SOIL FERTILITY STATUS UNDER ORGANIC AND CONVENTIONAL COCOA CROPPING SYSTEMS AT ATWIMA MPONUA DISTRICT IN GHANA

Abstract

Globally consumers are becoming increasingly concerned about the safety of the food they consume and how sustainable the production systems are. Organic agriculture has been suggested to have relatively minimal negative environmental effects and are more sustainable. Research is needed on how to manage soil fertility of organic cocoa production systems in a sustainable way in the midst of constraints in organic production protocols and current knowledge levels. Physical, chemical and biological characteristics of soils cultivated under conventional and organic cocoa production systems for eight years in the Atwima Mponua district were studied. Soil samples were taken from 0-30 and 30-60 cm depth and analyzed. Results showed that, there was significant difference between the two cropping systems (organic and conventional) in relation to soil chemical and biological properties, as well as litter fall and cocoa bean yield. The silt and clay content of the 0-30 cm soil depth of organic cropping system was higher than that of the conventional cropping system by 22 and 14% respectively. Greater accumulation of organic matter under organic cocoa production over eight-year period increased cation exchange capacity and soil microbial respiration by 36% and 21%, respectively. The soil pH, P, K, Ca, and Mg of the 0-30 cm depth of organic was higher than that of the conventional cropping system by 7.9%, 12.8%, 12.5%, 54.8%, and 56.7% respectively. The improved soil physical, chemical and biological characteristics under organic cocoa production translated into 43% increase in cocoa bean yield compared to conventional production system. These results show that organic cocoa production is a viable production option for improved and sustainable cocoa production.