Effects Of Water, Fertilizers And Illumination On Morphological Characteristics And Uptake Of Roots In Rice

Plant root, as an important organs absorbing water and nutrients and synthesizing growth regulation, have a direct influence on plant aboveground. Roots play an important role in dryland agriculture with serious soil water restriction. Because of the difficulty in separating root techniques in soil, the studies involved plant root system have not been deepened as the studies on shooting. The adaptation of rice root resistance drought under different environments conditions would be another main part to non-full irrigation.4 rice varieties (Morokerean,IRAT109,IR62266 and IR1552)with different root systems and drought tolerance abilities were used in this experiment. The experiment was conducted in the greenhouse for studying the rice root adaptation to different environments and the relationship between root adaptation and plant nutrient conditions. The results were shown as follows:1 With soil drought was holding on, leaf water potentials of high N and K treatments were lower than normal N and K treatments significantly. Drought resistance varieties behaved strong ability to adapt to water stress condition with the lower leaf water potentials than drought sensitive varieties when leaf curved at the 5th degree. The leaf water potential of shading treatment was lower than normal sunlight when the leaf rolled the same degree. It could be alleviated the hurt of drought to rice under high K and N treatment, and shading.2 The biomass under water deficit condition were lower than adequate water supply condition. The biomass of drought sensitive varieties increased under high N treatment with water deficit, but did not the drought resistance varieties. The biomass didn't increase under high K treatment in both well-watered and water-stressed condition. The biomasses of 4 varieties did not increase significantly under high K and N treatments after re-watering, lower than under adequate water supply condition. Plant growing had been restrained under low N treatment especially after re-watering.3 Root had some behavior to change characteristics so that it could be accommodated by different fertilizer and water conditions. The root biomass increased with high N and K applications under well-watered condition, but did not increase under water deficit condition. The 4 varieties' root biomasses did not increase under high K treatment after re-watering. But 4 varieties had different responses to high N after re-watering, root biomasses of drought sensitive varieties increased, drought resistance varieties did not. Shading prevented shooting and root growing through the experiment. Root biomass did not increased significantly by high K...