Roots of Cleistogenes songorica Improved Soil Aggregate Cohesion and Enhance Soil Water Erosion Resistance in Rainfall Simulation Experiments

Abstract

Native grasses that have acceptable forage yield and quality can play an important role in the sustainable development and protection of soil ecosystem. In this study, we investigate a native grass of northern China, Cleistogenes songorica, showing promise for erosion control. We used a rainfall simulation method to compare the effects of C. songorica roots and tall fescue roots (Festuca arundinacea) on soil erosion in sandy loam field plots with irrigation during establishment in 2011 and under mild or severe drought treatments in 2012 and 2013. Root length (RL), root diameter (RD), soil bulk density (SBD), soil field capacity (FC), sediment yield (SY), and root biomass (RB) of each soil monolith were sampled in the topsoil layer (0–10 cm) with a rectangular geotome. The proportion of stable aggregates in soil and the soil anti-scouring properties were also evaluated. C. songorica had higher RD than tall fescue throughout the experiment and evolved higher RL and RB by 2013. Both C. songorica and tall fescue enhanced the erosion resistance of soil, but C. songorica stabilized soil more effectively than did tall fescue. The proportion of stable soil aggregates was greater in C. songorica plots than in tall fescue grassland under mild drought. The present study shows that C. songorica has great potential to be one of the biological resources for soil erosion resistance, water and soil conservation in arid and semi-arid areas.