Prediction of selenium uptake by pak choi in several agricultural soils based on diffusive gradients in thin-films technique and single extraction. (January 2020)

• Record Type: Journal Article
• Authors: Peng, Qin; Wang, Dan; Wang, Mengke; Zhou, Fei; Yang, Wenxiao; Liu, Yongxian; Liang, Dongli
• Is Part Of: Environmental pollution. Volume 256(2020)
• Publication Date: 2020-01
• Subjects: Soil properties -- Bioavailability -- DGT method -- Single extraction -- Selenite -- Selenate; Pollution -- Periodicals; Pollution -- Environmental aspects -- Periodicals; Environmental Pollution -- Periodicals; Pollution -- Périodiques; Pollution -- Aspect de l'environnement -- Périodiques; Pollution -- Effets physiologiques -- Périodiques; Pollution; Pollution -- Environmental aspects; Periodicals; Electronic journals; 363.73
• DOI: 10.1016/j.envpol.2019.113414
• Languages: English
• ISSNs: 0269-7491

Abstract

Abstract: The accurate assessment of soil selenium (Se) bioavailability is crucial for Se biofortification in Se-deficient areas and risk assessment in selenosis areas. However, a universally accepted approach to evaluate Se bioavailability in soil is currently lacking. This research investigated Se bioavailability in six soils treated with selenite (Se(IV)) or selenate (Se(VI)) by comparing diffusive gradients in thin-films (DGT) technique and chemical extraction methods through pot experiments. A bioindicator method was used to evaluate Se concentrations in pak choi and compare the results with the Se concentration measured by other methods. Results showed that chemical extraction methods presented different extraction efficiencies for available Se over a range of soil types, and the same extraction method had various extraction efficiencies for different Se species in the same soil. DGT measured Se concentrations ( C DGT −Se) for Se(VI) treatment were 2.3–34.1 times of those for Se(IV) treatment. KH2 PO4 –K2 HPO4 and AB-DTPA extractable Se could predict the bioavailability of soil Se, but they were disturbed by soil properties. HAc extraction was unsuitable for evaluating Se bioavailability in different Se(IV)-treated soils. By contrast, DGT technique was preferable for predicting plant uptake of Se(IV) over chemical extraction methods. Although DGT technique was independent of soil properties, KH2 PO4 –K2 HPO4 extraction provided the best fitting regression equation for Se(VI) when it was dependent on soil organic matter. Thus, KH2 PO4 –K2 HPO4 extraction may be preferred to assess Se(VI) bioavailability in different soil types on a large scale. Graphical abstract: Image 1 Highlights: Selenate and selenite bioavailability was compared in several agricultural soils. DGT technique was firstly used to assess Se bioavailability in a range of soils. Soil properties were considered in assessment of Se bioavailability. DGT may be more preferable to assess Se(IV) bioavailability than chemical extraction. Abstract : DGT technique is a superior predictive method for Se(IV) bioavailability in different soil types on a large scale, but KH2 PO4 –K2 HPO4 extraction may be more suitable for Se(VI).