Analyse de la diversité des systèmes de pratiques en cacaoculture. Cas du Centre Cameroun

Analysis of the diversity of cocoa cropping systems. Case of the Central Cameroon. Little is known about the cultural practices adopted by cocoa farmers in Central Cameroon. In order to bridge that knowledge gap, 1,428 farms were surveyed in four divisions of Centre province, which differed through the prevailing type of cocoa cultivation. Farmer typologies were established, based on their cultural practices for cocoa growing. Three scales of investigation were considered: province, division and village. This study confirmed the diversity of cocoa growing systems existing in Central Cameroon. A multidimensional exploratory analysis revealed that the links between the variables considered varied substantially from one division to another, though the degree of intensification in inputs and labour were the main determinants of cocoa yields. Four to five categories of farmers, which differed from each other depending on the variables studied, were found for each scale of investigation. In methodological terms, the classification method adopted to establish the typologies confirmed its efficiency. It showed that data analysis on a village scale relativized the results observed on a division scale, by making it possible to identify the cocoa growing system dominating a given village. This approach therefore enabled a better appreciation of similarities between the study zones, similarities which administrative or geographical zoning tended to hide. It suggested that it is necessary to assist farmers taking into account the diversity of situations

Improving field establishment of cacao (Theobroma cacao) through mulching, irrigation and shading

Establishment of young cacao trees in West Africa can be severely impeded by the on-set of the dry season. To address this issue, a field experiment was conducted in Ghana to examine whether different mulch treatments and irrigation applied during the dry season combined with over-head shade could improve survival, early growth and yield of cacao. The mulch treatments used were polyethylene film and coffee husks placed around the young plants. Irrigation was used as a positive control and no mulching or irrigation was a negative control. Three shade regimes were provided through different arrangements of Gliricidia sepium and plantains. Four different cacao clones were used in the study in a replicated split-plot design. Early growth of cacao was stimulated under the irrigation and plastic mulch treatments. Higher rates of photosynthesis during the dry season appeared to underlie these increases. Significantly higher early yields were also observed under the irrigation and coffee mulch treatments compared to the control. Plant survival varied significantly between treatments; irrigation was associated with the highest plant survival (94%), followed by the plastic mulch treatment (91%), coffee husk (82%) and the control (70%). There was also an increase in survival when more intense shading was used. Under zero mulch conditions, differences in survival were observed between clones. The clones P 30 [POS] and SCA 6 were more sensitive to drought (in terms of survival) than PA 150 and T 79/501. It is concluded that relatively simple mulching techniques or controlled irrigation in conjunction with appropriate shade management can significantly improve early establishment and cropping of cacao

LCA applied to perennial cropping systems: a review focused on the farm stage

International audienc

Agroforesterie et services écosystémiques en zone tropicale

Respectueux de l’environnement et garantissant une sécurité alimentaire soutenue par la diversification des productions et des revenus qu’ils procurent, les systèmes agroforestiers apparaissent comme un modèle prometteur d’agriculture durable dans les pays du Sud les plus vulnérables aux changements globaux. Cependant, ces systèmes agroforestiers ne peuvent être optimisés qu’à condition de mieux comprendre et de mieux maîtriser les facteurs de leurs productions. L’ouvrage présente un ensemble de connaissances récentes sur les mécanismes biophysiques et socio-économiques qui sous-tendent le fonctionnement et la dynamique des systèmes agroforestiers. Il concerne, d’une part les systèmes agroforestiers à base de cultures pérennes, telles que cacaoyers et caféiers, de régions tropicales humides en Amérique du Sud, en Afrique de l’Est et du Centre, d’autre part les parcs arborés et arbustifs à base de cultures vivrières, principalement de céréales, de la région semi-aride subsaharienne d’Afrique de l’Ouest. Il synthétise les dernières avancées acquises grâce à plusieurs projets associant le Cirad, l’IRD et leurs partenaires du Sud qui ont été conduits entre 2012 et 2016 dans ces régions. L’ensemble de ces projets s’articulent autour des dynamiques des systèmes agroforestiers et des compromis entre les services de production et les autres services socio-écosystémiques que ces systèmes fournissent

Amélioration du système traditionnel de caféiculture au Cameroun par l'introduction de trois innovations techniques

Improvement of traditional coffee farming system in Cameroon by introducing three technical innovations. With the aim to improve the traditional coffee (Coffea canephora Pierre, var. Robusta) growing practices in the Center of Cameroon, trials were conducted with coffee farmers. Three innovations were tested: use of selected coffee materials, double-line hedge planting, and their association with food-crops in the space between coffee lines. Three years after planting, the superiority of the newly tested system is obvious. The selected coffee clones were 2.4 more productive than ordinary seedlings taken in old plantations. Similarly, with the double-line hedge system with food-crops in the space between coffee lines, the production of calories was increased by 2.8 and the production of proteins by 5.2 compared with the traditional system. From an economic point of view, the current crisis in the coffee production has reduced the interest of farmers for highly selected coffee material. However, it has strengthened their interest for the newly tested planting system with a wider space for food-crops. The profi t margin of the improved system is estimated to be 257,600 CFA instead of 100,150 CFA for the traditional system using foodcrop in between coffee trees. All crops taken together, the improved system gives a rise of 300 CFA per work day, compared to the traditional coffee farming syste

Diversification des exploitations agricoles à base de cacaoyer au Centre Cameroun : mythe ou réalité ?

Diversification of cocoa farms in the Central Cameroon: myth or reality? A survey was conducted among 1,171 farmers to assess the degree of diversification on cocoa-based farms in the Centre Province of Cameroon, which is the main cocoa producing zone in the country. Fifteen years after the onset of liberalization of the cocoa supply chain, the results showed that area under cocoa predominates in the cropping plan on a farming system scale. The same applied for the contribution made by cocoa income to overall farm functioning. However, a further study carried out on 74 cocoa plantations in that region showed that diversification was more perceptible on the cocoa based production systems. In fact, fruit tree species, which are very often found in cocoa plantations, partly explained the occurrence of substantial agrobiodiversity. A north – south gradient was found in which diversification of the cocoa growing system was significantly greater in the forest – savannah transition zone than in the forest zone. However, it turned out that the process of diversification by planting fruit tree species in cocoa plantations was not a new phenomenon, since it involved all cocoa plantings whatever their age. This research thus relativizes the extent of the diversification strategy adopted by cocoa producers in the Centre Province of Cameroon in response to changes in their socioeconomic environment and the instability of international markets

How agronomy can deal with agroforests?

International audienc

Afforestation of savannah using cocoa agroforestry: :impacts on ecosystem services and effects of associated tree species on soil fertility

International audiencePast studies showed a gradual expansion of forest over savannah in forest-savannah transition zones in Central Africa. While the natural encroachment of savannah by forest is more and more impeded by human activities, farmers in Cameroon have proven that afforestation of savannah is achievable using cocoa and specific technics to build up an associated tree canopy. Furthermore, mature cocoa agroforestry systems created on savannah (S-cAFS) or in forest (F-cAFS) exhibit comparable multi-strata structures. By combining measurements of cocoa yield, litterfall, soil quality, carbon storage and tree species diversity along an age gradient (1 to 70 years), we showed that those variables in S- and F-cAFS tended to comparable levels after several decades. Results also emphasized the ability of S-cAFS to increase most of the ecosystem services (including soil fertility and plant diversity) although the time needed to reach levels found in F-cAFS varied strongly amongst variables. In addition to the previous study, we compared in a second time the impacts of the presence of shade trees on soil functions and cocoa yield in cocoa farms set up after savannah. To do so, we sampled 5 cocoa monocultures and 8 cAFS. Cocoa yield did not vary between these systems. Nonetheless, the soil P availability was improved in cAFS compared to monocultures. Within cAFS, unshaded cocoa conditions showed the lowest soil functions associated with the low leaf litter quality of cocoa plants. Tree species had contrasting effects on soil functions. Cocoa association with the fruit trees Canarium schweinfurthii and Dacryodes edulis did not improve soil fertility compared with unshaded cocoa, while associations with the legume tree Albizia adianthifolia, or the timber trees Milicia excelsa and Ceiba pentandra significantly improved soil N and P availability. These differences could be explained by the quality of the recycled litter, since low litter recalcitrance was strongly associated with increases in soil N and P availability, while soil pH and soil C contents increased with litter Ca restitution from C. pentandra. Our results highlighted the positive impacts of cAFS establishment in savannah on soil fertility, species diversity and carbon storage in biomass and soil over time. Furthermore, we showed that using specific trees for soil quality and compatible with cocoa, and other trees for the provision of goods, can ensure cocoa AFS multifunctionality and sustainability. Future research will need to understand how plant diversity in these cocoa systems, can help to adapt to climate change. Keywords: Cocoa agroforestry; ecosystem services; forest-savannah transition, litter traits, soil fertilit

Rehabilitation and renovation of cocoa (Theobroma cacao L.) agroforestry systems. A review

In this review, we (1) explore the diversity of contexts, driving forces, stakeholders and recommended management practices involved in Rh/Re initiatives in key cocoa-producing countries; (2) summarise the often conflicting views of farmers and extension agents on Rh/Re programmes; (3) review the evidence of age-related changes in planting density and yield of cocoa, given the weight of these variables in Rh/Re decision processes; (4) describe the best known Rh/Re systems and their most common management practices; (5) propose an agroforestry Re approach that overcomes the limitation of current Rh/Re diagnosis protocols, which do not consider the regular flow of food crop and tree products, and the need to restore site soil quality to sustain another cycle of cultivation of cocoa at the same site; and (6) explore the effects of climate change considerations on Rh/Re decision-making and implementation processes