冻融条件下沙丘土壤水分物理性提升的试验研究

Hydraulic Lift of Sand Soil Water During Freezing and Thawing

基于乌兰敖都试验站内土壤冻融试验,探讨不同外界条件下土壤冻融作用对土壤中水分迁移的影响。结果表明:土壤冻结作用可以增加水分的迁移量,从而提高冻融层土壤水分含量,0-30cm和100-140cm深度土壤中水分迁移受冻结作用的影响比较显著,分别迁移了87.6,210.9mm,30-60cm和60-100cm深度受到的影响较小;冻融期内,稻草覆盖减小了水分向土壤上层迁移或者向下层的入渗;初始地下水埋藏较深能导致土壤水分迁移量变大。通过探究土壤冻融对水分物理性提升的影响作用,测定其提升数量,合理利用其提升的水分,改善固沙植被区浅层土壤水分条件,有利于固沙植物的生长和其他植物物种的侵入,提高固沙植被区的物种多样性,建立持久稳定的固沙植被。

Based on soil freezing and thawing experiment in Ulan＇aodu station, the influence on soil migration during freezing and thawing under different conditions was discussed. The results showed Soil freezing could increase the water content of soil freeze-thaw layer through increasing the amount of water water migration, the water content in 0--30 cm and 100--140 cm were affected more significantly by soil freezing with 87.6, 210.9 mm, respectively, whereas the water content at depth of 30--60 cm and 60--100 cm were less affected. During soil freezing and thawing, straw mulching not only decreased the soil water migration to the upper layers, hut decreased the soil water infiltration into the lower layers. The deeper initial groundwater level could make the soil water migration become larger. This study aimed to investigate the influence of soil freezing and thawing on the soil water hydraulic lift and the amount, so that the authors could make full use of that part of water to promote the soil water condition in the fixed-plant area. Therefore, this method not only contributes to the growth of sand-fixation plants and the intrusion of the other plant species, but improves species diversity in sand-fixation plant area, which could establish lasting and stable fixing vegetation.