Effects of nitrogen on nodule-forming and nitrogen concentration in soybean leaves

Three soybean varieties were examined to study the effects of different nitrogen application levels on nodule-forming and nitrogen concentration. Results showed that, high nitrogen application in basal fertilizer inhibited nodule-forming, and the duration of inhibiting effect varied with varieties. There existed a similar nitrogen concentration tendency among the varieties, but the peek point of the variety with longer growth period appeared later. Nitrogen application could increase the nitrogen concentration in leaves, but prolonged the maximum stage. It could also stimulate the growth of soybean, optimize the components of yield and increase the production of soybean.