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长期以来,在减少和克服旱灾的措施中,有许多是从抑制水分蒸发来考虑的。抑制水分蒸发的措施大致有两类: 一类是用农业技术措施来抑制土壤水分蒸发。这类措施主要是疏松表土抑制毛管水上升;用压实表土防止汽态水扩散。例如大寨的“海绵田”,西北地区的铺砂防旱。据调查研究,华北地区春季耙磨保墒措施,在土壤湿润的条件下,可减少农田土壤水分蒸发70%至80%;在表土干旱条件下可减少12%至18%。东北地区钉齿耙耙地,一般可抑制蒸发20%至40%。在灌溉条件下,也必须把用水和保水结合起来,才能更加有效。
For a long time, many measures to reduce and overcome drought have been taken into account in suppressing the evaporation of water. There are two general types of measures to suppress the evaporation of water: one is the use of agricultural techniques to suppress the evaporation of soil moisture. Such measures are mainly loose soil suppression capillary water rise; compacted topsoil to prevent the spread of steam water. For example, Dazhai’s “Tientian” sand dredging in the northwest. According to the investigation and research, spring rake mulberry preservation measures in North China can reduce 70% -80% of farmland soil water evaporation under soil wetting conditions and 12% -18% in surface soil dry conditions. Northeast rake tooth rake, generally inhibit the evaporation of 20% to 40%. Under irrigation, water and water must also be combined to be more effective.