Comparison of Infiltration Capacity Between Grassland of Different Time Lengths of Abandonment and Sea Buckthorn Land in Inner Mongolia

Abstract

[Objective] The effect of different vegetation covers on soil infiltration capacity in Inner Mongolia was analyzed in order to provide a theoretical basis for ecological restoration and vegetation allocation of the region. [Methods] Three ages of abandoned grassland (13 years, 25 years, and 30 years) and 13 years of sea buckthorn land in this region were used as treatments. The disc infiltration method and soil water characteristic curves were used to compare differences in soil hydraulic conductivity, soil macroporosity, and macropore connectivity. [Results] ① Soil infiltration capacity was positively correlated with the length of abandoned years, and became stronger as the number of abandoned years increased. The stable infiltration rate of soil followed the order of 30-year abandoned grassland > 25-year abandoned grassland > 13-year abandoned grassland > 13-year sea buckthorn land. ② Macroporosity and macropore connectivity followed the order of 30-year abandoned grassland > 25-year abandoned grassland > 13-year abandoned grassland > 13-year sea buckthorn land. Soil macropores accounted for 0.0004%—0.0034% of the soil volume and accounted for 44.35%—86.92% of the soil saturated infiltration rate. ③ The content of water stable aggregates >0.25 mm was the main factor affecting soil infiltration rate. [Conclusion] Abandonment improved the infiltration capacity of grassland, and the infiltration capacity increased with increasing number of years of abandonment. The infiltration capacity of abandoned grassland was greater than that of sea buckthorn land having the same number of years of abandonment. The main influencing factors were the number and connectivity of soil macropores, and water stable aggregates >0.25 mm.

Keywords

• soil infiltration rate
• macro porosity
• macropore connectivity
• abandoned grassland
• sea buckthorn land