Influence of grazing intensity and regime on soil nitrogen fixation dynamics in alpine grasslands

Abstract

The present study was conducted to investigate the influence of grazing intensity and management regimes on
soil nitrogen cycling and related ecosystem processes in alpine grasslands. Rotational grazing (RG), characterized
by alternating short grazing periods at high stocking densities with rest intervals, has been proven to be a practice
that enhances herbage production and improves grassland resilience compared to continuous grazing (CG). Our
results showed that Proteobacteria are the main ANF phylum under all grazing levels. Grassland sowing is a
primary restoration means for heavily degraded alpine meadows on the Tibetan Plateau, but much less information
is known about soil nutrient dynamics under such grazing regimes. This study evaluated topsoil nutrient levels
(phosphorus, potassium, and nitrogen) and physical properties under three grazing intensities: light, moderate, and
heavy. It was concluded that increasing grazing intensity elevated soil organic matter, temperature, and nutrient
concentrations (nitrogen, potassium, and phosphorus) while reducing soil pH and water content. These findings
demonstrate that intensity and regime of grazing significantly influence dynamics in soil nitrogen fixation
processes.