Contrasting impacts of drying-rewetting cycles on the dissipation of di-(2-ethylhexyl) phthalate in two typical agricultural soils

Di-(2-ethylhexyl) phthalate (DEHP) pollution has become a growing problem in farmlands of China. Drying-rewetting (DW) cycle is one of frequent environmental changes that agricultural production is confronted with, and also a convenient and practical agronomic regulation measure. In this study, in order to explore the ef-fects of DW cycles on the dissipation of DEHP and their driving mechanisms in different types of soils, we per -formed a 45-day microcosm culture experiment with two typical agricultural soils, Lou soil (LS) and Red soil (RS). High-throughput sequencing was applied to study the response of soil microbial communities in the pro-cess of DEHP dissipation under DW cycles. The results showed that the DW cycles considerably inhibited the dis-sipation of DEHP in LS while promoted that in RS. The DW cycles obviously decreased the diversity, the relative abundance of significantly differential bacteria, and the total abundance of potential degrading bacterial groups in LS, whereas have little effect on bacterial community in RS, except at the initial cultivation stage when the cor-responding parameters were promoted. The inhibition of the DW cycles on DEHP dissipation in LS was mainly derived from microbial degradation, but the interplay between microbial functions and soil attributes contrib-uted to the promotion of DEHP dissipation in RS under the DW cycles. This comprehensive understanding of the contrasting impacts and underlying driving mechanisms may provide crucial implications for the prevention and control of DEHP pollution in regional soils (c) 2021 Elsevier B.V. All rights reserved.