Soil infiltration rate of forestland and grassland over different vegetation restoration periods at Loess Plateau in northern hilly areas of China

Abstract

Vegetation restoration practices play an important role in environmental management and could mitigate soil and water losses in the Chinese Loess Plateau. The main objective of this study was to ascertain the influence of vegetation durations on soil infiltration rate and other related soil properties. Undisturbed soil columns in triplicate from the same plot, with different locations, were collected to estimate the accumulated soil infiltration over different vegetation periods (9, 15, and 25 years) of grassland and forestland at different time intervals. The highest cumulative infiltration and wet front movement speed was recorded after 25 years of grassland and increased with the vegetation restoration duration. Low root biomass density (g cm−3) and soil organic matter (g kg−1) were recorded in the 9-year plantation of forestland and grassland; however, maximum root biomass densities of 1.614 ± 0.95 mg cm−3 and 0.938 ± 0.03 mg cm−3 were recorded after 25 years of forestland and grassland. Furthermore, root images scanner analysis showed that the 25 years of grassland has higher root length density and root surface area density of 5.917 ± 0.86 cm cm−3 and 2.058 ± 0.95 cm2 cm−3 at surface and subsurface soil layers. We therefore suggest that for revegetation periods of less than 25 years, grassland would be better for soil infiltration and related soil properties particularly in areas of the Chinese Loess Plateau.