Plant-soil feedback and crop rotation

Plant-soil feedback (PSF) can be a major driver of plant performance in communities, and this concept can be used in selecting crop rotation sequences to maximize agricultural yields. Potential benefits of using PSF in this context include nutrient use optimization, pathogen reduction and enhancement of mutualisms between crops and microbes. Yet, the contributions of these combined mechanisms are poorly understood. Here we investigated the relative contributions of these mechanisms using five major crops commonly cultivated in rotation (alfalfa, canola, maize, soybean and wheat) under controlled conditions. We trained soil by growing each of the five crops in a ‘training phase’, and then reciprocally planted the five crops in the trained soils in a ‘feedback phase’. To tease out soil biota from nutrient effects, we established three treatments: ‘control’ (trained unsterilized soil used in the feedback phases), ‘biota’ (sterilized soil in the feedback phase inoculated with soil biota fro...