Green manure-induced shifts in nematode communities associated with soil bacterial and fungal biomes

Green manures are widely used to enhance soil health and suppress plant-parasitic nematodes, and their effects on the broader soil food web have been studied. Beyond direct suppression, the role of green manures in supporting and sustaining soil food webs has attracted increasing attention. In this study, we evaluated the use of DNA sequencing to identify various nematode genera and their microbial associates in a field trial using oat (Avena sativa) and hairy vetch (Vicia villosa) as green manures. Nematode index analysis revealed that the oat treatment promoted a structured nematode community. Furthermore, the nematode community structure observed in the oat treatment was linked to specific bacterial and fungal genera. Several beneficial fungi were identified, indicating that oats, used as a green manure, actively enhanced the microbiome. Our results showed that enriching the micro-food web through organic fertilizers can help in the detection of beneficial microorganisms, with the nematode index serving as a potential indicator.