A primary study on effect of nitrogen fertilization on physiological characteristics of Bromus inermis

The three yearaged Bromus inermis grassland was used to study the physiological characteristics of B. inermis under 4 different nitrogen fertilization treatments. The results showed that the chlorophyll content in leaf increased continuously with the increase of nitrogen application amount. The content of soluble sugar under different fertilization treatments was significantly higher than that of control, however, the content of free amino acid showed an opposite trend. The activity of nitrate reductase in moderate and high level fertilization treatments was significantly higher than that of control. The content of nitrate nitrogen was significantly increased only in high level fertilization treatment.