Inclusive business models (IBM) connect smallholders and other low-income people with buyers, processors and traders in agricultural and forest product value chains. Value chain actors engage with each other through diverse institutional arrangements, including international (e.g. UN Global Compact, zero deforestation) and industry standards (e.g. Roundtable on Sustainable Palm Oil, Cocoa and Forests Initiative), certifications (e.g. fair trade, organic), and contract farming.
Tag: cocoa
Combined effects of shade and drought on physiology, growth, and yield of mature cocoa trees
Climate models predict decreasing precipitation and increasing air temperature, causing concern for the future of cocoa in the major producing regions worldwide. It has been suggested that shade could alleviate stress by reducing radiation intensity and conserving soil moisture, but few on-farm cocoa studies are testing this hypothesis. Here, for 33 months, we subjected twelve-year cocoa plants in Ghana to three levels of rainwater suppression (full rainwater, 1/3 rainwater suppression and 2/3 rainwater suppression) under full sun or 40 % uniform shade in a split plot design, monitoring soil moisture, physiological parameters, growth, and yield. Volumetric soil moisture (ϴw) contents in the treatments ranged between 0.20 and 0.45 m3m−3 and increased under shade. Rainwater suppression decreased leaf water potentials (ѱw), reaching −1.5 MPa in full sun conditions indicating severe drought. Stomatal conductance (gs) was decreased under the full sun but was not affected by rainwater suppression, illustrating the limited control of water loss in cocoa plants. Although pre-dawn chlorophyll fluorescence (Fv/Fm) indicated photoinhibition, rates of photosynthesis (Pn) were highest in full sun. On the other hand, litter fall was highest in the full sun and under water stress, while diameter growth and carbon accumulation increased in the shade but was negatively affected by rainwater suppression. Abortion of fruits and damage to pods were high under shade, but dry bean yield was higher compared to under the full sun. The absence of interactions between shade treatments and rainwater suppression suggests that shade may improve the performance of cocoa, but not sufficiently to counteract the negative effects of water stress under field conditions.
Farm Rejuvenation-Induced Changes in Tree Spatial Pattern and Live Biomass Species of Cocoa Agroforests in Central Cameroon: Insights for Tree Conservation Incentives in Cocoa Landscapes
Cocoa agroforests sustain ecosystem services (ESs) to varying degrees. These services are otherwise mostly provided by other non-cocoa shade or companion trees. However, the density of shade trees is associated with services and/or disservices that drive farm-specific tree management successions. Considering the growing impacts of climate crisis on farm productivity and the need for adaptation strategies, the ESs are increasingly provisional and contingent on the prevailing vegetation, land tenure, and management successions, amongst others social and ecological factors. To assess the temporal changes in shade management, we surveyed an age gradient of “family farms” in cocoa agroforests created from forest (fCAFS) and savannah (sCAFS) land cover. We evaluated the temporal changes in farm structure, relative tree abundance, and live aboveground biomass of the major canopy strata. We used a spatial point process and linear mixed effect analysis to assess the contributions of associated perennial trees (AsT) on farm rejuvenation patterns. The density of cocoa trees was inconsistent with farm age; this was significantly high on farms in sCAFS (1544 trees ha−1) with spatially random configuration across farm age. On farms in fCAFS, we observed a transition of the cocoa tree configuration in the order regular, random, and clustering from young (with highest density of 1114 trees ha−1) to old farms. On a temporal scale, there is no clear distinction of farm structure and biomass between fCAFS and sCAFS. However, the cycle of tree species and structural composition of the canopy strata are dissimilar; the live biomass allocation for the considered use groups of tree species was different with farm age. The observed dynamics in canopy tree structure and live biomass provide insights into farmers’ temporal allocation of uses and prioritization of different tree species with farm age. We recommend the consideration of such landscape-specific, tree management dynamics in proposing on-farm tree conservation incentives. Our results are also conducive to reliable estimates of the ecosystem services from CAFS in the national implementation of conservation mechanisms such as REDD+.
Litterfall seasonal dynamics and leaf-litter turnover in cocoa agroforests established on past forest lands or savannah
Nutrient cycling in cocoa agroforestry systems (cAFS) is complex and poorly understood. To better understand the mass flow of carbon and nutrients into the soil sub-system under various contexts we quantified the mass flow of litterfall, its composition and seasonal variations in different agroforestry systems in Bokito (Central Cameroon). We studied litterfall dynamics and in situ leaf-litter cycling of cAFS established on past forest lands (F-cAFS) and savannah (S-cAFS). We also studied the decomposition of cocoa and associated tree leaf-litter in litterbags. Local secondary semi-deciduous forests were included as control. Annual litterfall in full-grown cAFS (> 15 years old) was high (9.4 Mg ha−1 y−1) and represented ca. 67% of litterfall in control forests. In full-grown cAFS, associated tree leaf-litter contributed to litterfall the most and ranged between 60 and 70% of the total amount recorded (6.3 Mg ha−1 y−1). The quantities and dynamics of the litter components monitored were similar in full-grown S- and F-cAFS. The microclimate was best buffered in forests and least buffered in young S-cAFS but could not be linked to leaf-litter decomposition. Forest leaf litterfall was higher and tended to cycle faster than total leaf-litter of cAFS, whose decomposition appeared limited by cocoa leaf-litter quality. Our study underlines (i) the critical contribution of associated trees to the nutrient cycle of agroecosystems established on poor soils and, (ii) the ability of farmers to channel associated tree communities towards similar functioning despite different past land-uses.
Does sentinel-1A backscatter capture the spatial variability in canopy gaps of tropical agroforests? A proof-of-concept in cocoa landscapes in Cameroon
A reliable estimation and monitoring of tree canopy cover or shade distribution is essential for a sustainable cocoa production via agroforestry systems. Remote sensing (RS) data offer great potential in retrieving and monitoring vegetation status at landscape scales. However, parallel advancements in image processing and analysis are required to appropriately use such data for different targeted applications. This study assessed the potential of Sentinel-1A (S-1A) C-band synthetic aperture radar (SAR) backscatter in estimating canopy cover variability in cocoa agroforestry landscapes. We investigated two landscapes, in Center and South Cameroon, which differ in predominant vegetation: forest-savannah transition and forest landscape, respectively. We estimated canopy cover using in-situ digital hemispherical photographs (DHPs) measures of gap fraction, verified the relationship with SAR backscatter intensity and assessed predictions based on three machine learning approaches: multivariate bootstrap regression, neural networks regression, and random forest regression. Our results showed that about 30% of the variance in canopy gap fraction in the cocoa production landscapes was shared by the used SAR backscatter parameters: a combination of S-1A backscatter intensity, backscatter coefficients, difference, cross ratios, and normalized ratios. Based on the model predictions, the VV (co-polarization) backscatter showed high importance in estimating canopy gap fraction; the VH (cross-polarized) backscatter was less sensitive to the estimated canopy gap. We observed that a combination of different backscatter variables was more reliable at predicting the canopy gap variability in the considered type of vegetation in this study—agroforests. Semi-variogram analysis of canopy gap fraction at the landscape scale revealed higher spatial clustering of canopy gap, based on spatial correlation, at a distance range of 18.95 m in the vegetation transition landscape, compared to a 51.12 m spatial correlation range in the forest landscape. We provide new insight on the spatial variability of canopy gaps in the cocoa landscapes which may be essential for predicting impacts of changing and extreme (drought) weather conditions on farm management and productivity. Our results contribute a proof-of-concept in using current and future SAR images to support management tools or strategies on tree inventorying and decisions regarding incentives for shade tree retention and planting in cocoa landscapes. © 2019 by the authors. Licensee MDPI, Basel, Switzerland.
Biodiversity of the cocoa agroforests of the Bengamisa-Yangambi Forest Landscape in the Democratic Republic of the Congo (DRC)
Cocoa agroforestry has evolved into an accepted natural resource conservation strategy in the tropics. It is regularly proposed as one of the main uses for REDD+ projects (Reducing Emissions from Deforestation and forest Degradation and the role of conservation, sustainable management of forests, and enhancement of forest carbon stocks in developing countries) in the Democratic Republic of the Congo. However, few studies have characterized the cocoa agroforestry systems in this country. Hence, this research proposes to determine the impact of distance from Kisangani (the unique city in the landscape) and land-use intensity on the floristic composition of cocoa agroforests in Bengamisa-Yangambi forest landscape in the Congo Basin. The results revealed that species diversity and density of plants associated with cocoa are influenced by the distance from Kisangani (the main city in the landscape and province). Farmers maintain/introduce trees that play one or more of several roles. They may host caterpillars, provide food, medicine, or timber, or deliver other functions such as providing shade to the cocoa tree. Farmers maintain plants with edible products (mainly oil palms) in their agroforests more than other plants. Thus, these agroforests play key roles in conserving the floristic diversity of degraded areas. As cocoa agroforestry has greater potential for production, biodiversity conservation, and environmental protection, it should be used to slow down or even stop deforestation and forest degradation.
Can cocoa agroforestry restore degraded soil structure following conversion from forest to agricultural use?
Alternating degradation and restoration phases of soil quality, as is common in crop-fallow systems, can be avoided if the restorative elements of trees and forests can be integrated into productive agroforestry systems. However, evidence for the hypothesis of ‘internal restoration’ in agroforestry is patchy and the effectiveness may depend on local context. We investigated to what extent cocoa (Theobroma cacao, L.) agroforestry can recover soil structure and infiltration in comparison to monoculture systems across the Konaweha Watershed, Southeast Sulawesi. We compared soil organic carbon, fine root length and weight, soil aggregate stability, macroporosity and infiltration from three soil layers at five land use systems: i.e. degraded forests, 9–14 years old of complex-cocoa agroforestry, simple-cocoa agroforestry, monoculture cocoa and 1–4 years old annual food crops, all with three replications. In general, roots were concentrated in the upper 40 cm of soil depth, contained of 70% and 86% of total fine root length and weight. Compared to simple agroforestry and cocoa monoculture, complex agroforestry had greater root length and weight in the topsoil, even though it attained only half the values found in degraded forests. Higher root density was positively correlated to soil organic carbon. In upper soil layers, complex agroforestry had slightly higher soil aggregate stability compared to other agricultural systems. However, no significant difference was found in deeper layers. Complex agroforestry had higher soil macroporosity than other agricultural systems, but not sufficient to mimic forests. Degraded forests had two times faster steady-state soil infiltration than agricultural systems tested (13.2 cm h−1 and 6 cm h−1, respectively), relevant during peak rainfall events. Compared to other agricultural systems, complex agroforestry improves soil structure of degraded soil resulting from forest conversion. However, a considerable gap remains with forest soil conditions.
Do farmers’ perceptions and socio-economic factors drive cocoa agroforestry and sustainable soil carbon management practices in West Africa?
We evaluated the farmer’s local knowledge and perceptions of sustainable cocoa agroforestry and sustainable soil carbon management in Ghana and Côte d’Ivoire using a social survey research methodology. We employed in-depth interviewing and focus group discussions to solicit information from identified key stakeholders in the cocoa supply chain focusing on the perception of sustainable cocoa agroforestry and soil carbon management. Our results revealed that about 83% and 50.5% of smallholder cocoa farmers from Côte d’Ivoire and Ghana respectively practiced agroforestry on their farms. The respondents, however, had limited knowledge about the term agroforestry and were also not very much aware of soil carbon management. Also, about 53% and 22% of the respondents from Côte d’Ivoire and Ghana perceived agroforestry practice as better than practicing cocoa monoculture. The results further revealed that most of the cocoa farmers in these study areas had limited knowledge of the approaches or strategies to achieve sustainable cocoa agroforestry and soil carbon management on their farms. At the same time, the industry’s stakeholders had different perceptions about the approaches or strategies to achieve these. Our results also revealed that educational level was the only socio-economic factor that influenced the farmer’s awareness of agroforestry and soil organic carbon. This study thus suggests the need for appropriate training and education for smallholder cocoa farmers, and harmonization of the understanding among different stakeholder groups along the cocoa supply chain of common strategies to adopt to achieve sustainable cocoa production that addresses low productivity, biodiversity loss and carbon emission within the smallholder cocoa production system in West Africa.
Effect of Proper Management of Cocoa Plants on the Occurrence of Swollen Shoot Disease in Kipiri – Côte d’Ivoire
This study aimed to evaluate the relationship between plot maintenance level and the prevalence of Cocoa swollen shoot disease in Kipiri (Department of Soubré) in Côte d’Ivoire. Indeed, the strong pressure of Swollen shoot disease in this department causes enormous damage in cocoa plots.The study design is a prospective survey in peasant cocoa plots between 2014 and 2016. The data were collected using the Land Degradation Surface Framework (LDSF). The LDSF device is a sentinel site of 10 Km × 10 Km. The site is divided into 16 Clusters of 2.5 Km × 2.5 Km with 10 plots by cluster. In the case of our study, surveys were carried out on 108 plots carrying cocoa trees within a radius of 50 m around each test plot. The data collected included areas of Cocoa Swollen Shoot Virus (CSSV) outbreaks, the cocoa plot maintenance level and CSSV status like ‘Absence’ or ‘Presence’ in plots observed. CSSV prevalence was deduced from CSSV outbreaks areas of each sampling plot, allowing realization of disease map. The relationship between the level of plot maintenance and the prevalence of CSSV was assessed by using the analysis of variance test (Anova-one-way). The results of Swollen shoot disease’s distribution showed that the Kipiri site had a CSSV prevalence around 50%.These results demonstrated that plots maintenance level has a strong influence on the prevalence of Swollen shoot disease (p =0.00 < 0.05). At the end of this study, it appears that plots maintenance level is a key factor in the rapid spread of the Swollen shoot epidemic in Kipiri site. Cocoa producers would therefore be recommended to regularly maintain their plantations by eliminating the reservoirs of Cocoa Swollen Shoot Virus.
Variations in yield gaps of smallholder cocoa systems and the main determining factors along a climate gradient in Ghana
Improving management practices of cocoa (Theobroma cacao L.) cultivation especially under future climate change requires knowledge of yield gaps and their determining factors. In this study, we assessed yield gaps and their determining factors through multiple regression modelling in smallholder cocoa agroforestry systems in Ghana along a climatic gradient. The studied zones referred to as dry, mid and wet with annual rainfall of 1200, 1200–1400 and 1400–2000 mm respectively, represent established “climate suitability zones” across the cocoa belt of West Africa, where 70% of the global cocoa is produced. Data was collected from 150 cocoa farmers and their plantation across the zones. Information about socioeconomic and management characteristics was collected through interviews. In each plantation, soil characteristics and cocoa plantation properties were recorded. Yield data for three consecutive years (2012/13–2014/15) and soil properties (0–30 cm layer) were analysed. Yield gap was estimated as the difference between attainable yield (AY) and actual farmers yield (FY) in each zone based on the approach of maximum farmer yields determined from survey. Average farmer and attainable yield of 211 and 645 kg ha−1 year−1 in the dry, 477 and 1174 kg ha−1 year−1 in the mid and 999 and 2125 kg ha−1 year−1 in the wet zone were recorded, respectively. Relative yield gaps were significantly larger in the dry (67%) than the wet zone (53%). In the dry zone with significantly older farmers (average age of 64), increasing labour cost (use of hired labour) significantly reduced yield gap. Contrary, increasing labour cost significantly increased yield gap in the mid zone where plantations were significantly larger. Yield gap increased significantly with increasing farmer age (54 years) in the mid zone but decreased significantly with farmer age (47 years) in the wet zone. Significant positive relationship between plantation size and yield gap was observed in both mid and wet zones. Soil available phosphorous (P) and fungicide use significantly reduced yield gap in the dry and mid zones. Finally, quantity of pesticide, proportion of hybrid cocoa plants and number of trainings received by farmers significantly reduced yield gap in the wet zone. In the dry zone, closing the yield gap against the climate risk might be unlikely. Transformation into more drought resistant systems such as cashew might be promising. However, in the mid and wet zones, labour availability for effective management of large plantations might be the major barrier for intensification, which needs to be addressed by intervention strategies.