Eragrostis curvula cultivars improve soil bacterial diversity, extracellular enzyme activities, and nutrition in grassland ecosystem soils

Research on Eragrostis curvula has focused primarily on its value for pastures and as a potential food source, while the contribution of its cultivars to soil nutrient cycling in nutrient-poor grassland ecosystems is still poorly understood. In this study, we assessed the effects of E. curvula cultivars on soil bacterial communities, enzyme activities, and soil properties in grassland soils. Soil samples were analysed for nutrient concentrations, pH, and enzyme activity. Pot trials with E. curvula Ermelo and Agpal cultivars were conducted over four months in a greenhouse. Pre- and post-harvest soils were assessed for changes in nutrient profiles, enzyme activities, and bacterial communities. There was an increase in the bacteria isolated from post-harvest soils compared to pre-planting soils. Soil growing the cultivars showed a significant increase in the nitrate reductase activity across all study sites. Soil N concentrations and pH increased in all post-harvest soils. The pearson correlation coefficients between soil enzymes and nutrients showed that alkaline phosphatase, acid phosphatase and glucosidase were moderately positively correlated with phosphorus (r = 0.41, 0.40, and 0.40 respectively) and negatively correlated with pH (r= -0.33, -0.32 and - 0.34 respectively). A weak positive correlation was observed between nitrate reductase and soil nitrogen (r = 0.22). These findings highlight how E. curvula cultivars shift the microbial profile over time while increasing N and pH in grassland ecosystem soils.