Responses of microbial communities to the addition of different types of microplastics in agricultural soils

A 90-day soil incubation study was performed to investigate impacts of four types (PE, PP, PVC and PET) of microplastics (MPs) on the physicochemical properties, nutrient contents, enzyme activities, and microbial community structure and diversity of agricultural soils. Effects of the four microplastic types and addition ratios on the microbiology of the agricultural soils were significant. With the addition of MPs, there was a positive correlation between physicochemical properties, nutrients (AN, AP, AK) and enzyme activities (CAT, Urease, ACP, SUC), which were all decreased to some extent. Overall PE and PVC surfaces were the roughest and had the greatest impact on soil physicochemical properties, nutrients and enzyme activities. The changes in soil microbial α-diversity were not significant (P > 0.05), but, PP and PVC led to an increase in community diversity and abundance. Clearly, the four types of the MPs reduced the physicochemical properties, nutrient content, enzyme activity and microbial community, and thus significantly affected the microbiology of the farmland soils.