Title: Agroforestry and Environmental Protection: A Systematic Review of Evidence from Uganda and Sub-Saharan Africa
Authors: Dr. Friday Christopher
Dr.Suzan Luyiga
Prof.Adeyemo David Oluropo
Volume: 10
Issue: 5
Pages: 288-299
Publication Date: 2026/05/28
Abstract:
Background: Integrating trees into farmland known as agroforestry offers a promising approach to tackling environmental issues such as soil degradation, biodiversity decline, climate change, and food shortages. In Uganda, where most farmers are smallholders and environmental damage is widespread, it is vital to understand how well agroforestry works to guide policies and programmes. Objective: This systematic review brings together field evidence on how agroforestry supports environmental protection in Uganda and sub-Saharan Africa. It focuses on soil and biodiversity conservation, carbon storage, climate adaptation, and farmer livelihoods, while also identifying adoption barriers, enforcement weaknesses, and research priorities. Methods: The review followed PRISMA 2020 guidelines. A thorough search was run on Google Scholar, Scopus, Web of Science, PubMed, ScienceDirect, and institutional repositories using terms related to agroforestry, environmental protection, soil, biodiversity, carbon, Uganda, and sub-Saharan Africa. Studies were eligible if they examined agroforestry practices, reported environmental or livelihood outcomes, were conducted in the region, were published from 1999 to 2025, and were in English. Both quantitative and qualitative studies were included, and quality was assessed with appropriate tools such as the CASP checklist. Results: Evidence from thirty-two studies consistently shows positive environmental effects. On soil conservation, research from Ethiopia and Ghana recorded erosion reductions of eighty-seven to ninety-three percent under agroforestry compared to conventional farming. Ugandan studies in the east and west found erosion cuts of up to eighty-four percent, together with improved soil organic matter and structure. For biodiversity, agroforestry systems in the West Nile, Mount Elgon, and Kabale areas supported more plant, bird, and animal species than monocultures. Regarding carbon storage, central Ugandan research showed agroforestry holding up to eight times more carbon than conventional farms, and western Ugandan studies up to five times more. Climate benefits included better drought resistance through higher soil moisture, reduced water loss, and crop shading. Livelihood gains were also reported: farmers practising agroforestry earned more, spent less on inputs, diversified their incomes, and enjoyed greater food security. Nevertheless, adoption remains low due to insecure land rights, scarce seedlings, weak government support, limited knowledge, poor market access, and underfunded extension services. Identified Gaps: Key gaps include missing quantitative data on key mechanisms, no validated local measurement tools, few long-term or experimental studies, vague tree categories, poor understanding of links to nutrition and health, unknown long-term effectiveness, limited site-specific carbon data, questionable relevance of European findings to Uganda, incomplete knowledge of socio-economic adoption factors, fragmented ministry coordination, weak district capacity, and inadequate policy backing.Discussion and Conclusions: Agroforestry clearly contributes to environmental protection by cutting erosion by eighty-four to ninety-three percent, boosting soil fertility, increasing biodiversity, storing three to eight times more carbon than conventional farming, improving drought resilience, and raising incomes and food security. However, success depends on proper implementation, suitable tree species, good training, and supportive policies. Adoption is held back by insecure land tenure, seedling shortages, weak government support, limited technical knowledge, and poor market links. To maximise agroforestry's potential, efforts should focus on strengthening extension services, setting up tree nurseries, securing land rights, embedding agroforestry in national climate plans, creating market links, scaling up proven methods through farmer-to-farmer learning, and conducting rigorous long-term evaluations. Major research needs include longitudinal biodiversity studies, experimental intervention trials, context-specific carbon accounting, and investigations into how agroforestry affects nutrition and health. This review offers a solid evidence base for policymakers, practitioners, researchers, and farmers aiming to use agroforestry for environmental protection and sustainable farming in Uganda and across sub-Saharan Africa.