Disturbance reduces the moss‐dominated biocrust inhibition on infiltration and improves soil moisture storage within the Loess Plateau, China

Abstract

Various factors influence biocrust effects on infiltration and soil moisture. On China's Loess Plateau, well‐developed moss‐dominated biocrusts reduce infiltration and suppress shrub growth, however, the interrelationships between rainfall conditions and disturbance management to alleviate these impacts are unknown. In a semiarid watershed on the Loess Plateau, we applied two forms of disturbance, scarification (controlled harrowing) and compaction (simulated grazing), at four intensity levels (control‐intact, light, moderate, and heavy) to well‐developed moss‐dominated biocrusts and a bare soil (BS) for comparisons to form eight treatments with three replications. Rainfall intensity and depth, soil moisture, run‐off, and sediment yield were measured during the rainy season (July–October). In total, well‐developed biocrusts did not significantly affect infiltration but reduced soil moisture at depths of 120–180 cm (p < 0.05), and disturbance increased infiltration and deep soil moisture beneath biocrusts (p < 0.05). Rainfall conditions changed the effects of biocrusts and disturbance. Under long, low‐intensity rainfall, moss‐dominated biocrust infiltration was slightly greater than BS, but scarification increased infiltration and compaction reduced it (p < 0.001). Under short, high‐intensity rainfall, biocrusts reduced infiltration, and disturbance intensity increased infiltration and sediment yields (p < 0.001). Light grazing or using light or moderate scarification improves well‐developed moss‐dominated biocrust infiltration in the pastures during May–June before the rainy season during July–October on the Loess Plateau, while avoiding increased soil erosion.