Distribution characteristics of selenium and influencing factors in the plant–soil system of an arid oasis

Abstract

A total of 323 topsoil samples, 63 profile soil samples, and 55 plant root samples were collected from an oasis area on the eastern margin of the Tarim Basin in China and the selenium content and other physical and chemical indicators were analyzed. The results showed that the average selenium content in the surface soil was 0.15 mg/kg, which was lower than the national background value, and only about 4% of the surveyed land area was classified as rich in selenium. The vertical distribution of selenium was characterized by surface accumulation. The organic carbon and clay content were positively correlated and the pH levels negatively correlated with the selenium content. Soil type had little effect on selenium content, though the selenium levels in Anthrosols and Gleysols were relatively high. The selenium content for cultivated land and garden soil was higher than for other land use types. The enrichment of selenium in plant roots was highest for Apocynum venetum L., followed by Pulicaria dysenterica (L.). Bernh., Populus euphratica Olive, Tamarix chinensis Lour., Phragmites australis (Cav.) Trin. ex Steud, and Pyrus bretschneideri Rehder. Correlation analysis revealed that the enrichment of selenium in the soil was mainly controlled by supergenesis in conjunction with long-distance migration and deposition. Overall, this study provides useful information for the rational development and utilization of regional land resources.

Keywords:

• Chemical property
• land use
• physical property
• soil selenium
• soil type
• Tarim Basin

Acknowledgement

We thank the anonymous reviewers for their constructive comments and suggestions.

Authors’ contribution

Conceptualization, J.L. and S.T.; methodology, J.L. and Y.Z.; software, L.Z.; validation, L.M., J.L., and X.L.; formal analysis, J.L.and L.H.; investigation, L.L.; resources, J.L.; data curation, L.Z.; writing—original draft preparation, J.L.; writing—review and editing, S.T.; visualization, L.Z.; supervision, J.L.; project administration, J.L.; funding acquisition, J.L. All authors have read and agreed to the published version of the manuscript.

Disclosure statement

The authors declare no conflict of interest.

Data availability statement

All data are contained within this article and Supplementary Materials.

Additional information

Funding

Supported by Open Foundation of the Key Laboratory of Coupling Process and Effect of Natural Resources Elements (No.2024KFKT019); Supported by the Geological Survey Projects of the China Geological Survey (DD20242035, DD20191026).