Study On Crop Growth And Nitrogen Transport Under Sewage Irrigation

With the severe shortage of water resource on the world, development of sewage resource was paid more attention socially.In order to use it safely and high efficiently, and ensure agriculture sustainable development, further research of sewage irrigation technology research is particularly important. This study is primarily based on barrels experiment to study the laws of nitrogen transport and transformation, the impact of change of the K, Na, Ca, Mg content in the soil, and the crop physiologic index under different kinds of irrigation water quality and quantity condition. Through analysis, the following conclusions were drawn:1, Sewage, diluted sewage, renewable water,which all affect the the absorption of winter wheat seeds to N, P, K and the winter wheat production, contrasting with clear water irrigation. Water quantity and quality have a remarkable effect on nitrogen content in wheat seeds and wheat production. Water quality has a remarkable effect on phosphorus content and Water quantity has a remarkable effect on potassium content. Nitrogen content is high with sewage irrigation, and potassium content is high with diluteed sewage irrigation, sewage irrigation can increase winter wheat production.2, Irrigating water quota has a remarkable effect on leaf area and plant height. Higher irrigating quota of sewage, diluted sewage, renewable water can enhance leaf area and plant height growth significantly.Diluted sewage, renewable water can enhance the summer corn production.3 , After crop harvest, Salt content increased in the soil, the increase of salt in the soil is primary correlation to irrigating quota and the content of ion in the irrigation water. The more irrigation quota, the more salt accumulation in the soil. Under the same water quality irrigation condition, the addition salt in the soil of higher irrigation quota is larger than that of corresponding lower irrigation quota.4, The concentration of NH₄⁺—N in the soil surface is in the higher state, Which affected by the NH₄⁺—N in the irrigation water, after two days of irrigation. When the water quality is the same , the peak of concentration of NH₄⁺—N in the surface soil is that the higher irrigation quota is larger than that of lower corresponding low irrigating quota . When the irrigating quota is the same, the peak of concentration of NH₄⁺—N in the surface soil is : Sewage> diluted sewage , renewable water , clear water, It accorded with that amount of NH₄⁺—N fertilized into the soil. NO₃^- - N is a major form of crop nitrogen absorption, NO₃^- - N prone to eluviation in the soil. NO₃^- - N is consistent with different treatment in the soil along the profile changes, NO₃^- - N content increased gradually from the surface to the bottom, it indicate that the NO₃^- - N has a clear tread washing downward.