Legume Grasslands Promote Precipitation Infiltration better than Gramineous Grasslands in arid Regions.

Precipitation infiltration is the most important process for soil water supply of vegetation in the arid regions. Higher infiltration rate is advantageous for vegetation growth and maintenance in the arid areas. Four grassland types ( Medicago sativa, Agropyron cristatum, Caragana korshinskii and Stipa capillata) were selected in this study. Results showed that the infiltration capacity in the legume grasslands was about 30% higher than in the gramineous grasslands and the difference was significant ( p < 0·05). Furthermore, the infiltration rate in legume shrub-grassland was 16% less than the legume grasslands, but the difference was not significant ( p > 0·05). The below-ground biomass, total porosity, capillary porosity, soil organic matters and soil aggregate were the main factors to determine the soil infiltration rates. The capillary porosity and soil aggregate of the top soil presented significant negative effects on soil infiltration rate ( p < 0·05). The below-ground biomass in 10-30 cm soil layer was the most important factor, which significantly and positively correlates with the soil infiltration rate ( p < 0·01). It is possible to conclude that the legume grasslands presented the higher soil infiltration rate and promoted precipitation infiltration in the studied area. And the legume grasslands might be a more suitable option for vegetation restoration from the perspective of soil infiltration and water supply in the arid regions. Copyright © 2016 John Wiley & Sons, Ltd. [ABSTRACT FROM AUTHOR]