Evaluation of atmospheric CO2 sequestration by alkaline soils through simultaneous enhanced carbonation and biomass production

Maryol, e; Lin, C

Abstract

A series of microcosm experiments were conducted. The objectives were to evaluate the effects of Ca/Mg-bearing
materials on CO2 sequestration in highly alkaline sodic soils (Sodosol) through carbonation and biomass production. Application of gypsum resulted in an increase in inorganic carbon and a decrease in organic carbon. The
addition of talc did not significantly enhance carbonate formation. Soluble CaCl2 and MgCl2 did not have signifi-
cantly better effects on soil carbonation, as compared to gypsum. The one-year growth experiment using five
widely cultivated pasture grasses revealed that accumulation of carbonates following gypsum application
could be inhibited by plant growth; the organic acids secreted from plant roots were likely to facilitate soil carbonate dissolution. In comparison with pedogenic carbonation, carbon sequestration by biomass production
was much more evident. However, the biomass carbon gain varied markedly among the five species with
Digitaria eriantha showing the highest biomass carbon gain. This further enhanced the accumulation of soil
organic carbon. At the end of the experiment, an estimated CO2 sequestering capacity of 93 t/ha was achieved. The research findings have implications for cost–benefit analysis of alkaline soil reclamation projects.

• Journal Article Type: Article
• Acceptance Date: Oct 19, 2014
• Online Publication Date: Nov 8, 2014
• Publication Date: Mar 1, 2015
• Deposit Date: Mar 16, 2015
• Journal: Geoderma
• Print ISSN: 0016-7061
• Publisher: Elsevier
• Peer Reviewed: Peer Reviewed
• Volume: 241
• Pages: 24-31
• DOI: https://doi.org/10.1016/j.geoderma.2014.10.015
• Publisher URL: http://dx.doi.org/10.1016/j.geoderma.2014.10.015
• Related Public URLs: http://www.journals.elsevier.com/geoderma/