【作者】 刘德平；

【导师】 杨树青；

【作者基本信息】 内蒙古农业大学 ， 农业水土工程， 2011， 硕士

【摘要】 内蒙古河套灌区农业生产过程中化肥、农药用量呈逐年加大的趋势,而肥料的利用率一直得不到提高,面源污染总体将成为黄河上游灌区水环境质量改善的严重制约因素。因此,围绕黄灌区农业退水污染控制和保障黄河水质安全的需求,开展农业退水污染控制关键技术研究,是黄河水质安全的科技需求及提高灌区农业清洁生产水平的重要保障,具有重要的科学研究价值和现实意义。本研究立足河套黄灌区基本的农田生产现状,以消减农田生产中的特征污染物负荷为目地,针对内蒙河套灌区小麦向日葵间作,探索农田氮磷合理减量关键技术,揭示不同施肥强度下土壤养分含量与养分流失量之间的关系、研究不同施肥强度N、P养分源在土体、地下水中淋失时空分布及施肥强度与养分流失的相关性,提出清洁生产施肥标准体系,为制订面源污染物有效防治措施提供理论和实践依据。论文主要成果如下:不同施肥水平对间作作物的肥料效应及利用效率的试验研究表明, N₂P₂K₂处理能够显著提高作物的产量及肥料利用率,满足小麦向日葵间作对氮肥的需求,有效降低肥料在土体中的流失。田间淋溶水中TN、TP运移规律研究表明,TN、TP一水后最高,秋浇后最小;N₃及习惯施肥水平易造成土体中氮素流失;各次灌水后,向日葵区产生的氮素流失大于小麦区,TP变异系数相差不大。土壤原状土中TN、TP运移规律研究表明,N₃P₂K₂处理对小麦区、向日葵区造成较大的氮素流失;施用磷肥过多及过少都不利于作物对氮肥的吸收,易造成土壤氮素流失。当地习惯施肥及N₂P₃K₂处理易造成磷肥的流失。小麦向日葵间作条件下土壤硝态氮残留影响研究结果表明,小麦收获后,小麦区40～60cm土层N₂P₂K₂、N₃P₂K₂、N₂P₀K₂、N₂P₁K₂、N₂P₃K₂及习惯施肥处理产生明显的硝态氮累积现象;习惯施肥及N₃P₂K₂处理易造成土体中硝态氮的流失,N₂P₂K₂处理能有效提高作物对硝态氮的吸收效率。向日葵收获后,向日葵区120～160cm土层中当地习惯及N₃P₂K₂、N₂P₀K₂水平的土壤硝态氮含量明显大于其余施肥水平,易造成硝态氮流失进入地下水。肥料效应模型模拟合结果表明,适合河套灌区的小麦向日葵间作清洁施肥建议为,小麦最佳施肥量:N 69.79 kg/hm²,P 38.28 kg/hm²,K 32.17 kg/hm²,小麦区最佳施肥量比值为N:P:K=2.2:1.2:1;向日葵最佳施肥量:N 76.77 kg/hm²,P 43.41 kg/hm²,K 31.61 kg/hm²,向日葵区最佳施肥量比值为N:P:K=2.4:1.4:1。更多还原

【Abstract】 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.更多还原