Effects of different nutrient and water regimes on the morphology and activity of rice root system

The effects of different nutrient and water treatments on the root morphology and activity of rice plant in pot experiment were studied．The results indicate that in alternate wetting and drying model(AWD)and controlled irrigation model(DRA)，the rot active absorption areas of rice plant by the combined applications of chemical fertilizers with organic manure are 19．3％ and 28．2％ respectively larger，and the rot activities (RA)are 23．7％ and 37．9％ respectively higher，as compared with the exclusively chemical fertilizers．W hile in the water regimes of continuous waterlogging (CWL)，the effectiveness of chemical fertilizers with organic manure on improvement of the rice rot morphology and activity is greatly weakened．The combined applications of chemica1 fertilizers with organic manure increase the root surfaca acid phosphatase activity(APA)significantly，especially in the controlled irrigation，the APA of chemical fertilizers with organic manure shows 44．7％ higher than that of the chemica1 fertilizers．