Experimental Study On Effects Of Farmland Water Level Management On Paddy Growth And Development Indexes

Based on the experiential data, the dynamic change rules of the main growth and development indexes which included leaf age, leaf area index, stem tiller number, plant height and root system were analyzed under the different water level management. The relationships were established between the different water level management and the main growth and development indexes, the water level management and the output. Paddy high-production mechanism was explored under the farmland water level management. The multinomial models were used to simulate the leaf area index. Two kinds of models were used to simulate the stem tiller number separately, which included one unknown number multinomial model and the Logistic revision model.The results were showed that the change tendencies of level age. leaf area index, stem tiller number and plant height performed similar which all displayed the singlet curve under the different water level management. The growth and development indexes assumed escalating tendency during the vegetative growth stage. The growth and development indexes assumed drop tendency during the reproductive stage.The influences of different water level management to each growth and development indexes were different in each growth and development stages. The level age grew quickly under the light flood disposal and the normal water level, on the contrary grew slowly under the heavy flood disposal and the light drought disposal. The leaf area index value grew quickly during the vegetative growth stage and also reduced quickly during the reproductive stage. The different water level disposals played the varying differences in the leaf area index changes. The suitable water level slightly affected the leaf area index changes, but the unsuitable water level heavily affected the leaf area index changes. The stem tiller number both suffered from the drought and flood disposals. The drought and flood disposals both restrained the growth of paddy stem tiller number. Among the different water level management, the plant was highest under normal water level. The plant was higher under the flood disposal. The drought disposal restrained the paddy height growth. After suffering from the heavier drought disposal, the root system was more developed. The root system was mainly composed by white root under the drought disposal and composed by black root under the flood disposal. When the water level was moderate, the paddy theoretical yield was high. The theoretical yield was low under the drought and flood disposal. The results of all simulations to the leaf area index and stem tiller number all simulated the dynamic change rules. The all simulations achieved the remarkable level when the alfa amounted 0.05. The Logistic revision model suited the dynamic simulation of the stem tiller number.