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采用室内土柱模拟试验,研究了不同覆砂厚度条件下土壤潜水蒸发及蒸发后盐分(EC)分布特征,并就覆砂厚度对土壤水盐运移的影响进行了分析。结果表明:覆砂厚度对潜水蒸发的抑制率有显著效果,且抑制率随覆砂厚度的增加而升高,如当覆砂厚度1.7 cm时抑制率达到83%,当覆砂增加到3.6 cm和5.7 cm时,抑制率分别为95%和97%;土壤表层覆砂具有显著的抑盐效应,通过覆砂明显的减轻了土壤盐分向上运移和表聚,如当覆砂厚度1.7 cm时,表层盐分抑制率达到83%,当覆砂厚度为3.6 cm与5.7 cm时,盐分抑制率则分别上升到96%和97%。本试验表明,土壤表层覆砂是一种防止土壤水分蒸发,提高土壤保水能力和抑制土壤盐分表聚的有效方法,覆砂厚度达到3.6 cm是一种在新疆北疆绿洲合理覆砂厚度。
The indoor soil column simulation test was used to study the distribution characteristics of soil submersion evaporation and evaporation (EC) under different sand cover thickness. The effects of sand cover thickness on soil water and salt transport were also analyzed. The results showed that the sand cover thickness had a significant effect on the inhibition rate of submersion evaporation and the inhibition rate increased with the increase of sand cover thickness. For example, when the sand cover thickness was 1.7 cm, the inhibition rate reached 83%. When the sand cover increased to 3.6 cm And 5.7 cm respectively, the inhibition rates were 95% and 97%, respectively. The surface sand-mulching had significant salt suppression effect. The salinity migration and surface aggregation were significantly reduced by sand mulching. For example, when the sand mulching thickness was 1.7 cm , The surface salt inhibition rate reached 83%. When the sand coverings were 3.6 cm and 5.7 cm, the salt inhibition rates increased to 96% and 97%, respectively. The experiment shows that sand covering of soil surface is an effective method to prevent soil water evaporation, improve soil water retention capacity and inhibit soil salinity aggregation. The sand cover thickness of 3.6 cm is a reasonable sand cover thickness in the northern Xinjiang oasis.