Geochemical characteristics of soils in Fezzan, Sahara desert : implications for environment and agriculture

Maryol, E; Lin, C

Abstract

An investigation was conducted to geochemically characterize the soils in Fezzan of the Sahara desert in order to
assess (a) the role of the soils as a carbon store, (b) the potential risk of the fine-grained soil fraction as a dust
source, and (c) the potential soil constraints for the development of irrigation agriculture. The results show
that, on average, there was about 0.7% of carbon stored in the topsoil with approximately 1/3 being inorganic
carbon and 2/3 being organic carbon. The fine-grained soil fraction contained 2.13% of Fe and 252 mg/kg of phosphorus,
indicating that the Fezzan area could be an important source of ocean iron and phosphorus. Manganese
and strontium were identified as the major chemical pollutants potentially present in the dusts. The soils were
generally alkaline and saline. Sodium dominated the soluble basic cations with a mean sodium adsorption
ratio N16. Calcium dominated the exchangeable basic cations with a mean exchangeable sodium percentage of
6.52, suggesting thatmost of the topsoils were not sodic. However, there was a tendency that sodicity increased
with depth for some soils. Different strategies are proposed for reclaiming the soils using the groundwater from
the Great Man-made River Project.

Citation

Maryol, E., & Lin, C. (2015). Geochemical characteristics of soils in Fezzan, Sahara desert : implications for environment and agriculture. Journal of Geochemical Exploration, 158, 122-131. https://doi.org/10.1016/j.gexplo.2015.07.009

• Journal Article Type: Article
• Acceptance Date: Jul 14, 2015
• Online Publication Date: Jul 26, 2015
• Publication Date: Jul 26, 2015
• Deposit Date: Mar 22, 2016
• Journal: Journal of Geochemical Exploration
• Print ISSN: 0375-6742
• Electronic ISSN: 1879-1689
• Publisher: Elsevier
• Volume: 158
• Pages: 122-131
• DOI: https://doi.org/10.1016/j.gexplo.2015.07.009
• Publisher URL: http://dx.doi.org/10.1016/j.gexplo.2015.07.009
• Related Public URLs: http://www.journals.elsevier.com/journal-of-geochemical-exploration/