BCF Better Reflects the Bioavailability of Selenium in the Soil of the Northeastern Guanzhong Plain Compared to MF

Abstract

A large area of selenium-rich soil has been identified in the Guanzhong Plain; however, the bioavailability of selenium remains poorly understood, which poses significant challenges to the development and utilization of these resources. This study investigates selenium bioavailability by focusing on surface soils, wheat grains, and rhizosphere soils in the northeastern Guanzhong Plain. The results reveal that the average selenium content in surface soil exceeds the background levels for both the Guanzhong Plain and China. Humic acid-bound selenium and strongly organically bound selenium are the predominant forms in rhizosphere soil. The bioconcentration factor (BCF) better reflects the bioavailability of selenium in the soil of the northeastern Guanzhong Plain compared to the mobility factor (MF). Moreover, selenium bioavailability in the study area is notably higher than in surrounding regions. These findings offer valuable insights into the sustainable development and efficient utilization of selenium-rich land resources in this region.