Variations in soil functioning of grasslands along a management gradient

Agriculture in Europe is moving toward greater sustainability along two main paths: continued intensification supported by new technologies, and an increasing shift toward less intensive approaches. The latter is expected to improve soil abiotic and biotic properties and, thereby enhancing soil functioning. Yet the underlying mechanisms remain poorly understood under on-farm conditions. We examined how management intensity influences soil abiotic attributes, microbial communities, and processes related to nutrient cycling along a locally constrained gradient of permanent grasslands (within a 12-km radius). Farmer surveys on management practices were combined with measurements of soil organic carbon (SOC), pH, bulk density, nitrogen, bacterial and fungal communities, and three complementary indicators of organic matter degradation: litter decomposition, extracellular enzymatic activity, and evenness of substrate utilisation). Management intensity significantly altered fungal community composition. SOC increased significantly with reduced management intensity and was strongly correlated with decomposition rates and fungal community composition, suggesting a central role of fungal-driven processes in organic matter stabilisation. In contrast, TEA was not linked to management intensity but was primarily governed by abiotic factors, especially soil pH. ESU showed no clear response to management but was associated with bacterial community composition. These divergent patterns highlight that different soil processes are controlled by distinct drivers and cannot be captured by a single proces. Our results demonstrate that local-scale management decisions influence soil processes through complex and non-linear pathways shaped by both abiotic and biotic factors. These findings underscore the importance of multi-proces approaches and context-sensitive management strategies to support sustainable grassland use.