Plant roots have potential impacts on soil mineral weathering and leaching.Our objective is to understand the physical mechanisms of plant roots affecting weathering andleaching of loess soil. Root densities were measured through the method of a large-size dug profile,and transport fluxes of soil elements were determined using an undisturbed monolith soilinfiltration device on the hilly and gully regions of the Chinese Loess Plateau. The results showthat the improvement effects of soil environment by plant roots are mainly controlled by the densityand weight of the fibrous roots with the diameters less than 1 mm. Plant roots have the strongereffects on soil physical properties than chemical properties. The principal components analysis(PCA) indicates that soil physical properties by plant roots account for 56.7% of variations in soilenvironment whereas soil chemical properties and pH contribute about 24.2% of the soil variations.The roles of plant roots in controlling soil weathering and leaching increased in the followingorder: infiltration enhancement > increase of bio-active substance > stabilization of soilstructure. The effects of plant roots on soil mineral weathering and leaching can be quantifiedusing the multiple regression models with the high prediction accuracies developed in this study.
LI Yong1,2, ZHANG Qingwen1,2, WAN Guojiang3, HUANG Ronggui3, PIAO Hechun3, BAI Lingyu2 & LI Lu2 1. State Key Laboratory of Soil Erosion and Dryland Farming on the Loess Plateau, Institute of Soil and Water Conservation, Chinese Academy of Sciences, Yangling 712100, China
