压砂地不同砂土混合比下土壤水分蒸发动态研究

Dynamic Research on Soil Water Evaporation under Different Sand Mixing Ratio in Pressed Sand Land

为了研究不同砂土混合比覆盖下对土壤蒸发的影响,通过田间土柱基础实验,采用微型蒸渗仪测定水分蒸发变化。试验采用完全试验,选取降雨量、砂土混合比两个因素,各五水平处理,即设置5个模拟降雨量(6、9、12、15、18 mm)和5种砂土混合比例(0%、25%、50%、75%、100%)的土壤蒸发试验。研究结果表明:同一砂土混合比处理的土壤,随着模拟降雨量(试验灌水量)的增加土壤体积含水率略有增加,不同灌水量处理的土壤体积含水率随土层深度的变化趋势基本相同;与裸土相比,土壤覆砂能够大幅度减少土壤水分蒸发,砂土混合比25%、50%、75%、100%(全覆砂)处理的土壤比裸土(砂土混合比0%)的累积蒸发量分别减少5.4%、21.0%、36.2%、45.3%;砂土混合比越大,土壤日蒸发量和累积蒸发量越小,砂土混合比为100%的抑制蒸发效果最好。砂石覆盖可以有效抑制土壤水分蒸发,并且这种抑制作用强弱与砂土混合比密切相关。研究结论可为中国旱区农田砂石覆盖实践提供必要的指导,为提高压砂地水资源高效利用和可持续发展提供数据支撑。

In order to study the effect of different sand mixing ratio on soil evaporation,a micro-infiltrator is used to measure the water evaporation in a field experiment.A complete test is adopted in the test,and two factors,rainfall and sand mixing ratio,are selected,and each of the five levels is treated.That is,five simulated rainfalls(6mm,9mm,12mm,15mm,18mm)and five kinds of sand mixing ratios are set(0%,25%,50%,75%,100%)soil evaporation test.The results show that the soil moisture content of the soil treated with the same sand mixing ratio increases slightly with the increase in simulated rainfall(test irrigation amount),and the soil water content with different irrigation amount changes with the depth of the soil layer.Compared with bare soil,soil sand-covering can greatly reduce the evaporation of soil moisture.The sand mixing ratio is 25%,50%,75%,100%(full sand).The soil is treated with bare soil(sand mixture ratio is 0%).Cumulative evaporation has decreased by 5.4%,21.0%,36.2%,45.3%,respectively.The larger the sand mixing ratio,the smaller the daily evaporation and cumulative evaporation of the soil,and the sand mixing ratio of 100%is the best to suppress evaporation.It shows that sand and gravel covering can effectively inhibit the evaporation of soil moisture,and this inhibition is closely related to the sand mixing ratio.The research conclusions can provide a necessary guidance for the practice of sand and gravel cover in the arid regions of China,and provide data support for improving the efficient utilization and sustainable development of water resources in the sand control areas.