Assessment of Nitrogen and Phosphorus Non-point Source Pollution from Rice Field

Under the condition of natural rain and through the method of field runoff plots, a field experiment with 6 kinds of water and fertilizer managements in 5 years was carried out to study the effects of water and fertilizer managements on the concentration and loss of nitrogen and phosphorus by runoff from paddy field. Results showed that: Water quality of runoff under “none fertilization and routine irrigation”(CK) was the best, and which under “optimization fertilization and optimization irrigation”(OF+OI) took the second place. And the loss of nitrogen and phosphorus under CK was the least, and which under OF+OI was less. Thus, we can conclude that it is an economical and effective measure to control nitrogen and phosphorus non-point source pollution from paddy field by using the treatment of OF+OI.