Ecological Effect Of The Recycled Water Irrigation

This research is based on the investigation of Beijing reclaimed water current utilization situation, chooses the Beiyechang irrigated area in Daxing District as research object, which has utilized reclaimed water for about 3 years, using combination method of field survey and study, field test index and sample at fixed point, to give comprehensive evaluation of used reclaimed water quality and then confirm detailed soil environment research index and crop growth index, study the influence of soil environment and crop output and quality made by the reclaimed water irrigation and carry on the feasibility analysis of irrigation of agricultural land with reclaimed water.The analysis result of water quality to the reclaimed water shows that reclaimed water needn't consider the content of heavy metal, compared with the local groundwater, its nitrogen and phosphorus' content is far higher, the nutriment content is relatively higher. If using reasonably, it can increase soil fertility and bring increasing production. Its PH value and percentage of salt is higher, among which the sodium salt and magnesium salt are comparatively outstanding, water alkalescence is relatively heavier, which should consider much utilization bringing the soil salt alkaline problem.The research of reclaimed water irrigation influencing the soil environment indicates that the nitrogen, phosphorus, potassium content in reclaimed irrigation area soil is higher than the content in groundwater irrigation area, the soil fertility in reclaimed irrigation area improves more obviously than in groundwater irrigation area, nitrogen, phosphorus and potassium has accumulated in various degrees in the soil of top layer. The soil moisture content and temperature in early spring is higher in reclaimed water irrigation farmland fields, which is extremely favorable to the growth of wheat. The total salt content, sodium adsorption ratio and electric conductance are all higher in reclaimed water irrigation area soil layer than in groundwater irrigation, the soil salinity has accumulated in a certain degree.The research of reclaimed water irrigation influencing the crops indicates that wheat grows relatively bloom in reclaimed water irrigation area, but seed ripe rate is smaller than the irrigated area of groundwater, and utilization of reclaimed water irrigation can cause crops unfavorably-delayed senescence and late-maturing. The nitrogen content and phosphorus...