In this paper,the artificial rainfall test in the rice mature period has been made in macro-area paddy simulation.The dynamic characteristics of nitrogen and phosphorus and the losing potential of total nitrogen(TN) and total phosphorus(TP) in water under 60,48,17.4 mm/h rain intensity(expressed as y-b,y-m and y-s respectively) and different delay time as well as the effect of different rain intensity and delay time on reducing discharge have been analyzed.The results showed:(1) The TN concentration in wate...