Effect of Municipal Solid Waste Compost on Soil Chemical Properties and Growth Performance of Cocoa (Theobroma cacao L.) Seedlings at the Nursery in Ghana

Abstract

Aims: Availability of nutrients-rich topsoil for nursing cocoa seedlings is becoming limited and poor growth of cocoa seedlings in the nurseries has been ascribed to the use of unsuitable potting media. Experiments were conducted to investigate the suitability of compost in improving soil chemical properties and boost the growth of cocoa seedlings at the nursery. Study Design:  The experiment was laid out in a Completely Randomized Design (CRD) with four replications. Place and Duration of Study: The experiment was carried out at the main nursery of Cocoa Research Institute of Ghana, New Tafo-Akim, between September, 2014 and June 2015. Methodology: Polybags were filled with soil obtained from an old cocoa plot (K6O2) at Cocoa Research Institute of Ghana. The soil has been classified as Rhodic-Lixic Ferrasol. Three soil: compost mixtures treatments, that is, 90:10, 80:20 and 70:30% w/w were tested. A Standard foliar fertilizer and unamended soil were included as treated and untreated controls. Seedlings were raised from mixed hybrid cocoa and assessed at bi-monthly intervals for six months for growth. Pre and post treatments soil analyses were carried out using standard laboratory procedures. Results: Initial soil analyses showed that OC (1.18%), Ca (5.60 cmol kg-1), P (14.23 mg kg-1) and pH (5.63) were below the critical values required for good cocoa growth. The 70:30 soil: compost treatment produced significantly (P = .05) tallest plant (41.9 cm) with the unamended control the shortest (30.7 cm) at the end of the study. Residual pH (6.98), OC (2.30%), P (14.23 mg kg-1) and Ca (13.02 cmol kg-1) were significantly (P = .05) higher under the same treatment compared to the unamended control; pH (5.36), OC (1.04%), P (11.65 mg kg-1) and Ca (5.60 cmol kg-1). Conclusion: Less fertile soils could be improved with the addition of Municipal Solid Waste (MSW) compost for raising good quality cocoa seedlings at the nursery in Ghana.