In nature, plants cannot grow without soil biota such as fungi and bacteria. Successful plants are able to harness positive, growth-promoting soil organisms while avoiding the negative effects of others. Which plant traits can predict these interactions, or the success of a plant? Researchers and plant breeders would like to know. In a paper in the Journal of Ecology of August 24, a team from the Netherlands Institute of Ecology (NIOO-KNAW), Wageningen University and the Universität Leipzig tested exactly this and found thick roots to be a leading trait.