Soil microorganisms are central to the provision of food, feed, fiber, and medicine. Engineering of soil microbiomes may promote plant growth and plant health, thus contributing to food security and agricultural sustainability (1, 2). However, little is known about most soil microorganisms and their impact on plant health. Disease-suppressive soils offer microbiome-mediated protection of crop plants against infections by soil-borne pathogens. Understanding of the microbial consortia and mechanisms involved in disease suppression may help to better manage plants while reducing fertilizer and pesticide inputs.