Study On Transport And Transformation Test Of Nitrogen In Unsaturated Soil With Straw Cover

This study based on the natural condition and cultivation characteristic of south China. Integrate straw mulching, quantity of fertilizer and quantity of irrigation and so on to research the conversion and migration laws of nitrogenous fertilizers in the straw mulching non-saturated soil in the entire stage of winter wheat through the simulation test and theory analysis. Then seek the optimized nutrient interception and using ways. Simulate and forecast the conversion and migration laws of nitrogenous and evaluate the farm drain quality through artificial neural BP network model. The main results of study are as follows:(1)Straw mulching, quantity of fertilizer and quantity of irrigation have remarkable influence on migration, transformation and accumulation of each kind of nitrogen. Control fertilization, irrigation, straw function stimulant found that the middle nitrogen straw mulching treatment processing is superior.(2)Artificial neural BP network model is advantaged than dynamics model in this study. The migration, distribution of nitric nitrogen as well as of pollution evaluation established in the experiment has good forecast results. The forecast results of nitric nitrogen transportation model and the actual results have a good uniformity, and the magnitude of error margin of fluctuation is quite small.(3)The environment evaluation of the straw mulching test is better than other test. Drainage quality of middle nitrogen straw mulching treatment is excellent. It is indicated that straw mulching test is good to farm environment.May reduce pollution degree of the nutrient outflow to the ground water effectively and be propitious to the construction of agricultural water security of the circulatory system.