Biotechnologie, Agronomie, Société et Environnement (Jan 2011)
Décomposition des broyats de coques de cacao dans les sols ferrallitiques de la zone d'Oumé, centre-ouest de la Côte d'Ivoire : effets sur les caractéristiques chimiques des sols
Abstract
Decomposition of cocoa hulls in ferrallitic soils from Oumé region, Mid West of Côte d'Ivoire: effects on soils chemical characteristics. The effects of cocoa hulls on clayey and sandy ferrallitic soils were monitored during their decomposition trough incubations to study the interest of their use in soil fertilization. Two quantities of hulls: 1.39 g and 2.78 g which corresponded to 5 g C.kg-1 (D5) and 10 g C.kg-1 (D10) respectively, were brought to 100 g of each soil and compared to the non-amended control soil (D0). The experimental design was in Fischer blocks with six treatments and three replications. Carbon (C) mineralization and soil chemical parameters were measured. Results showed that cocoa hulls significantly influenced C mineralization. It increased significantly with D5 and decreased with D10 as compared to the control. Soil cation exchange capacity (CEC) varied from 3.94 to 5.65 cmolc.kg-1 with D5 and 5.19 to 6.31 cmolc.kg-1 with D10 and the sum of exchangeable bases varied from 3.13 to 4.14 cmol.kg-1 with D5 and 6.52 to 7.27 cmol.kg-1 with D10. Soil texture influenced significantly C mineralization, CEC and the sum of exchangeable bases with higher values obtained with clayey soils than with sandy soils. The study showed that cocoa hulls can be used to improve soil chemical characteristics, thereby soil fertilization in the Oumé region. However, the quantity must be controlled since there exists a threshold beyond which C mineralization is inhibited. Further studies should be undertaken with the aim to determine this threshold.
