Effects of plant roots and arbuscular mycorrhizas on soil phosphorus leaching

While the impact of arbuscular mycorrhizal fungi (AMF) on phosphorus (P) uptake iswell understood, themechanism(s) of howthese fungi affect P leaching fromsoil is still unclear. Herewe present results of a study inwhich we grew a mycorrhiza-defective tomato (Solanum lycopersicum L.) genotype (named rmc) and its mycorrhizal wild-type progenitor (named 76R) in microcosms containing non-sterile soil, to examine the influence of roots and AMF on P leaching. More Pwas leached fromthe plantedmicrocosms as compared to the plant-free controls. Further, although there was more plant biomass and greater P uptake in the mycorrhizal plant treatments, these treatments were associated with the most leaching of total P, reactive P, and dissolved organic carbon (DOC). There was a strong correlation between the total P and DOC leached, suggesting that root and fungal exudates may have affected P leaching. These findings provide new insights into the impact of roots and AMF on nutrient leaching in soils. (C) 2020 Elsevier B.V. All rights reserved.