Decomposing cover crops modify root-associated microbiome composition and disease tolerance of cash crop seedlings

The assembly of root-associated microbes during the seedling stage has strong impact on subsequent performance of crops. Major factors influencing this assembly are crop species identity and composition of potential root-colonizing microbes in the bulk soil. The latter can be modified by soil management, such as organic amendments. The incorporation of residues of cover crops before the start of the growing season of cash crops presents an interesting option for steering of root-associated seedling microbiomes as there is a wide range of cover crops species with different properties available for farmers.
In a greenhouse study, we examined the effect of soil amendments with milled shoot and root materials of seven cover crop species (niger seed, phacelia, rapeseed, radish, vetch, black oat and buckwheat) on the soil nitrogen and biomass of seedlings of four cash crop species (asparagus, carrot, onion and sugar beet) and their root-associated bacteria and fungi. Field-grown cover crops m...