Effects of simulated nitrogen deposition on accumulation of nitrogen assimilation of grassland plants

This research aimed to reveal impacts of atmospheric nitrogen deposition on artificial grassland plants. Bromus inermis and Trifolium repens plants were treated with 0 (CK), 6 g Nm-2a-1 (low N), 12 g Nm-2a-1 (medium N) and 24 g Nm-2a-1 (high N) to explore the effects of simulated nitrogen deposition on accumulation of partial nitrogen assimilation. The results indicated that nitrogen deposition significantly affected the accumulation of nitrogen assimilation (P0.01), and nitrogen addition at all levels affected contents of chlorophyll, leaf nitrogen, Arg and soluble protein of B.inermis and T.repens plants. All of these contents except for the proline content ascended as increasing of nitrogen concentration until the concentration reached 12 g Nm-2a-1. However, effects of nitrogen deposition on accumulation of nitrogen assimilation were different between B.inermis and T.repens, and the influence on grasses was higher than that on legumes. There was a significant positive correlation bewteen Arg content and concentration of N deposition (R2=0.99). Arg content could be used as a sensitive indicator for nitrogen deposition of herb plants.