Nutrient Release Pattern of Cocoa Pod Husk Based Composts in an Incubation Study

In order to apply compost to fulfill the nutrient requirements of a crop, knowledge of the amount of nutrients mineralized following application is needed. The objective of this study was to compare the effect of different cocoa pod husk based composts on soil nutrient status as well as the pH. The experimental design was 4 x 2 x 5 factorial laid in a completely randomized design replicated three times. The factors were four compost types; Cocoa Pod Husk + Poultry Manure + Neem leaves (CPH + PM + NL), Cocoa Pod Husk + Poultry manure (CPH + PM), Cocoa Pod Husk + Neem leaves (CPH + NL) and No compost (Control), two soil types; Ibadan (Alfisol) and Ikenne (Ultisol) and five incubation periods; 2, 4, 6, 8 and 10 weeks. Each compost was applied separately at the rate of 10 tons ha-1. Routine analysis of the soil before incubation indicated that the two soil types had low nutrient status. The composts significantly (p<0.05) influenced the soil nutrient status after incubation. Correlation of nutrient release with time by composts showed that there was no correlation between the time of incubation and nutrient release from all the composts except in the case of CPH + PM that had significant relationship with the release of N. The result showed that the N release from CPH+PM decreases with time of incubation. The pH of the soils treated with different composts was significantly increased compared with control.