辽西低山丘陵区坡地砾石量及粒径对土壤水分蒸发影响的模拟试验研究

【目的】分析砾石量及粒径对土壤蒸发的定量影响。【方法】以辽西低山丘陵区坡地非砾石土壤为对照(CK),通过设置4种粒径和6种砾石量的含砾石土壤,采用室内恒温蒸发模拟研究砾石量和粒径对土壤水分蒸发的影响。【结果】2～5 mm粒级砾石量在30%范围内均能减少蒸发,当粒径大于2～5 mm时,较低的砾石量并不能减少土壤累积蒸发量,甚至增大土壤累积蒸发量,当砾石量大于15%时土壤累积蒸发量随砾石量的增大显著减小;当砾石量较小时,小粒径的土壤累积蒸发量较小,随土壤中砾石量的增加,土壤累积蒸发量随着砾石粒径的增大而减小;含砾石土壤平均蒸发速率均小于非砾石土壤,初始蒸发速率表现为含砾石土壤大于非砾石土壤,且随砾石量的增大表现为增大趋势。【结论】砾石能够显著的降低土壤蒸发量。

Simulation Test of the Influence of Gravel Content and Particle Size on Soil Moisture Evaporation in Hilly Region of Western Liaoning Province

【Objective】Analyze the quantitative effect of gravel content and particle size on soil evaporation.【Method】In this paper, we set six different levels of gravel and four kinds of particle sizes, with homogeneous soil as contrast, and then, study the influence of gravel content and particle size on soil moisture evaporation by indoor constant temperature evaporation simulation experiment.【Result】The gravel content of particle size 2～5 mm can reduce the evaporation in the range of 30%, lower gravel content does not reduce soil accumulated evaporation and even increase when the particle size was larger than 2～5 mm, but the accumulated evaporation of soil decreases with the increase of gravel content when the gravel content was greater than 15%; the cumulative evaporation of small particles was smaller when the gravel content was small. With the increase of gravel content,the accumulated evaporation of soil decreased with the increase of particle size. Besides, the average evaporation rate of gravelly soil was less than that of homogeneous soil, while the initial evaporation rate of gravelly soil more than homogeneous soil and showed increased trend with the increase of gravel content.【Conclusion】Gravel could significantly reduce soil evaporation.