西洋参全年硝酸还原酶活性(NRA)曲线呈2个高峰, 4月中下旬和7月上旬分别出现最高峰和次高峰, 两峰出现前是施氮的重要时期。不同光照和不同pH的实验显示, 200001x和酸性的根部环境具有较高的硝酸还原酶(NR)值.

Two peaks were Present in the NRA annual curve of Panax quinque/ofius, A high peak appeared in late April and a smaller peak occured in early July, It is important to apply NR fertilizers just before the appearance of the two peaks.Experiment on the effect of di· fferent light and pH showed that higher NRA were formed at 4000 Lx and pH 4.3~6.0.