Evaluation of Hydro-Mechanical Properties and Root Architecture of Plants for Soil Reinforcement

Abstract

Plant helps to stabilize the masses of soil via hydrological and mechanical means. The effects of vegetation on soil depend on the overall root growth, architecture and its hydro-mechanical functions. Three leguminous plants, Leucaena leucocephala, Pterocarpus indicus and Peltophorum pterocarpum were evaluated in terms of their hydro-mechanical characteristics and root architecture for soil reinforcement. The results show that L. leucocephala exhibited the highest hydrological properties such as diurnal transpiration, water absorption capacity and soil matric suction (SMS). Regarding mechanical characteristics, L. leucocephala exhibited the highest root tensile strength and cellulosic components in the root. Interestingly, L. leucocephala also showed a higher root length, volume and tips than Pterocarpus indicus and Peltophorum pterocarpum . The SMS was strongly (r = 0.79) correlated with leaf area index (LAI), indicating that high LAI improved SMS. In conjunction with the cellulosic composition, root tensile strength of the species studied was highly correlated with the alpha-cellulose content (r = 0.9) and showed that high alpha-cellulose content of roots improved mechanical properties of plants to provide reinforcement in the soil. The highroot tensile strength, root cellulosic composition and VH-type root of L. leucocephala make the species special for growing as a soil reinforcing plant. In conclusion, L. leucocephala properties revealed that it possessed excellent hydro-mechanical properties and root architecture and can be planted on slopes for soil reinforcement.