An arbuscular mycorrhizal fungus increased the macroaggregate proportion and reduced cadmium leaching from polluted soil

A pot experiment was conducted using maize (Zea mays L.) as the host plant grown in cadmium (Cd)-polluted soil and inoculated with an arbuscular mycorrhizal fungus (AMF), Funneliformis mosseae. The effects of AMF on Cd uptake by maize, water-stable aggregate proportion, Cd concentration in pore water and Cd leaching were investigated. The results showed that AMF significantly promoted maize biomass and Cd uptake in shoots, and increased the content of total and easily extractable glomalin-related soil protein in the 0–40 cm soil layers. Furthermore, AMF increased the proportion of >0.85 mm water-stable aggregates (macroaggregates) by 47–88% and decreased the available Cd content in soil by 20–24%. During the first and second leaching events, AMF significantly decreased the Cd concentration in pore water, and reduced the Cd leaching loss from soil by 12.6% and 19.9%, respectively. Correlation analysis indicated that the macroaggregate proportion was positively correlated with the total and easily extractable glomalin-related soil protein content and negatively correlated with the Cd concentration in pore water, and the Cd concentration in pore water was positively correlated with the Cd leaching loss from soil. Therefore, the AMF-reduced Cd leaching was closely related to the increased macroaggregate proportion in soil.Novelty statement AMF significantly increased the GRSP content and the macroaggregate proportion in soil, which contributed to reducing the Cd concentration in pore water and its leaching loss from soil.