Understanding biological measurement of Soil Health

Increasing anthropogenic activities such as urbanization or intensive agricultural practices put strong pressure on soils and lead to degradation and loss of biodiversity. Soil health monitoring is high on the agenda of the European Commission with the ambition to restore or maintain soil health in 75% of soils across Europe by 2030. Therefore, the assessment depends on a reliable cost-effective framework for measuring soil health. Current soil health monitoring systems are, in many cases, applying a traditional minimum soil dataset approach focused on key agronomic soil chemical indicators, with a few easy-to-measure but not very informative soil biological and physical measurements. Hence, understanding the role of soil biota and quantifying their contribution to soil processes is crucial to make analyzing soil biological properties more interpretable and useful for monitoring. Soil aggregation is a key parameter for soil sustainability. To explore the role of biological actors in forming stable aggregates in agricultural soils different management practices (tillage vs no-tillage, organic manure vs. mineral fertilizer, and strip cropping) will be assessed regarding their 1) soil structural properties and 2) their impact on the (functional) biodiversity in three well-replicated long term field experiments in Switzerland and The Netherlands. Based on these results, contribution of selected soil biota, i.e., enchytraeids, microbial communities, and plant roots to soil aggregation and macropore formation will be quantified in laboratory experiments. These findings will thereby help to develop a European soil health monitoring scheme and improve recommendations of management practices to support soil health.