英语语法分析

If low nitrate concentration was applied to Jilin 20, its nodule nitrogenase activity and ureide content were increased in early growth period, but were inhibited in later growth period.

低浓度硝酸盐在生育前期对吉林20号根瘤固氮酶活性有促进作用，酰脲含量增加，在生育后期有抑制作用。