Facilitating the Restoration of Disturbed Meadow Soils Using Modified Organic Materials in the Qinghai–Tibet Plateau

Abstract

As host to among the most fragile ecosystems globally, the Qinghai–Tibet Plateau is experiencing considerable ecological degradation. This study investigated the effects of modified organic materials (MOM) on restoring disturbed meadow soils in the Qinghai–Tibet Plateau. The results showed that soil water content decreased with disturbance and was increased through MOM addition by 10.86%, 5.85%, 15.20%, and 90.58% in non-disturbed, lightly disturbed, moderately disturbed, and severely disturbed soil, respectively. The soil acidity significantly increased with disturbance and significantly decreased in severely disturbed soil after restoration. Disturbance increased soil organic carbon (SOC) levels, while MOM application decreased SOC content in lightly (47.74%), moderately (30.53%), and severely disturbed soil (78.55%), but increased it in non-disturbed soil (120.86%). Moreover, activities of enzymes related to the nitrogen and phosphorus cycles decreased with disturbance but increased after restoration. In addition, the microbial communities varied with disturbance. The increase in soil water content and pH following MOM addition increased microbial community abundance. Thus, MOM addition promoted plant growth primarily by enhancing soil water content, reducing soil acidity, and promoting SOC decomposition, which further promoted soil nutrient cycling and improved the microbial community structure.