Effects of cover crops on soil biota, soil fertility and weeds, and Pratylenchus suppression in experimental conditions

Cover crops are used in Mediterranean agrosystems to reduce soil degradation and restore soil function. We carried out an experiment to test the effects of two cover crops (Brachypodium distachyon and Trifolium subterraneum, mulched or incorporated) and two bare soil controls (fertilised and unfertilised) on soil properties, biodiversity, and soil natural suppressiveness against Pratylenchus neglectus in pot microcosms. Cover crop performance, weed infestation, litter decomposition rates, soil properties, and the response of soil biota (nematode indicators, mesofauna feeding activity, enzymatic activity, and mycorrhizal spores) were measured. A shortterm suppressiveness experiment was performed to determine P. neglectus colonisation of wheat roots after each treatment. Trifolium subterraneum incorporation significantly enhanced the fungal-mediated decomposition channel and decomposition rates, but enzymatic activities and mycorrhizal spore abundances did not respond to the experimental treatments. Cover crops were effective at controlling weeds, but did not increase soil suppressiveness against P. neglectus. Brachypodium distachyon cover cropping increased root infection.