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近年来,随着灌溉事业的发展,出现了由于灌溉造成土壤肥力下降以及土质恶化的现象,从而提出了“灌溉侵蚀”这一新的研究课题。例如在苏联的乌兹别克,由于灌溉侵蚀曾造成大面积农田的毁坏,使棉花减产30％。因此,有关部门对于灌溉侵蚀及其防治措施进行了大量试验研究工作。 苏联学者认为,在坡度大于1％～3％的耕地上均能发生灌溉侵蚀。在灌溉水流的冲刷力和拖曳力的作用下,面蚀,沟蚀及深层侵蚀均会发生,土壤中的腐殖质以及氮、磷随之流失,土壤肥力剧减。特别是当土层下
In recent years, with the development of irrigation business, the decline of soil fertility due to irrigation and the deterioration of soil quality have emerged. Therefore, a new research topic of “irrigation and erosion” has been put forward. In Uzbekistan, for example, in the Soviet Union, the erosion of large areas of farmland caused by erosion has caused a 30% reduction in cotton production. Therefore, the relevant departments conducted a lot of experimental research on irrigation and erosion control measures. Soviet scholars believe that irrigation erosion can occur on cultivated land with a gradient of more than 1% to 3%. Under the action of the scouring force and drag force of irrigation water flow, the surface erosion, gully erosion and deep erosion will occur. The humus, nitrogen and phosphorus in the soil will be lost and the soil fertility will decrease drastically. Especially when the soil layer