Efficient utilization of incident solar radiation and rainwater conservation in rain-fed smallholder cropping systems require the development and adoption of cropping systems with high resource use efficiency. Due to the popularity of cassava-maize intercropping and the food security and economic importance of both crops in Nigeria, we investigated options to improve interception of photosynthetically active radiation (IPAR), radiation use efficiency (RUE), soil moisture retention, and yields of cassava and maize in cassava-maize intercropping systems in 8 on-farm researcher-managed multi-location trials between 2017 and 2019 in different agro-ecologies of southern Nigeria. Treatments were a combination of (1) maize planting density (low density at 20,000 maize plants ha^-1 versus high density at 40,000 maize plants ha^-1, intercropped with 12,500 cassava plants ha^-1); (2) fertilizer application and management targeting either the maize crop (90 kg N, 20 kg P and 37 kg K ha^-1) or the cassava crop (75 kg N, 20 kg P and 90 kg K ha^-1), compared with control without fertilizer application. Cassava and maize development parameters were highest in the maize fertilizer regime, resulting in the highest IPAR at high maize density. The combined intercrop biomass yield was highest at high maize density in the maize fertilizer regime. Without fertilizer application, RUE was highest at low maize density. However, the application of the maize fertilizer regime at high maize density resulted in the highest RUE, soil moisture content, and maize grain yield. Cassava storage root yield was higher in the cassava fertilizer regime than in the maize fertilizer regime. We conclude that improved IPAR, RUE, soil moisture retention, and grain yield on nutrient-limited soils of southern Nigeria, or in similar environments, can be achieved by intercropping 40,000 maize plants ha^-1 with 12,500 cassava plants ha^-1 and managing the system with the maize fertilizer regime. However, for higher cassava storage root yield, the system should be managed with the cassava fertilizer regime.

Cassava-maize intercropping is a common practice among smallholder farmers in Southern Nigeria. It provides food security and early access to income from the maize component. However, yields of both crops are commonly low in farmers’ fields. Multi-locational trials were conducted in Southern Nigeria in 2016 and 2017 to investigate options to increase productivity and profitability through increased cassava and maize plant densities and fertilizer application. Trials with 4 and 6 treatments in 2016 and 2017, respectively were established on 126 farmers’ fields over two seasons with a set of different designs, including combinations of two levels of crop density and three levels of fertilizer rates. The maize crop was tested at low density (LM) with 20,000 plants ha⁻¹ versus high density (HM) with 40,000 plants ha⁻¹. For cassava, low density (LC) had had 10,000 plants ha⁻¹ versus the high density (HC) with 12,500 plants ha⁻¹.; The fertilizer application followed a regime favouring either the maize crop (FM: 90 kg N, 20 kg P and 37 kg K ha⁻¹) or the cassava crop (FC: 75 kg N, 20 kg P and 90 kg K ha⁻¹), next to control without fertilizer application (F0). Higher maize density (HM) increased marketable maize cob yield by 14 % (3700 cobs ha⁻¹) in the first cycle and by 8% (2100 cobs ha⁻¹) in the second cycle, relative to the LM treatment. Across both cropping cycles, fertilizer application increased cob yield by 15 % (5000 cobs ha⁻¹) and 19 % (6700 cobs ha⁻¹) in the FC and FM regime, respectively. Cassava storage root yield increased by 16 % (4 Mg ha⁻¹) due to increased cassava plant density, and by 14 % (4 Mg ha⁻¹) due to fertilizer application (i.e., with both fertilizer regimes) but only in the first cropping cycle. In the second cycle, increased maize plant density (HM) reduced cassava storage root yield by 7% (1.5 Mg ha⁻¹) relative to the LM treatment. However, the negative effect of high maize density on storage root yield was counteracted by fertilizer application. Fresh storage root yield increased by 8% (2 Mg ha⁻¹) in both fertilizer regimes compared to the control without fertilizer application. Responses to fertilizer by cassava and maize varied between fields. Positive responses tended to decline with increasing yields in the control treatment. The average value-to-cost ratio (VCR) of fertilizer use for the FM regime was 3.6 and higher than for the FC regime (VCR = 1.6), resulting from higher maize yields when FM than when FC was applied. Revenue generated by maize constituted 84–91% of the total revenue of the cropping system. The highest profits were achieved with the FM regime when both cassava and maize were grown at high density. However, fertilizer application was not always advisable as 34 % of farmers did not realize a profit. For higher yields and profitability, fertilizer recommendations should be targeted to responsive fields based on soil fertility knowledge.

An investigation was conducted at the National Root Crops Research Institute, Umudike and at the Research Farm of Michael Okpara University of Agriculture Umudike, Umuahia, Abia State (Nigeria), to determine the benefit cost analysis of orange fleshed sweet potato (Ipomoea batatas L.) varieties under varying planting density (25,000; 33,333 and 50,000 plants/ha). The output of the production was computed by the use of benefit cost ratio (BCR) of the orange-fleshed sweet potato production. The benefit cost ratio analysis indicated that enterprise was successful and growing of the ‘Melinda’ variety at 50,000 plants/ha was a more profitable enterprise. The benefit cost-cost ratio of ‘Melinda’ variety at 50,000 plants/ha in 2015 and 2016 was 1.45 and 1.56 respectively while that of ‘Tio-joe’ at 50,000 plants/ha in both cropping seasons gave a benefit cost ratio of 1.14 and 1.42 respectively. The returns from selling of the vine cuttings brought about an incredible hike in the net return of the enterprise. ‘Melinda’ at 50,000 plants/ha is recommended to farmers as the most profitable venture in this experiment.

Briquette du Kivu (BdK) is a social enterprise operating in Bukavu, eastern Democratic Republic of the Congo, a region facing persistent food insecurity and environmental degradation linked to prolonged conflict. To reduce dependence on wood-derived cooking fuels and associated deforestation, estimated at approximately 300 hectares of forest lost annually, BdK produces clean-burning charcoal briquettes from locally available organic waste. Because food waste cannot be directly carbonized due to its high moisture content, BdK’s process first employs black soldier fly larvae (BSFL, Hermetia illucens; Diptera: Stratiomyidae) to bio-convert organic substrates into a stabilized residue (frass) while substantially reducing substrate volume. The resulting frass is then carbonized in specialized kilns, mixed with a clay binder, extruded into long cylinders and then sun-dried to produce the final fuel product. In addition to providing a renewable cooking fuel, the system generates protein-rich insect larvae that are sold locally as livestock feed, while a portion of the frass is used as fertilizer in BdK’s fruit tree nursery. The nursery supplies grafted trees to regional households, contributing to food production and supplemental income generation. By integrating waste management, insect bioconversion and fuel production, BdK’s model demonstrates how small-scale circular bioeconomy systems can simultaneously address waste accumulation, energy access and livelihood development in conflict-affected regions.

Chili pepper (Capsicum spp.) plays a crucial cultural, nutritional, and economic role in Senegal, supporting smallholder livelihoods, domestic food systems, and regional export markets. However, post-harvest losses associated with traditional open-air drying and storage remain high, particularly under coastal conditions characterized by high relative humidity and variable weather. Improving drying assessment and storage practices is therefore essential to enhance chili quality, safety, and marketability. This study evaluated smallholder chili drying and storage practices in Senegal, with a particular focus on processor dryness judgment, drying surfaces, and storage materials, and assessed the potential role of a simple equilibrium relative humidity (ERH)-based decision-support tool. A participatory, on-farm study was conducted with six chili processors in the Niayes agroecological zone of western Senegal. Freshly harvested chilies were dried concurrently using black plastic sheeting and processors’ customary drying materials under farmer-managed conditions. Processor assessments of storage readiness were compared with ERH-based classifications using the DryCard tool. Drying duration and dry matter content were recorded for each treatment. Dried chilies were subsequently stored in either airtight glass jars or traditional gunny bags, and weight changes were monitored at 25, 45, and 70 days after storage. Data were analysed descriptively using within-processor comparisons to identify consistent patterns across sites. After 15 days of drying, all chili samples were classified as not dried for storage, with DryCard readings of approximately 75% ERH across sites. Final processor-determined drying durations ranged from 29 to 42 days. DryCard ERH values at this stage ranged from 30% to 70%, with three instances where processor judgement indicated storage readiness despite ERH values exceeding the 65% threshold. Dry matter content varied widely across treatments and sites, ranging from 7.4% to 18.3%. Chilies dried on black plastic sheeting showed higher and more consistent dry matter content (median ≈ 11.5%) compared with chillies dried on processor-preferred materials (median ≈ 9.1%). During storage, chilies kept in airtight glass jars maintained stable weights close to the initial 200 g over 70 days (199–201 g). In contrast, those stored in gunny bags showed progressive weight increases, reaching median values of approximately 208.5 g after 70 days. The study demonstrates that while experiential knowledge remains central to smallholder chili processing, it can be strengthened with simple, objective tools that support more reliable drying and storage decisions. Incremental improvements in drying surface selection, combined with ERH-based assessment and moisture-limiting storage, offer practical pathways for reducing post-harvest losses and quality risks. These context-appropriate interventions can enhance the safety, stability, and economic value of dried chilies without requiring costly infrastructure, making them well-suited to smallholder systems in humid environments.