increase obviously; and nitrate content reduce obviously, but the total N, total chlorophyll content and yield befor harvest don, t vary evidently.