五种护坡草本植物根系固土效果研究

对于公路边坡而言,植物根系在稳定土壤结构、提高土壤抗冲性、防治土壤侵蚀方面作用显著。为准确地评价植物根系的固土作用,选取北京地区常见的5种护坡草本植物,研究了其根系结构特征和根系强度特征,比较了不同草本植物根系结构的差异,结果表明:选取的草本植物根系生长深度除紫花苜蓿外多在0.6 m以内,沙打旺和狗尾草的根系总长度最大,表现出更好的抵抗拔出破坏的能力,而高羊茅和沙打旺根系在土壤中的数量较多,表现出更好的增强浅层土壤抗剪强度的效果。因此,北京地区的护坡草本植物,从根系固土的角度分析,沙打旺表现最好,其次是狗尾草、高羊茅和白三叶,表现较差的为紫花苜蓿。

Study on Soil Consolidation Effect of Five Kinds of Herbaceous Plants for Slope Protection

For highway slopes,plant roots play an important role in stabilizing soil structure,improving soil anti-scourability and preventing soil erosion. In order to accurately evaluate the soil consolidation effect of plant roots,the paper selected 5 common herbaceous plants for slope protection in Beijing,studied the characteristics of root structure and root strength and compared the difference of root structure of different herbs. The outcomes show that except Medicago sativa,the root growth depth of the selected herbs is less than 0.6 m,the total root length of Astragalus laxmannii and Setaria viridis are the largest,showing better resistance to pullout damage. The number of roots of Festuca elata and Astragalus laxmannii are more in the soil,showing better effect of enhancing the shear strength of shallow soil. Thus,analyzing from the angle of soil consolidation of root system,among the herbaceous plants for slope protection in Beijing,Astragalus laxmannii perform the best,followed by Setaria viridis,Festuca elata and Trifolium repens,and Medicago sativa is the worst.