Introduction: Soil health is critical for the efficient management of soil fertility and crop yield in “green” cocoa (GC) (Theobroma cacao L.) agroforestry systems. However, knowledge about agroecosystem factors that affect healthy soil productivity in “green” cocoa agroforestry systems is patchy in West Africa. Based on organic cocoa (OC) and conventional cocoa (CC) agroforestry systems in Ghana, this study examined the soil health and synergy of ecological factors that determine the yield of GC.Methods: Using multi-stage random sampling, 11 CC and 11 OC farms were sampled from three soil types (ferralsols, lixisols, and leptosols) within selected agroecological zones. Socioeconomic and farm data, including bulked soil samples, were collected at 0–30 cm depth for analysis of soil chemical and physical properties.Results: The results showed intricate relationships between the ecological factors and the yield of GC (1.07 t ha⁻¹), which comprised dry beans of OC (1.24 t ha⁻¹) and CC (0.89 t ha⁻¹). The green cocoa yield increased for fields owned by female farmers and for native farmers who inherited or outrightly owned farmlands. The cocoa yield was also positively related to physicochemical factors such as soil organic carbon (0.21%), pH (5.8), and carbon–nitrogen ratio (40.8%). The carbon–nitrogen ratio and pH together exerted the highest positive influence (0.62%) on the yield. Biological factors such as plant density (>7 cocoa trees per 23.4 m²) and black pod rots reduced the cocoa yield.Discussion: This study provides comprehensive empirical determinants of green cocoa productivity and offers a more reliable estimate of cocoa plant density. The findings suggest that Ghana's cocoa can be much greener if stakeholders promote healthy farm soil productivity and empower women who engage in soil organic carbon-conserving agroforestry.

Open-surfaced water sources have been used to irrigate vegetable farms in cities. Open-surface water often contains unmonitored concentrations of health-threatening contaminants that pose health risks, especially when used to produce vegetables for human consumption. However, information on levels of heavy metals and faecal coliform bacteria in such vegetables in selected sites, especially in Greater Accra Metropolitan Area (GAMA) of Ghana is rare. This study examines the levels of heavy metals and faecal coliform in two vegetables-lettuce and bell pepper - that were cultivated using open-surface wastewater from drains and constructed reservoirs at different locations of the GAMA. Using concurrent mixed methods, questionnaires were administered to 67 vegetable farmers, followed by the collection of vegetable samples from three urban farm sites, Haatso and Dzorwulu and Weija irrigation scheme site (WISS) for laboratory analysis. The concentrations of Lead (Pb), Mercury (Hg) and Cadmium (Cd) were determined using atomic absorption spectroscopy after microwave digestion of the vegetables while total faecal coliform was quantified using MacConkey-Endo broth method. The results from all three sites showed that the concentrations of Cd (=0.001 μg/mg) and Pb (=0.005 μg/mg) in lettuce were within the World Health Organization's (WHO) permissible levels. However, the Hg (≥0.309 μg/mg) and faecal coliform (>5 count/100 ml) in the vegetables from all three sites exceeded the WHO permissible limits. Therefore, consumers of vegetables from such urban farms are exposed to health risks associated with Hg and faecal coliforms. There is the need to intensify education on the health risks of consuming vegetables produced from open-surface water sources from the observed sites. The enforcement of existing phytosanitary standards to enhance food safety and the quality of urban vegetables is also recommended.

The use of kola nut, including natural or alternative medicinal sources, has inevitably created an increased global market demand in excess of its production and provides great prospects for the growth of the kola nut industry in producing countries like Ghana. Nonetheless, there is a great dearth of information on Ghana’s kola nut supply-side practices and constraints that can provide a basis for the development of the industry. This study fills the research gap by describing the practices and constraints of farmers, processors, and marketers of kola nut in Ghana. Using a survey methodology, results showed that nearly all (99.5%) farmers interviewed had not received any extension training on agronomic practices. Low market price of nuts (61.5%) and pests and diseases (60.4%) were the most reported constraints to kola nut production. Chiefs among motivating factors for cultivating kola nut were alternative livelihood support (58%). Some processors (28.6%) who rinsed nuts after depulping used a solution of Akate Master (bifenthrin) and others (51.0%) used fumigation tablets (aluminium phosphide) (91.0%) for storing the nuts. However, these chemicals may be dangerous to the health of consumers in the long run. The low selling price of kola nuts was perceived to be the most (74.8%) constraint to kola nut processing and marketing. Respondents noted that the red nuts were preferred for their durability during transportation and longer shelf life, while the white nuts were preferred for their taste. The results suggest the need for further agronomic, postharvest handling, preservation, and storage, as well as breeding research to provide recommendations to farmers and processors. To overcome some marketing challenges, there is a need for policy support to standardize pricing and grading systems for the mutual benefit of all the stakeholders.

This study investigates the effect of high urban land temperatures on pesticide residue (PR) accumulation in cabbage and lettuce and on public health in the Greater Accra Metropolitan Area (GAMA) in Ghana. A comparative toxicological analysis regarding the food system was conducted with 66 farmers across three land surface temperatures: low (Atomic, n = 22), moderate (Ashaiman, n = 22), and high (Korle-Bu, n = 22). Pesticide residue concentrations were assessed using an ANOVA to examine spatial variations across sites. The results indicate a strong correlation between high land surface temperatures and pesticide residue accumulation, with lettuce recording significantly (p < 0.05) higher PR levels than cabbage. Several pesticides, including carbendazim (CBZ), Imidacloprid (IMI), Thiamethoxam (TMX), and Chlorpyrifos (CHL), exceeded the maximum residue limits (MRLs) set by the World Health Organization (WHO) and the European Union (EU) at moderate and high-temperature sites. carbendazim was the dominant pesticide detected, with a concentration of 19.0 mg/kg in lettuce, which far exceeded its maximum residue limit (MRL) of 0.10 mg/kg across all study sites. Statistical analyses (PERMANOVA) confirmed that land surface temperatures and pesticide types significantly influenced the PR concentrations. Public health risk assessments indicate that children are more vulnerable to pesticide exposure than adults. The toxicity hazard quotient (THQ) for organophosphate pesticides, particularly CHL and Dimethoate (DMT), exceeded safe thresholds at moderate and high-temperature sites.