Divergent response of heavy metal bioavailability in soil rhizosphere to agricultural land use change from paddy fields to various drylands

-C content. Moreover, the dissolved organic carbon (DOC) content increased, which positively affected the Eh and, in turn, increased the bioavailability of heavy metals. This research is of great significance for understanding the impact of land use change on the heavy metal migration and activity in the rhizosphere microenvironment of soil.