Harnessing microbes: a new approach to carbon sequestration in cocoa agroforestry

Abstract

This study evaluated the carbon sequestration potential of fungal and bacterial strains in cocoa plantation soils in Ecuador’s coastal region using a randomized complete block design. Four microbial treatments were tested: Trichoderma longibrachiatum (T1), Trichoderma reesei (T2), Bacillus subtilis (T3) and Bacillus licheniformis (T4). All microorganisms showed high viability, with bacterial and fungal colony-forming units exceeding 10⁸ and 10⁶ CFU/ml, respectively. T. longibrachiatum and T. reesei significantly outperformed the bacterial treatments in carbon sequestration (p<0.0001). T. reesei achieved a 29% increase in carbon sequestration after the first application, while B. subtilis showed an 11.25% increase after four applications, though with decreasing efficacy. B. licheniformis maintained NH₄⁺ at 19.00 ppm, Zn at 5.60 ppm, Mn at 5.20 ppm, and B at 0.61 ppm, while increasing P to 66.00 ppm, K to 1.89 Meq/100ml, Ca to 19.00 Meq/100ml, Mg to 5.10 Meq/100ml, S to 50.00 ppm, Cu to 5.20 ppm, and Fe to 54.00 ppm. Future research should focus on optimizing microbial dosages and application methods to enhance carbon capture and cocoa productivity.