Soil biocatalysts as Indicators of Soil Health in Grassland Ecosystem

Soil enzymes act as natural biocatalysts that regulate the transformation of organic matter into plant-available nutrients, playing a central role in sustaining soil fertility and ecosystem function. Understanding these enzymatic processes is essential for advancing sustainable agricultural practices and aligning soil management with the principles of green chemistry. This study investigates extracellular soil enzyme activities across grassland ecosystems in four zones of Northern Ireland, comparing hedgerow soils with adjacent agricultural fields. Activities of carbon-, nitrogen-, and phosphorus acquiring enzymes were quantified and analysed alongside soil physicochemical parameters. Hedgerow soils exhibited significantly greater variability in enzyme activity compared with field soils, highlighting the influence of landscape features and land management on microbial functionality. Strong positive correlations were observed among nutrient-acquiring enzymes, indicating tightly coupled carbon, nitrogen and phosphorus cycling within soil microbial communities. Eco-enzymatic stoichiometry indicated that microbial communities were primarily limited by carbon and phosphorus, while nitrogen was relatively sufficient. These findings demonstrate how enzyme-based biocatalytic processes underpin soil health and nutrient cycling, providing valuable insights for sustainable land management and the development of greener agricultural systems.