Soil health increases primary productivity across Europe

The role of soil health in regulating primary productivity at large scale across different land-use types remains poorly understood. This hinders our ability to predict the impact of soil degradation on essential ecosystem services such as food provision and climate regulation. To address this gap, we conducted a pan-European observational field study using data from 588 sites and 27 countries to investigate the link between soil health (a composite index based on soil properties, biodiversity, and plant disease control) and primary productivity across three major land-use types: woodlands, grasslands, and croplands. We found that soil health in woodlands was 31.4% higher than in grasslands, and 76.1% higher than in croplands. We further observed that soil health was positively linked to cropland and grassland productivity at the continental scale. Woodland productivity was linked to climate conditions rather than to soil health status. We observed that soil organic carbon and the richness of Acidobacteria, Firmicutes, and Proteobacteria had a positive effect on primary productivity. Among microbial functional groups, we found that nitrogen-fixing bacteria and mycorrhizal fungi positively related to primary productivity in croplands and grasslands, while plant pathogens showed a negative relationship. Together, our results point to the importance of soil biodiversity and soil health for maintaining primary productivity across contrasting land-use types.