Cocoa in monoculture and dynamic agroforestry

Summary

The growing demand for cocoa beans and products worldwide has been met by expanding the area under cocoa production while productivity per hectare has stagnated at a low level of around 450 kg/ha per year in the last decade. Throughout the tropics cocoa has increasingly been cultivated in full-sun monocultures in order to maximize short-term productivity and profitability, which has been associated with soil erosion and degradation, biodiversity loss, as well as increased susceptibility to climate change impacts and pests and diseases. Dynamic agroforestry systems are an alternative production method which has long been practiced in Latin American countries such as Bolivia. Through mimicking natural forests, these systems offer multiple benefits such as soil fertility enhancement, reduction in pest and disease pressure, erosion control, and revenue diversification. In Côte d’Ivoire, where most cocoa is still produced in monocultures, dynamic agroforestry systems were recently introduced on a small scale.
Here we use different research projects conducted in Bolivia and Côte d’Ivoire as case studies to review productivity, soil fertility as well as pests and diseases in dynamic agroforestry systems and monocultures, and outline factors influencing the adoption of dynamic agroforestry systems from the farmers’ perspective. We found productivity under agroforestry systems to be either similar or higher compared to monocultures. We recorded 161 % higher total system yields in an on-station field trial and an on-farm study in Bolivia, and in an on-farm study in Côte d’Ivoire. Cocoa yields were 12–46 % higher in agroforestry systems compared to monocultures. In addition, cocoa in dynamic agroforestry systems exhibited significantly less incidences of witches’ broom, Moniliophthora perniciosa, compared to monocultures in Bolivia.
Farmers in Bolivia and Côte d’Ivoire observed more soil-related problems and incidences of pests and diseases in monocultures than in agroforestry systems, and they showed high interest to learn dynamic agroforestry management practices. However, adoption was strongly limited to project areas where dynamic agroforestry plots had been installed with farmers’ participation. This highlights the importance of local organizations such as Ecotop, Ecosaf, El Ceibo and Biopartenaire Ltd., who implement such interventions on the ground. However, we found that there is space for improvement in the way organizations interact with farmers, especially in Côte d’Ivoire. Interactive knowledge sharing methods such as farmer field schools may help to stimulate farmers’ protagonism and give scientists and external consultants the role of facilitators who integrate different forms of knowledge and make them visible to different stakeholders. Such a social learning process requires transdisciplinary research for the development of decision support tools which facilitate the determination of both optimal planting densities and shade levels, as well as adequate combinations of trees and accompanying species in order to achieve effective regulation of pests and diseases while ensuring favourable growing conditions.