Abstract:A field experiment was conducted in the Sucheng District, in Suqian of Jiangsu Province, in order to study the changes of the concentrations of nitrogen and phosphorus in surface drainage from a paddy field after a rainstorm with different irrigation and drainage modes, and to reduce agricultural non-point source pollution and improve the utilization efficiency of nitrogen fertilizer. The experimental results show that, compared with conventional irrigation and drainage modes, the controlled irrigation and drainage mode caused an 18. 7% reduction in total irrigation water, a 50. 6% reduction in total drainage water, and a 3. 6% reduction in rice yield. As the controlled irrigation and drainage mode increased the storage water depth in the paddy field, it caused drainage to decrease after the rainstorm, the drainage time to be delayed, and the total amounts of NH+4-N, NO-3-N, TN, and TP losses in the surface drainage from the paddy field to decrease by 48. 15%, 49. 09%, 45. 54%, and 49. 10%, respectively, indicating a significant effect in water conservation and drainage reduction.