Root Consolidation Mechanism Of Medicago Sativa L.in Early Stage Of Soil Bioengineering

Soil bioengineering is a set of environmental engineering technologies aiming to reduce erosion and improve habitat,scientifically repair and control soil erosion.For the study of soil bioengineering,early drawing solid earth resistance of the plant to grow a year of alfalfa as the research object,explore the essential characteristics of soil bioengineering alfalfa root system,analysis of soil bioengineering alfalfa root drawing force and the influence factors of tensile resistance,discusses the difference between ecological ridges for soil bioengineering in gully and slope soil bioengineering grass-embedded brick ramp.In order to provide excellent theoretical support for soil bioengineering technology.This paper draws the following conclusions:(1)The diameter and biomass of alfalfa roots decreased with the increase of growth depth,and the implementation of soil bioengineering would affect the growth strategy of plant roots.The root mass density and water content of alfalfa roots under soil bioengineering treatment were more evenly distributed than those in the untreated ground.(2)The factors influencing the vertical pulling force of soil bioengineering roots were explored.The vertical pulling force was positively correlated with root biomass,total root length,and ground diameter.With the increase of root water content,the vertical pulling force per plant showed a trend of first increase and then decreased,and reached the peak value when the water content was 75 ～ 80%.(3)Under the study of soil bioengineered alfalfa root tensile resistance,the root of alfalfa in the 0 ～ 20 cm shallow soil has a significant average tensile resistance,root maximum tensile resistance and root diameter were positively correlated,root maximum tensile strength and diameter showed a negative exponential power function relationship.The root of alfalfa treated by soil bioengineering had stronger fracture resistance,and its average maximum tensile strength and tensile strength were greater than those of alfalfa roots in the untreated ground.(4)The root characteristics of the two-soil bioengineered alfalfa were different.The furrow soil bioengineered ecological ridges had more fine roots with a diameter of 0 ～ 1 mm,and the total root length was the largest,but the mass density of coarse roots was low,which had little effect on soil strength improvement.However,the root mass density,biomass,and water content were distributed more evenly in the slope bioengineered grass-embedded brick slope,and the roots growing in the soil layer below 20 cm had better mechanical strength.In conclusion,soil bioengineering treatment changed the growth and distribution of alfalfa root system,which resulted in more fine roots and stronger fracture resistance under soil bioengineering treatment.From the actual situation of Xuanhua district,the slope soil bioengineering grass-embedded brick ramp has a good effect on the local soil and water loss.This study has an in-depth understanding of the effect and mechanism of soil fixation in the early stage of soil bioengineering,compared two different soil bioengineering methods,revealed the effect of soil fixation of plant roots,and combined the theoretical research of soil bioengineering with practice,in order to provide a theoretical basis for ecological restoration and soil and water conservation in the future.