Research On Reduce Nitrogenous And Control Phosphate And Clean Production Technology Test In Hetao Irrigated District Of Inner Mongolia

Chemical fertilizers and pesticides usage is the trend of the enlarged year by year in agricultural production process of Hetao irrigation district in Inner Mongolia, but the fertilizer use efficiency has been not improved, surface source pollution in general will be the serious restriction factor of water environment quality improvement in Yellow River upstream irrigation district. At present, the pollution characteristic of back water of the agricultural irrigation area to be unclear, technology of back water pollution control is not mature. Therefore, circle about the agricultural back water pollution control of irrigation district and safeguard the Yellow River water quality security needs, developing the key technology research of agriculture back water pollution control, is the important guarantee for the technology needs of the Yellow River water quality security and improve the level of irrigation area agricultural clean production. It has important scientific research value and practical significance.The research bases on the basic farmland production status of Hetao irrigation district, take reduces the characteristic pollutant load in the farmland production as the point, in view of wheat interplanting sunflower of Hetao irrigation district in Inner Mongolia, exploring the key technology of farmland nitrogen and phosphorus reasonable decrement, revealing the relationship between soil nutrient content and nutrient loss under the different applying fertilizer intensity, studying the time and space distribution of leaching loss of different applying fertilizer intensity N and P nutrient source in soil and groundwater and relevance of fertilization strength and nutrient losses, proposing the clean production applies fertilizer the standard system, to provide the theory and the practice basis for making effective prevention and control measure of surface source pollutant. The main results of paper are as follows: The experimental research of different applying fertilizer level to the fertilizer effect of intercropping crop and use efficiency shows that, N₂P₂K₂ treatment can significantly improve crop yields and fertilizer use efficiency. It meets the demand for nitrogenous fertilizer of wheat interplanting sunflower and reduces the fertilizer loss in soil body effectively.The research of TN and TP migration rule in field leaching water indicates that, TN and TP is highest after first time irrigation and smallest after autumn irrigation. N₃ and the custom applying fertilizer level easy to create the nitrogen outflow in the soil. After each time irrigation, the sunflower area produces the nitrogen outflow is bigger than the wheat area, variation coefficient of TP or less the same.The research of TN and TP migration rule in undisturbed soil indicates that, N₃P₂K₂ treatment causes greater nitrogen loss to the wheat area and sunflower area. Applying too much and too little phosphate fertilizer is not good for crops to the absorption of nitrogen, easy to create the soil nitrogen outflow. The local custom applies fertilizer and N₂P₃K₂ treatment easily to create the outflow of phosphate fertilizer. N1P₂K₂ treatment could easily lead to the outflow of phosphate fertilizer in wheat area after 75 days of wheat sowing (10 days after sowing of sunflower).The research of influence of the soil residual nitric nitrogen under the wheat intercropping sunflower condition shows that, after wheat harvest, 40⁶0cm soil layer of N₂P₂K₂ and N₃P₂K₂ and N₂P₀K₂ and N₂P₁K₂ and N₂P₃K₂ and custom applying fertilizer treatment causes the obvious nitric nitrogen accumulation phenomenon in wheat area. Custom applying fertilizer and N₃P₂K₂ treatment could easily lead to the outflow of nitric nitrogen in soil, N₂P₂K₂ treatment can effectively improve the absorption efficiency of crops on nitric nitrogen. After sunflower harvest, nitric nitrogen content in sunflower area 120¹60cm soil layer of local customs and N₃P₂K₂ and N₂P₀K₂ levels is significantly higher than the rest applying fertilizer level, easily lead to the loss of nitric nitrogen into the groundwater.Fertilizer effect model and simulation results show that, the advices of clean apply fertilizer suits for wheat intercropping sunflower in Hetao irrigation district are as follows, the optimum fertilization of wheat is N 69.79 kg/hm² and P 38.28 kg/hm² and K 32.17 kg/hm², the best applying fertilizer ratio of wheat area is N:P:K=2.2:1.2:1; optimum fertilization of sunflower is N 76.77 kg/hm² and P 43.41 kg/hm² and K 31.61 kg/hm², the best applying fertilizer ratio of sunflower area is N:P:K=2.4:1.4:1.