Prediction and pathway models for assessing soil properties influencing soil selenium enrichment and bioavailability in Aksu Prefecture, northwest China

Hui Zhai; Yunshu Zhang; Wanli Xu; Wenyu Hou; Guangmu Tang; Chunhui Ge; Huawei Shao; Haotian Gong; Yujian Wang; Yumeng Liu; Lei Pan; Li Ling

doi:10.1016/j.scitotenv.2024.177524

Prediction and pathway models for assessing soil properties influencing soil selenium enrichment and bioavailability in Aksu Prefecture, northwest China

Sci Total Environ. 2024 Nov 21:957:177524. doi: 10.1016/j.scitotenv.2024.177524. Online ahead of print.

Authors

Hui Zhai¹, Yunshu Zhang², Wanli Xu³, Wenyu Hou¹, Guangmu Tang³, Chunhui Ge³, Huawei Shao³, Haotian Gong¹, Yujian Wang¹, Yumeng Liu¹, Lei Pan¹, Li Ling¹

Affiliations

¹ College of Ecology and Environment, Xinjiang University, Urumqi 830046, China; Key Laboratory of Oasis Ecology of Education Ministry, Xinjiang University, Urumqi 830046, China.
² Institute of Soil and Fertilizer, Agricultural Water Saving, Xinjiang Academy of Agricultural Sciences, Urumqi 830092, China. Electronic address: zhangyunshu@xaas.ac.cn.
³ Institute of Soil and Fertilizer, Agricultural Water Saving, Xinjiang Academy of Agricultural Sciences, Urumqi 830092, China.

PMID: 39549756
DOI: 10.1016/j.scitotenv.2024.177524

Abstract

Selenium (Se) in soil is the primary source of human Se intake, and its content and bioavailability are influenced by soil physicochemical properties. However, the influence of soil physicochemical properties on Se enrichment and bioavailability in soil remains uncertain. Therefore, this study investigated 536 soil samples and their corresponding wheat grain samples collected from the oasis zone of Aksu Prefecture, located in northwest China. The Se content, spatial distribution, and bioaccumulation factor (BCF) in soil and wheat grains as well as soil Se fractions were examined, and the effects of soil physicochemical properties on Se enrichment and bioavailability were assessed. The results indicated that the mean Se content of soil (0.32 mg/kg) surpassed the national Se background level for Chinese soil by a factor of 1.10. The average Se content (0.13 mg/kg) in wheat grains met the national standard for Se-rich cereal products. The prediction model established using multiple linear regression showed that soil calcium carbonate (CaCO₃), organic matter (OM), cation exchange capacity (CEC), and electrical conductivity (EC) were the main physicochemical factors influencing Se enrichment in soil, accounting for 29 % of the variation. The main physicochemical factors affecting Se bioavailability were CaCO₃, OM, and iron, and the main Se fractions were the exchangeable and humic acid-bound Se fractions, which together explain 12 % of the variance. Additionally, a structural equation model was employed to analyze the pathways and interactions of soil factors on soil Se enrichment and bioavailability. The results indicated that soil CaCO₃ and OM were the most critical factors affecting Se enrichment and bioavailability in soil. These findings can provide technical guidance for the cultivation and layout of Se-rich wheat in local and other similar regions around the world.

Keywords: Bioaccumulation factor; Enrichment; Se fractions; Selenium (Se); Soil properties.