Investing in intercropping
Better income, increased diversity and less environmental degradation are just some of the advantages that result from establishing a cocoa agroforest. Intercropping cocoa with food crops is common practice when cocoa seedlings are being established and successful interplanting of coconut with mature cocoa is well documented. But cocoa plantations can be greatly enriched by planting additional tree crops, which can provide fruit, timber and fuel. Cocoa is well adapted to inclusion in multi-product and multi-strata agroforests in West Africa and Central America and, by diversifying production, smallholder farmers can safeguard their income should cocoa prices fall.
Cocoa agroforests are common in southern Cameroon where they are known to remain productive for up to fifty years. But the system could be adopted more widely in other regions of West Africa where food crop production based on slash-and-burn agriculture still occurs. Yet understandably, smallholder farmers that traditionally practise shifting cultivation have little concern for the environment; their main concern is to feed their families. So they can only be expected to adopt agroforestry practices if the benefits of increased income can be clearly demonstrated.
The establishment of cocoa agroforests also requires the partial clearing and burning of forest but the clearing is done manually which, together with the no-tillage method used when planting, reduces disturbance to the soil. Cocoa, when mature, also produces considerable leaf litter and provides good cover so minimal damage occurs to the fragile soil in these systems. When land is cleared, indigenous fruit, medicinal and timber trees are deliberately retained. Cultivation of these tree crops amongst the cocoa ensures a productive, diverse system resembling the full canopy of a rain forest, provides shade for the cocoa plant and, most importantly for the farmer, provides valuable, income-generating products. In addition, food crops, planted as nurse crops within and around cocoa plots, can serve to shade and protect young cocoa seedlings.
Intercropping of food crops, such as maize, plantain and cassava, takes place for three to five years whilst the cocoa trees mature. The system is then further enriched with the planting of additional multi-purpose fruit trees like mango (Mangifera indica), bush mango (Irvingia gabonensis), African plum (Dacryodes edulis), avocado (Persea americanum), guava (Psidium guajava) and citrus species (C. sinensis and C. reticula). Medicinal trees such as Alstoonia boonia, used for suppressing malarial fevers, are also planted. Timber from many of these trees is used for local construction. Most of the indigenous and exotic tree species grown in the agroforests are genetically unimproved. So researchers at ICRAF (International Centre for Research in Agroforestry) and IRAD (Institute of Agricultural Research for Development) in Cameroon are keen to help farmers by enhancing the productivity of some of these varieties and identifying pest and disease resistant strains. However, some species are difficult to propagate and research is needed to identify selection and cultivation techniques to make this sustainable cocoa system more attractive to farmers. (see Focus On . . . Agroforestry 98-3).
In Ghana and Côte d'Ivoire, livestock have also been successfully integrated into tree crop systems on experimental research stations. With care taken to avoid degradation of the soil, animals, such as small ruminants, can provide additional benefits to the cocoa agroforests. The vegetation under cocoa may be harvested (cut and carry) for feeding to small ruminants kept on the homestead.
Farmers are able to establish cocoa agroforests with little input required from research institutes. However, further research can help farmers optimize the production of these systems so that they are ensured of a stable income from the diverse products available within the system, whatever the price of cocoa.
In Costa Rica and Panama, leguminous or timber trees have been introduced into existing cocoa plantations as a cheap alternative to replace undesirable existing shade canopies. The use of leguminous species (Gliricidia sepium, Erythrina poeppigiana or Inga edulia), especially when pruned regularly, has been shown to accelerate nutrient cycling. Timber species (Cordia alliodora, Terminalia ivorensis or Tabebuia rosea) can also be combined with leguminous species to ensure quick cover, reduce weed infestation, reduce management costs and increase financial performance. Environmental degradation is also minimized by managing ground cover through selection of the tree species planted for shade, using companion crops, and selecting specific plantation densities (not more than 100-150 trees/ha is recommended) and planting arrangements.
As in West Africa, these diversified systems have been shown to be more productive than cocoa monocrops and financially more viable. A short rotation to produce commercial timber trees has also facilitated the incorporation of small-medium farms in reforestation programmes. Financial performance of most systems has been satisfactory especially when labour is cheap. Plantain, timber crops and the use of short-term crops as temporary shade in new cocoa plantations has been particularly successful. Diversification of species to provide additional income-generating products also reduces the need to produce high, cocoa yields which can only be obtained through intensive use of agrochemicals. Through the further development of these CATIE-GTZ agroforestry systems in Costa Rica and Panama, it is hoped that more farmers will be motivated to adopt these diverse cocoa plantations.
