Effect of soil properties and contact time on selenium transfer to wheat

To assess the fate of residually added selenium (Se) fertilizer in soil over time, many studies have used chemical extraction methods to quantify “available” Se. Soil Se was fractionated by sequential extraction procedures into soluble Se by CaCl₂ extraction, adsorbed Se by KH₂PO₄ extraction and organically bound Se byTMAH extraction, and analysed by ICPOES after hydride generation. Transfer factors varied significantly among soils, from 28.9 to 238 within the first month, with the highest transfer factor observed in alkaline soils, probably due to the predominance of selenate ions. The bioavailability of Se was influenced by soil properties such as pH and soil texture, as well as incubation time. By investigating the effect of soil parameters and contact time on the availability of Se added to soil, the chapter focuses on the fate of Se fertilizer used in crop biofortification and has possible implications for environmental safety.