Abstract

The global demand for crop production has led to an increased in the use of inorganic fertilizer. However, single and long-term use of inorganic fertilizer negatively affects the environment and soil structure. Alternatively, organic materials can be composted and used as fertilizer. Although organic fertilizers have low nutrient concentration and solubility, they slowly release nutrients, making them available for a more extended period. Moreover, the waste by-products such as biomass and manure from plantations and livestock farms are readily available in abundance. Therefore, this study was conducted to determine the effects of four organic fertilizers (chicken manure, cow manure, empty fruit bunch, and cocoa pod husk) and inorganic fertilizer as a control on the soil chemical properties and production of cocoa. We found that organic fertilizers, at their optimal application rate, yielded similar cocoa dried beans production with inorganic fertilizer. Furthermore, we found that there was no difference in the soil chemical properties between the treatments. Hence, this study has demonstrated that organic fertilizers could improve soil chemical properties and eventually increase cocoa production.

Key words: Cocoa, Organic fertilizers, Soil chemical properties