Arbuscular mycorrhizal fungi reduce potassium, cadmium and ammonium losses but increases nitrate loss under high intensity leaching events

Abstract

Background: Nutrients and heavy metals can be lost from soils via leaching, and arbuscular mycorrhizal fungi (AMF) can influence these events. Soil column experiments were carried out to examine whether leaching intensity and AMF can alter nutrient and Cd uptake in white clover plants and the extent of their losses through leaching. Results: The presence of AMF significantly increased shoot and total biomass, as well as increased N, P, Cu and Zn uptake independent of water amount applied; while root P and Cu uptakes were promoted by AMF at any water amount treatments. Higher water amounts led to reductions in total N, K and Zn uptake for AMF-colonized plants in comparison to moderate water amount treatments. In the absence of AMF, white clover at low water amount treatment exhibited maximal root Cd uptake. At high water amount treatments, the presence of AMF significantly decreased leachate volumes and the amount of leached NH4+, K and Cd while AMF significantly increased the amounts of leached NO3−. Conclusions: Overall we found that AMF-colonized white clover plants reduced NH4+, K and Cd loss from soils but increased the risk of NO3− loss under high intensity leaching conditions.