Crop Nutrition Management and Soil Health in Cocoa Plantation Systems in Edo State

This study examines crop nutrition management practices and their relationship to soil health outcomes in cocoa plantation systems in Edo State, South South Nigeria. Cocoa is a major export crop in Edo State, and maintaining soil fertility in ageing plantation systems is critical for sustaining productivity. Current nutrition management practices range from mineral fertiliser application to organic shade tree management, with varying implications for soil health and long-term plantation viability. This study uses a mixed-method approach, combining soil and leaf tissue sampling from 30 cocoa farms in Ovia North-East, Orhionmwon, and Akoko-Edo local government areas with a structured survey of management practices among 80 cocoa farmers. Soil organic matter, pH, exchangeable cations, and micronutrients are analysed alongside leaf tissue nitrogen, potassium, and magnesium. Cocoa pod yield data are correlated with nutrition status and management practice indicators. Regression analysis identifies management determinants of soil health. Findings reveal that farms combining Gliricidia shade trees with periodic mineral fertiliser application show the highest soil organic matter and leaf nutrient concentrations, producing 42 percent higher pod yields than mineral fertiliser-only farms. Farms without shade management show the most severe soil acidification. Magnesium deficiency is identified as an underdiagnosed constraint in 38 percent of farms. The study concludes that integrated shade management is an essential component of sustainable cocoa nutrition management in Edo State. It recommends Gliricidia integration in cocoa rehabilitation programmes.

Keywords: crop nutrition, cocoa plantation, soil health, Edo State, shade management.