The conventional linear system of global food production and consumption is unsustainable as it is responsible for a substantial share of greenhouse gas emissions, biodiversity declines due land use change, agricultural water stress due resource-intensive water consumption patterns and land degradation. During the last decade (1994–2014), for example, the greenhouse emissions from agriculture in Africa were reported to increase at an average annual rate of between 2.9% and 3.1%, equivalent to 0.44 Gt and 0.54 Gt CO₂ per annum, respectively. Between 2000 and 2020, the greenhouse gas emissions from agrifood systems were shown to decrease in all major regions of the world, except in Africa and Asia, where they grew by 35 and 20 percent, respectively. With most of the circular agricultural practices still central to food production in the developing African countries, the continent can spearhead a global return to circular agriculture. Using a descriptive review approach, we explore the literature to examine the extent to which African agriculture is deploying these practices, the potential areas for improvement and lessons for the world in embracing sustainable food production. We underscore that the farming communities in sub-Saharan Africa have, for decades, been using some of the most effective circular agricultural principles and practices in agricultural production. We further show that practices and strategies akin to sustainable agricultural production include agronomic practices, smart irrigation options, renewable energy harvesting and waste-to-fertilizer technologies. All of these technologies, which are central to sustainable agricultural production, are not new to Africa, although they may require packaging and advocacy to reach a wider community in sub-Saharan Africa.

Smallholder farmers in Ethiopia, Malawi and Tanzania are under pressure to sustainably improve agricultural production and manage the environment due to limited access to agricultural inputs. Limited application of biochar among farmers is caused by scattered research findings. Thus, the focus of this review is to critically analyze the current state of knowledge regarding biochar technology in the cases of Ethiopia, Malawi, and Tanzania. The smallholder farmers in these countries commonly use cheap and portable tools and techniques with low cost for biochar production such as open pile burns and open earth pit-based biochar production. Depending on the availability of labor and farming system, farmers apply biochar in the fields by either broadcasting, furrow application, band placement, spot placement, or ring application. Farmers also integrate biochar with co-composting with nutrient-rich manure, and animal and human urine for soil fertility management. Several studies have confirmed that biochar has a great role in sustaining agriculture through improving soil fertility, crop production, adsorbing pollutants, and mitigating climate change. Biochar is also an important feed additive when mixed with animal diets for cattle, poultry, pigs, and fish, and improves the quality and amount of animal production. However, feed stock resources competition of crop residue for biochar is less preferred than its use for animal feed, mulching under conservation agriculture. Use of wood for biochar production may cause deforestation and degradation. Use of alternative resources such as invasive plant species and organic wastes for biochar production is important. The smallholder farmers hold diverse perceptions about biochar, shaped by their experiences, knowledge, and socio-economic context. In general, biochar is an input for amendment of degraded soils, maintenance of long-term soil functions and carbon sequestration in a soil and reduction of GHG emissions in developing countries.

Soil contamination in Sub-Saharan Africa (SSA) is increasingly driven by rapid industrialization, intensive agriculture, mining activities, and urban expansion, posing significant risks to food safety, ecosystem services, and human livelihoods. Despite the growing scale of the problem, low-cost, locally adaptable remediation technologies are widely available and technically feasible within the region. Organic waste and waste-derived products—such as compost, manure, biochar, vermicompost, digestate, and agro-industrial residues—have emerged as sustainable and cost-effective amendments for the remediation of contaminated soils. These materials can immobilize heavy metals, enhance the microbial degradation of organic pollutants, and improve soil health, making them especially suitable for resource-constrained settings. This review synthesizes the current knowledge on the use of organic waste-based remediation approaches in SSA, highlighting technologies already applied at the laboratory, pilot, and field scales, as well as their effectiveness across different contaminant types. However, despite their demonstrated potential, their widespread adoption remains limited. The primary challenge is not the absence of affordable solutions, but rather the systemic constraints characteristic of many SSA countries, including limited technical capacity, weak policy and regulatory frameworks, low stakeholder awareness, and insufficient financial and institutional support for large-scale implementation. To enable broader uptake, there is a need to strengthen waste segregation and treatment systems, standardize composting and pyrolysis processes, and develop robust regulatory guidelines and certification schemes. Investments in monitoring infrastructure, practitioner training, and knowledge transfer mechanisms will also be critical to translating scientific advances into scalable, field-ready solutions for sustainable soil remediation in SSA.

A study was conducted to test the potential of calabash, sweet potato, pumpkin, simsim and finger millet to phytoaccumulate dichlorodiphenyltrichloroethane (DDT) and its metabolites from NHC Morogoro- and PPO Tengeru-contaminated sites. Parallel field and screenhouse-potted soil experiments were performed to assess the efficacy with which the test plants phytoaccumulate DDT from the soil. In the screenhouse experiment, treatments were laid out following a split-plot arrangement in a completely randomized design (CRD), with the main plots comprising two DDT concentration levels–low (417 mg kg⁻¹) or high (2308 mg kg⁻¹)—and the plant species Cucurbita pepo, Lagenaria siceraria, Ipomoea batatus, Sesamum indicum and Eleusine coracana were considered as subplots. A field experiment with the same crop species as the treatments was laid out in a randomized complete block design, and both experiments were performed in triplicate. In addition to determining the concentration of persistent organic pesticides in the soil profile, parameters such as the total DDT uptake by plants, shoot weight and shoot height were monitored in both potted soil and open field experiments. Overall, calabash and sweet potato exhibited the highest (4.63 mg kg⁻¹) and second highest (3.45 mg kg⁻¹) DDT concentrations from the high residual DDT potted soil experiment. A similar trend was observed when the two plants were grown in low DDT soil. Sweet potato recorded the highest shoot height and weight in the potted soil experiments, indicating that increasing amounts of DDT had a minimal effect on the plant’s growth. Although sweet potato outperformed calabash in the amounts of DDT concentration in the shoots under open field experiments, the uptake of DDT by calabash was the second highest. Calabash—a wild non-edible plant in Tanzania—presents a potential phytoremediation alternative to edible and much studied pumpkin.

Irish potato (Solanum tuberosum) is a critical crop for food security and economic growth in Tsangano and Angónia Districts, Central Mozambique. Challenges like inconsistent yields and variable quality are often linked to suboptimal soil conditions, which limit production. This study aimed to classify and evaluate the suitability of soils for potato cultivation in Tete Province, where detailed soil assessments remain limited. Four pedons—TSA-P01 and TSA-P02 in Tsangano and ANGO-P01 and ANGO-P02 in Angónia—were examined for bulk density, texture, pH, organic carbon, and nutrient content using a combination of pedological methods and laboratory soil analysis. To determine each site’s potential for growing Irish potatoes, these factors were compared to predetermined land suitability standards. The pedons were very deep (>150 cm) and had textures ranging from sandy clay loam to sandy loam. TSA-P02 had the lowest bulk density (0.78 Mg m⁻³) and the highest available water capacity (182.0 mm m⁻¹). The soil pH ranged from 5.6 to 7.9, indicating neutral to slightly acidic conditions. Nutrient analysis revealed low total nitrogen (0.12–0.22%), varying soil organic carbon (0.16–2.73%), and cation exchange capacity (10.1–11.33 cmol⁽⁺⁾ kg⁻¹). Pedons TSA-P01, ANGO-P1, and ANGO-P02 were characterized by eluviation and illuviation as dominant pedogenic processes, while in pedon TSA-P02, shrinking and swelling were the dominant pedogenic processes. Weathering indices identified ANGO-P01 as most highly weathered, while TSA-P02 was least weathered and had better fertility indicators. According to USDA Taxonomy, the soils were classified as Ultisols, Vertisols, and Alfisols, corresponding to Acrisols, Alisols, Vertisols, and Luvisols in the WRB for Soil Resources. All studied soils were marginally suitable for potato production (S3f) due to dominant fertility constraints, but with varying minor limitations in climate, topography, and soil physical properties. The findings hence recommended targeted soil fertility management to enhance productivity and sustainability in potato cultivation.