Effects of Cover Crops on Soil Mesofauna in Horticultural Systems in Portugal

Soil is essential for human survival, with approximately 95% of global food production originating from land. However, over the past century, overexploitation has led to soil degradation and biodiversity loss, with significant impacts on agroecosystems. Portuguese agriculture faces diverse challenges, particularly in the horticultural sector, which occupies substantial territory and supports key economic chains. Consequently, indicators for assessing soil quality are crucial, with mesofauna serving as sensitive bioindicators due to their ecosystemic roles. Among sustainable practices, cover crops are believed to mitigate soil issues by enhancing the biotic functionalities. This study aimed to evaluate the impact of cover crops on soil biological quality in horticultural systems in Portugal. From 2022 to 2025, six horticultural fields in the Alentejo, Ribatejo, and Oeste regions were assessed, introducing cover-crops before main crops and comparing them to controls. Soil samples were collected during cover and main crop presence; mesofauna was extracted via Berlese-Tullgren funnels and classified under the QBS-ar methodology. Results showed enhanced soil biological quality (p < 0.001) in cover crop plots compared to controls, with no significant differences across regions (p = 0.66) or crop types (p = 0.37), indicating the implementation of cover crops as the primary driver for enhanced soil health.