Multivariate model for predicting crop fluorine content based on soil physicochemical properties and fluorine...

Fluoride (F), an essential trace element with dual health implications, poses significant ecological risks when its biogeochemical cycle is disrupted in soil-crop systems. This study addresses the limitations of total soil F content in assessing crop F bioavailability through a systematic investigation of 30 paired agricultural soil-wheat samples from Zhouzhi County, Guanzhong Plain. Sequential extraction revealed residual F as the dominant speciation (79.5-99.04% of total F), significantly restricting its environmental mobility. While surface soils exhibited elevated total F (753.3 mg kg⁻¹ mean), wheat grains maintained safe F levels (1.2 mg kg⁻¹ mean). A robust multivariate model (R² = 0.72) integrating water-soluble F, CaO, Mn, Al_ox-Fe_ox complexes, P, and pH effectively predicted wheat F accumulation, with water-soluble F contributing the biggest to total variance. These findings could provide scientific support for green agricultural practices in F-affected regions.