Implications of a Climate-Smart Approach to Food and Income Security for Urban Sub-Saharan Africa: A Systematic Review

Abstract

Climate change presents a significant threat to humanity. It affects agriculture, food supply, and economic development. Urban agriculture (UA) is an alternate climate-smart approach to enhancing food and income security. The climate-smart agriculture (CSA) concept promises to lessen the effects of climate change. Nuanced research is critical to warrant food and income security. This review paper synthesises evidence through a systematic literature search to analyse the implications of CSA practices and climate adaptation strategies for food and income prospects. We also employed bibliometric analysis to show emerging trends and identify knowledge gaps in the ongoing topical discourse. The review elucidates insights into how CSA practices boost urban food production, accessibility, and dietary diversity, ultimately enhancing urban farmers’ food security. The economic benefits of CSA and climate adaptation strategies highlight that UA is vital for improving urban farmers’ income. Despite the opportunities created by UA, the review recognises the critical challenges and trade-offs that call for transforming UA to safeguard food and income security in the face of increasing climate change. The review calls for an all-round UA transformation encompassing urban community-based efforts, capacity building, and policy support mechanisms aimed at advancing climate-resilient UA and ensuring food and income security in an ever-changing environment.

1. Introduction

The increasing challenges brought about by climate change have implications for agriculture; they especially impact farmers in developing countries with less capacity to cope with climate change [1]. Unsustainable farming practices contribute to greenhouse gas emissions and increase exposure to climate change-related threats that disrupt food systems and affect livelihoods, particularly those of resource-poor farmers [2,3,4,5,6,7,8].

In Sub-Saharan Africa (SSA), small-scale farmers are most likely to be affected by the direct impacts of climate change. Climate change impedes endeavours to attain food security amid rising urbanisation and population growth [8,9,10]. The ever-increasing threat of food insecurity calls for urgent climate action to mitigate the effects of escalating food demand [11].

As the global population increases, food insecurity will intensify the demand for food in urban areas, thus exerting pressure on officials to import more food [12]. There is already enough evidence showing that, in less developed regions, such as Africa, the repercussions of climate change on crop production and food security are immense [13,14,15]. Sustainable agriculture is critical for dealing with the negative implications of climate change for agriculture and food and nutrition security [16].

Researchers have proposed numerous approaches to improving food production. However, unintended consequences such as deforestation, land degradation, ineffective water use, and biodiversity loss have been observed [17,18,19,20,21,22]. Increasing urbanisation dislocates agricultural production by decreasing agricultural land area [23]. This poses a complex challenge and requires innovative climate-smart agricultural production approaches to ensure sustained food production and livelihoods [24].

Urban agriculture (UA) is central to the urbanisation and climate change discourses as a tool for enhancing food insecurity resilience and promoting sustainable food systems, including economic development in urban areas [25]. Given some of the complexities presented by urbanisation, UA design should be viable and a pathway to improving food production and promoting local economies [26]. Urban agriculture promises climate-smart approaches to farming, such as community gardens, rooftop gardens, urban greenhouses, and vertical farming, that are appropriate to the unique urban context’s spatial challenges and opportunities [27]. Urban agriculture promises balanced biodiversity, fresh produce, nutritious agricultural products, and efficient waste management (composting) [28]. These promises could mitigate the effects of urban heat islands through urban greening (cover crops and green spaces) [29,30]. UA also reinforces urban community and social cohesion among urban farmers in the context of the common goal of enhancing food production and sustainability [31]. In the face of the climate change challenge, UA has become a resilient food system and an alternative to conventional rural agricultural systems [32]. Urban agriculture offers farmers options for low-cost, innovative, and sustainable practices, such as hydroponics and aquaponics, which can improve yields and use water efficiently (less water), as well as soilless techniques. These options minimise the challenges of scarce urban land and water sources [33,34,35]. Further, UA systems could benefit cities with renewable energy, minimising the carbon footprint of urban food production [36]. The urge to improve food security and alleviate poverty amid a growing urban population is pertinent in developing countries [37]. Due to reduced transportation and distribution expenses, supplying a diversity of fresh and nutritious foods from urban farms at a low cost promises to combat food insecurity in urban areas [38]. Local production cushions urban areas against global food price shocks and supply chain disruptions, enhancing urban food systems’ resilience against the adverse effects of climate change [39].

Additionally, recognising the challenges of UA uptake as a climate-smart approach is critical. Health risks linked to pollution and food contamination from wastewater use are cited among the UA challenges. Low-resource urban farmers also contend with a lack of capital for acquiring necessary resources. Increased industrialisation has led to a greater number of structures in urban areas that take up potential space for UA. Again, small-scale urban farmers are constrained by the know-how, limiting urban regulatory frameworks and water access issues. Fully optimising the potential of UA in achieving food and income prospects calls for concerted action from all stakeholders, including urban planners [40]. Undeniably, UA sustainability will require adopting best practices in resource management, waste reduction, and environmental protection, with insights by Bennedetti et al. [41] interwoven into the broader urban planning, ecology, and policy framework to support UA and lessen practical challenges [42,43]. With the forgoing discussion, UA promises a vital framework for achieving sustainable food systems and economic development in urban areas in the face of the climate change debacle.

In light of recognising the significance of sustainable practices, the concept of climate-smart agriculture (CSA) was introduced in 2009 [44]. Climate-smart agriculture’s role is to reinforce the Sustainable Development Goals (SDGs) on food security by enhancing resilience (SDG1: no poverty and SDG2: zero hunger), lowering greenhouse gas emissions (SDG 7: affordable and clean energy and SDG 13: climate action), and sustainably boosting outputs and incomes (SDG 8: decent work and economic growth and SDG 12: responsible consumption and production) [45]. The building blocks or pillars of CSA are adaptation, mitigation, and productivity, offering a comprehensive framework for eradicating hunger and food insecurity in the wake of climate change [46,47,48]. In this regard, CSA is an essential global strategy for mitigating and minimising the effects of climate change, especially in less developed areas primarily relying on agriculture. The relevance of CSA is in minimising the carbon footprint (fewer greenhouse gas emissions) while scaling up on sustainable farming practices and increasing the resilience of farmers. In this context, CSA is a framework for mitigating food insecurity and climate-related risks on a larger global scale. A climate-smart approach, therefore, is paramount to nurturing agricultural sustainability that will safeguard food and income security amidst the rising population growth, urbanisation, and developmental stresses. However, while adopting CSA practices has gained momentum and is recognised worldwide, low-income countries, particularly in the SSA region, are still battling socio-economic challenges, food and nutrition security issues, and income difficulties due to increasing climatic conditions.

Based on the climatic threat posed by climate change and global warming, the current systematic review paper examines the implications of CSA for food and income security in the context of urban settings in SSA by small-scale urban farmers. In general, climate-smart farming practices or climate adaptation mechanisms promote resilient food systems through enhanced productivity, sustained production, and income generation opportunities. However, there is limited research that demonstrates the implications of CSA or climate adaptation for food and income generation in the SSA region. Therefore, this review systematically synthesises the relevant CSA or climate change adaptation research conducted across the SSA region over the past 20 years, demonstrating the significance of CSA to urban food production, farmer income enhancement, and environmental sustainability. This review critically underlines the implications of urban small-scale farmers investing in CSA while acknowledging pertinent challenges as well as the need for urban policy support or a framework for addressing the emerging problem of urban food and income insecurity due to urbanisation. Specifically, the objectives of this review paper are to (1) illustrate some key trends and identify knowledge gaps concerning the CSA practices in SSA, particularly for UA, and (2) explore the implications of CSA practices for small-scale urban farmers’ food and income security.

2. Materials and Methods

2.1. Search Strategy, Inclusion and Exclusion Criteria

Figure 1 portrays the systematic literature review employing the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) recommendations. The review uses two databases, EBSCOhost and Scopus, to search for relevant articles concerning the implications of CSA practices and climate adaptation strategies for food and income security in SSA countries. Although using a greater number of databases could be preferable, the EBSCOhost and Scopus databases are renowned for enhancing the breadth and depth of the search, improving the interdisciplinary scope, and allowing for advanced search, which contributes to the rigour and reliability of the search findings. Scopus is one of the largest databases for research. The EBSCOhost database provides access to a massive and varied collection of scholarly journals. The EBSCOhost and Scopus databases were chosen because of their friendly user interface and capacity to offer powerful search features. A search through EBSCOhost (the University of Zululand library institutional access) using the search terms; “climate-smart agriculture” OR “climate change adaptation” AND “food security” AND “income security” AND “urban agriculture” OR “urban farming” resulted in 6859 search results. Refining and limiting the search using the limiters “Full Text”, “Publication Date: 1 January 2003 to 31 December 2023”, “Source Types: Academic Journals”, “Language: English”, “Geography: Africa South of the Sahara, Cote d’Ivoire, Ethiopia, Ghana, Kenya, Malawi, Nigeria, Senegal, South Africa, Sub-Saharan Africa, Tanzania, Togo Uganda, Zambia” and resulted in 187 articles. After removing duplicates, 104 articles remained. A search through Scopus (the University of Zululand library institutional access) using the search terms; “climate-smart agriculture” OR “climate change adaptation” AND “food security” AND “income security” AND “urban agriculture” OR “urban farming” resulted in 782 documents found. Refining and limiting the Scopus search to full text, with a publication range of 2003 to 2023, resulted in 232 academic journal articles published in English and the Sub-Saharan Africa region. Further screening of the full texts resulted in 46 and 25 articles for EBSCOhost and Scopus, respectively.

The inclusion and exclusion criteria applied in this systematic review limited the results to those articles published from 2003 to 2023, in full-text English and in peer-reviewed journal, that focus on urban or peri-urban and semi-urban contexts. Articles related to peri-urban or semi-urban agriculture and CSA met the inclusion criteria as they provided valuable insights. We excluded duplicate articles, focusing exclusively on rural settings (not considering peri-urban or urban areas), not in the SSA region, and not emphasising the nexus between CSA and food or income security. The final number of articles synthesised and considered in this review paper was 50 (39 from EBSCOhost and 11 from Scopus) after implementing the inclusion and exclusion criteria, having assessed the articles for eligibility and removed duplicate articles/entries. This current systematic review also incorporated a bibliometric analysis concentrating on bibliometric data, for example, unit publications and citations in CSA research and co-occurrence and interlinkages among keywords. The analysis in this review benefited from bibliometric software, VoSviewer version 1.6.19, and Bibliometrix (Biblioshiny) packages (https://www.bibliometrix.org/home/) [49] based on RStudio Desktop version 4.3.1, which simplified the analysis of the bibliographic datasets. We saved the articles retrieved through the EBSCOhost and Scopus databases and exported them to the bibliometric packages as raw files .BIB (Bib Tex) file types. The bibliometric software/packages enabled the exploration of research growth in the domain under investigation and the development patterns or trends in the scholarly landscape. In short, the bibliometric analysis process involved the following key steps: (1) data collection and (2) keyword selection and search strategy, as already detailed in the search strategy section, (3) data cleaning and filtering, (4) bibliometric software utilisation, (5) network analysis, (6) quantitative analysis, (7) interpretation and insights, (8) validation and sensitivity analysis, (9) documentation and reporting and (10) discussion and implications.

2.2. Data Recording, Management, and Analyses

The screening of full-text articles was followed by assessing them for eligibility based on the inclusion and exclusion criteria explained earlier. In this systematic review, we engaged in robust data management and analysed the articles included. The articles/documents we assessed and found relevant were imported, organised, and stored in EndNote version 20.6 for Windows software developed by Clarivate Analytics, Philadelphia, PA, USA) [50]. To warrant the reliability and validity of the data and the findings, all the authors engaged in a thorough assessment of each included article, extracting critical information and details that involve the focus of the geographic location of the study, study design, CSA practices assessed, and pertinent findings related to the contribution of the CSA practices or climate adaptation strategies to food and income security of urban farmers. We stored and managed data on a laptop computer, used a narrative synthesis to analyse data, and followed ethical data management standards to uphold transparency and honesty. We systematically summarised the findings, drawing on significant themes and trends. In addition, we kept data on the Endnote software version 20.6 (Clarivate Analytics, Philadelphia, PA, United States) [50] and the search database’s built-in folder management (EBSCOhost) and search/saved list (Scopus) mechanisms to enhance transparency and reproducibility.

3. Results

3.1. Annual Scientific Production in Climate-Smart Agriculture Research in Sub-Sharan Africa from 2003 to 2023

Generally, the data in Figure 2 show that CSA research has grown steadily over the period under review, 2003 to 2023, demonstrating a modest increase. The number of articles substantially increased from 2003 to 2021, suggesting a significant increase in CSA interest and climate change awareness. Substantial growth in CSA research occurred in 2021/2, with the number of articles nearly increasing tenfold from 2003 (Figure 2). This growth trajectory implies increased research attention and efforts to implement sustainable farming practices amidst climate change challenges. Despite 2023 resulting in fewer articles (three), sustained interest in CSA research remains ongoing. Overall, the data suggest a positive trend and gradually expanding trajectory (dotted red line) in CSA research in SSA, a global recognition of the urgency and significance of developing resilient and sustainable agricultural solutions in response to global warming.

3.2. Most Globally Cited Documents in Climate-Smart Agriculture Research in Sub-Sharan Africa between 2003 and 2023

Based on the collected data, we identified the most globally cited documents/articles in the landscape of CSA research. Figure 3 displays the 10 most-cited articles from the analysed data. Various fundamental research studies emerge, as evidenced by substantial citation counts. Remarkably, the Makita et al. [53] article published in BMC Veterinary Research accounts for a significant impact, with 168 citations (Figure 3). Matthys et al. [54] in Tropical Medicine and International Health, Amoah et al. [55] (International Water Management Institute) (IWMI), Keraita et al. [56] (Journal of Risk Research), Lwasa et al. [57] (Urban climate), Keraita et al. [58] (Tropical Medicine & International Health), Keraita et al. [59] (Tropical Medicine & International Health), Gallaher et al. [60] (EcoHealth), McLees [61] (Journal of Modern African Studies), and Cadilhon et al. [62] (International Journal on Food System Dynamics) accrued 163, 100, 92 and 87, 83, 78, 50, 42, and 33 citations, respectively (Figure 3). The impact exhibited by the articles’ global citation implies the global influence that is necessary to promote a CSA and climate change adaptation agenda for achieving food and income security in SSA.

3.3. Country Scientific Production and Most Relevant Affiliations of Climate-Smart Agriculture Research Sub-Sharan Africa between 2003 and 2023

The scientific production of CSA research in a by-country analysis shows a diverse contribution landscape (

Table 1. Country scientific production and most relevant affiliations of climate-smart agriculture research Sub-Sharan Africa between 2003 and 2023.

Country	Number of Articles	Most Relevant Institution	Number of Articles
Nigeria	13	University of Ibadan	4
Ethiopia	11	Addis Ababa University	6
Kenya	10	University of Nairobi	4
Ghana	8	Kwame Nkrumah University of Science and Technology	3
South Africa	6	University of South Africa	3
United States	5	Michigan State University	4
Uganda	4	Makerere University	3
United Kingdom	3	University of Sheffield	3

Source: Data generated based on the Bibliometrix (Biblioshiny) package (RStudio Desktop) [49,52].

). The bibliometric analysis shows that, among the top countries, Nigeria leads, accounting for 13 articles. Nigeria, Kenya, Ghana, South Africa (SA), and Uganda have 11, 10, eight, six, and four articles, respectively (Table 1). The country’s scientific production of CSA and climate change adaptation research implies a regional effort regarding climate-resilient food systems and ecological considerations in the face of climate change. International institutions (United States of America (USA) (five articles) and the United Kingdom (UK) (three articles)) present a global discourse on CSA and climate change adaptation research in SSA (Table 1). Despite the international engagement in CSA and climate change adaptation research in SSA, it could be that some countries in SSA are inactive in this endeavour. Building an inclusive climate-smart framework in the region is paramount through a comprehensive urban regional CSA approach. We also embarked on the most relevant affiliations concerning the distribution of research articles on CSA and climate adaptation (Table 1). The bibliometric analysis shows the University of Addis Ababa in Ethiopia with the most (six articles) on CSA and climate change adaptation research, followed by the University of Ibadan (Nigeria) and the University of Nairobi (Kenya), each with four articles (Table 1). The following universities each produced three articles: Kwame Nkrumah University of Science and Technology (Ghana), Makerere University (Uganda), and University of South Africa (SA). Again, international institutions, including Michigan State University (USA) and the University of Sheffield (UK), contributed four and three articles, respectively (Table 1). The country’s scientific production bibliometric analysis demonstrates a global social mandate towards attaining sustainable food systems and empowering farmers’ economic development, especially in underdeveloped countries (Table 1).

3.4. Co-Occurrence and Interlinkages among Keywords

It is evident from the bibliometric analysis of the co-occurrence and keyword interlinkages that the terms “urban agriculture’’, “agriculture”, “food security”, and “land use” are central themes—occurring most frequently in the literature related to CSA in SSA (Figure 4). The bibliometric analysis of keyword occurrence shows that the countries (Ethiopia, Ghana, Kenya, and Nigeria) with the most frequent occurrence of these terms indicate the most-studied areas or geographic regions covering CSA and climate change adaptation (Figure 4). This analysis reveals the need to spread CSA and climate change adaptation research throughout SSA. The influence of urbanisation on agricultural land use is depicted by the “urbanization” and “land use” link. The dynamics of urbanisation are likely to influence urban farmers’ climate-smart choices in response to a rapidly changing climate. The keywords analysis shows a close relationship between the terms “urban farming” and “urban agriculture” and the term “food security” (Figure 4). With the food insecurity challenge becoming prominent in urban areas, exacerbated by heat islands’ intense heat from buildings and roads, UA is critical for enhancing food security in the face of climate change. Despite the numerous challenges posed by UA, the link between “urban agriculture”, “food security”, and “land use” suggests that small-scale urban farmers could leverage CSA practices to ensure food availability and, possibly, income prospects despite the fact that no link was discovered between “urban agriculture” and “income” in the analysis of the keywords from the bibliometric analysis. This disjuncture could suggest that more research is being done within the domain of food security than it is on livelihood and income. This finding could encourage more research in urban spaces and the dynamics of UA, climate change, and CSA and its nexus to income security. The keyword “humans” seems less connected than other terms (Figure 4), suggesting that the social attributes of UA, including labour, health, capacity building or urban community organizational dynamics, while acknowledged in the literature, remain understudied in terms of their implications for CSA or climate change adaptation towards resilient urban farming communities. The bibliometric keywords analysis necessitates a holistic policy framework for incorporating UA in urban planning, environmental management (land use), and socio-economic dynamics with the aim of enhancing food and income security.

3.5. The Implications of Climate-Smart Agriculture Practices on Food and Income Security of Urban Farmers

We identified and clustered several CSA practices or climate adaptation strategies from the review presented in

Table 2. The implications of climate-smart agricultural practices and adaptation strategies on food and income security.

Climate-Smart Agricultural Practices/Adaptation Strategies	Implications for Food Security	Implications for Income Security	Source/s
Efficient/improved water management—drought-tolerant seed varieties, improved water harvesting, drip irrigation	Enhances crop resilience and water use efficiency, ensuring stable yields	Stabilized yields and enhanced productivity improve farm income	[58,63,64]
Conservation agriculture and agroecology—mulching, cover cropping, crop rotation	Improves soil moisture retention and crop resilience, enhancing productivity	Increased crop yields lead to surplus produce for sale, improving income	[65,66]
Improved livestock management—improved feed to reduce methane emission, vaccination for commercial farms	Increases animal productivity and crop resilience, ensuring consistent production	Higher milk yields and quality improve farmers’ income from better market prices	[53,67]
Crop diversification and enhancement—underutilised species like Fonio and Bambara Groundnut, crop rotation	Contributes to food availability during hunger periods, enhances resilience	Economic potential for agro-processing, especially for women	[68,69,70]
Sustainable land use and management—the practice of UA on privately owned land, vertical greening systems	Reduces risks associated with UA pollution, enhances food availability	Creates employment and income generation opportunities from the sale of produce	[71,72,73]
Technological innovation for agroecological support—digital technology for agroecological support	Increases yield and diversifies diets in urban contexts, plus reduces pesticide use	Increase yield with less expensive inputs, opens new business opportunities	[66]
Livestock, financial and genetic resource management—low-emission practices, crossbred and indigenous dairy cows	Enhances dairy productivity and carbon sequestration, increasing milk availability	Affordable finance and improved productivity increase income for dairy farmers	[74,75,76]
Agricultural systems and practices—mixed farming/economy, urban and peri-urban pastoralism	Contributes to household food supplies and diet diversification	Offers additional income through the sale of surplus, diversifies income-sources	[77,78,79]
Ecosystem and environmental management—practices reducing risk of contamination, waste irrigation water for peri-urban-grown vegetables	Improves milk quality and safety, addresses health risks from contaminated water	Effective hygiene practices stabilize income through consistent acceptance of milk at the sales point	[59,80,81]
Community and social initiatives—collective action, membership in urban farmer groups	-	Association with membership groups correlates to urban farmers’ economic status	[62,82,83]
Organic farming and soil fertility management—organic farming practices facilitated by knowledge sharing	Improves soil health and increases yields, enhancing food security	Increases economic viability, leading to improved income security	[84,85,86]
Pest management and crop production—use of eco-friendly nets to reduce pesticide use, cleaner production practices	Enhances vegetable quality by reducing pesticide-related diseases	Reduces pesticide costs, improves vegetable yields and income from sales	[80,87]
Other strategies and enhancing adaptive capacity—urban community gardens, lobbying policy change	Ensures food availability through fresh vegetables, ensures yearly milk availability	Source of income and policy support provide fair milk prices	[62,83]

Source: Systematic review synthesis data.

and their contribution towards attaining food and income security. Some CSA practices or climate adaptation strategies may fall into multiple or more than one category/theme.

3.5.1. Efficient/Improved Water Management

Dube et al. [63] carried out a qualitative assessment of the peri-urban areas of Bulawayo, Zimbabwe that assessed how farmers perceived the effects of climate change and how peri-urban farmers adapted to climate change. Their findings demonstrate that drought-resistant crops and improved water harvesting (night irrigation and renting animal space with water sources) mitigate the negative impacts of climate change on crop yield and livestock productivity and enhance food availability and stability (Table 2). While these practices may provide alternative income streams, they increase the costs associated, with higher electricity bills for irrigation and increased labour costs for night-time watering, which reduces profit margins for peri-urban farmers (Table 2). Again, Keraita et al. [56] assessed the effectiveness of the cessation of irrigation before harvesting lettuce irrigated with wastewater to reduce microbial contamination in urban areas of Kumasi, Ghana. The findings illustrate that the cessation of irrigation before harvesting significantly reduced faecal contamination on lettuce during the dry season, although with risks of recontamination in the wet season, which improves the safety of vegetables, a critical aspect of urban food security (Table 2). However, they caution that cessation of irrigation before harvesting could reduce the yield of fresh lettuce weight per non-irrigated day in the dry season, which could impact urban farmers’ income.

On the contrary, reducing waste contamination would improve urban farmers’ income through improved market value and demand (Table 2). While improving water management and efficient water use through, for example, irrigation and innovation bolster food and income security of peri-urban farmers through increased yields and crop resilience, the insights could have implications on urban farmers concerning sustainable water management and innovation. Lessons from the findings could inform the use of, for example, innovative drip irrigation (which minimises water wastage), hydroponics (conserves water and provides a nutrient solution) instead of using contaminated wastewater, and vertical farming (maximises space while allowing precise/efficient water use) in compact urban environments. This innovation would likely enhance urban agricultural production and, thus, food and income security.

3.5.2. Conservation Agriculture and Agroecology

Chitakira and Ngcobo [65] assessed the extent of agricultural activities by smallholder crop farmers in the City of Tshwane Metropolitan Municipality in Gauteng Province of South Africa using mixed methods (qualitative and quantitative approaches) from 36 urban smallholder crop farmers. The study provides insights that CSA practices (cover crops, crop rotation, improved crop cultivars, and mulching) enhance soil moisture retention. Improving crop soil moisture retention would promote crop resilience, productivity, and yields, and, thus, food security (Table 2). An increase in crop yield implies surplus produce for the market, thus improving the income of urban small-scale farmers (Table 2).

3.5.3. Improved Livestock Management

Feyissa et al. [67] undertook a study that estimated the animal energy requirements for improved feed to reduce methane emission based on 2 500 cattle and 480 households from three dairy smallholder farming systems in the central highlands of Ethiopia. The findings suggest that improved feed could considerably increase animal productivity by reducing enteric methane emissions, enhancing the sustainability of dairy farming (Table 2). This CSA practice results in consistent milk production and, thus, food security. With higher milk yields and improved quality, efficient animal feeding will likely increase farmers’ income due to better market prices and reduced feed costs (Table 2). In consonance, Makita et al. [53] carried out a cross-sectional study in urban and peri-urban dairy farming systems in Kampala, Uganda, based on interviews and competitive enzyme-linked immunosorbent assay for Brucella abortus antibodies, and showed that vaccination of cattle on commercial large-scale farms with free-grazing reduces the prevalence of brucellosis in cattle substantially, lessening the risk of transmission to humans (Table 2). Therefore, improving dairy production (quality and safety) by urban and peri-urban farmers minimises brucellosis in cattle. As a result, it decreases the economic losses associated with abortion or calf death, potentially improving income security for urban dairy farmers through enhanced dairy productivity (Table 2).

3.5.4. Crop Diversification and Enhancement

Mbosso et al. [68] assessed the need for and opportunities allowed by improving the gluten-free, underutilised species Fonio and Bambara Groundnut and improving their value chains using a Rapid Market Appraisal method using surveys focusing on traders, producers, processors, and consumers in Mali. Their study advances the idea that underutilised crops are highly adaptable to local native environments and exhibit high nutritional value and early maturation. These attributes of underutilised crop species contribute significantly to food availability during the hunger period/s (Table 2). Again, underutilised crop species present an economic potential, especially for women involved in agro-processing (Table 2).

3.5.5. Sustainable Land Use and Management

Sustainable land management is essential for boosing local food production and safeguarding a sustainable and secure food supply as climate change and variability continue to affect urban areas, presenting difficulties of population growth and increased pressure on officials to import food. Mireri [71] determined the environmental and public health risks of cultivating crops on privately owned lands away from pollution sources in Kisumu City, Kenya, by sampling 24 edible crop tissues and 24 soil samples for heavy metal analysis. The study suggests that the practice of UA on privately owned land away from pollution sources exhibits low traces of heavy metals in crops (Table 2). The low levels of heavy metals in crops contribute to the city’s food supply, reducing risks associated with food pollution from UA. Again, the study offers insights that safe UA brings the prospect of creating employment and generating income by tapping into the urban-ready markets (the sale of produce within the city) (Table 2). Adegun et al. [72] carried out an exploratory and design study that used a crowdsourcing approach focusing on vertical greening systems (PET bottles, lattice, and HDPE pipe prototypes) for UA conducted in low-income urban settings in Lagos, Akure (Nigeria), and Dar es Salaam (Tanzania) and implementation in selected cities. The findings suggest that vertical greening systems improve food availability (vegetable needs) that can supplement food sources for low-income urban farmers (Table 2). Although there are immediate and indirect economic benefits of vertical greening systems for urban farmers, from a livelihood perspective, they may be difficult to adopt, limiting income security in the short run (Table 2).

3.5.6. Technological Innovation for Agroecological Support

Ebenso et al. [66] argue that a “One Health” approach to agriculture and environmental stewardship encompassing locally adapted crops, optimising urban spaces, minimising synthetic inputs use, increasing crop diversity and probiotics and postbiotics is critical for UA to increase food yields substantially (Table 2). The study also argues that locally adapted livestock breeds and digital technology for agroecological support enhance diversity (Table 2). Again, soilless techniques, agroecology, and digital decision-support systems improve yield, which diversifies diets for sustainable and nutritious diets for urban farmers (Table 2). Overall, a “One Health” approach increases yield with low-cost production and opens up new business ventures that will increase income for urban farmers (Table 2).

3.5.7. Livestock, Financial, and Genetic Resource Management

The inherently limited access to credit could pose financial and technical challenges for urban small-scale farmers for critical investment in CSA livestock and resources management. Odhong et al. [74] carried out a study that assessed the potential roles of public climate finance in enabling smallholder farmers in Kenya’s dairy sector (including improved livestock management and carbon sequestration in livestock systems) to adopt low-emission farming practices. The study utilised a mixed-method approach (primary and secondary data) using surveys conducted at farmer household, cooperative, and financial institution levels, including in rural and urban contexts. Insights from the study prove that low-emission farming practices enhance productivity and carbon sequestration in livestock systems through increased milk yields and stable milk supply, contributing to food security (Table 2). Again, access to affordable finance and improved productivity and efficiency represent financially profitable investments in low-emission farming practices that can increase income security for urban dairy farmers (Table 2). Duguma [75], through a survey method, examined crossbred and indigenous dairy cows for milk production (improved management strategies for shorter age at first service, age at first calving, calving interval, and lower number of services per conception) in selected towns of Jimma Zone, Ethiopia, involving 52 smallholder urban dairy cattle farmers. The study focused on milk yield, reproductive performance, and farmer preferences for dairy cattle traits. The study proves that better management potentially increases dairy cow performance and increased milk availability, thus contributing to food security (Table 2). Again, the study shows that improved dairy cow performance through crossbred cows could increase milk production for sale, enhancing income security for urban farmers (Table 2).

3.5.8. Agricultural Systems and Practices

Open-space suburban mixed (integrated) farming/economy and urban and peri-urban pastoralism are the practices considered under the agricultural systems and practices in this review. Owens [77] contends the dilemmas and prospects of the open-space suburban mixed farming/economy (cultivators) practising vegetable gardening, small-scale livestock rearing, and small businesses in Dar es Salaam, Tanzania. The study involved ethnographic research and surveys conducted in Kunduchi and Kibamba, Kinondoni district of Dar es Salaam, Tanzania. The study shows that UA contributes to household food supplies and diet diversification, reducing the burden of food purchase costs (Table 2). However, UA systems using contaminated water sources are of concern, as they may affect food quality and availability (Table 2). Again, the study considers UA’s suburban mixed farming/economy to offer additional income sources through the sale of surplus and diversified income portfolios (Table 2). Nonetheless, limited access to capital affects the sustainability and growth of suburban cultivators. Wafula et al. [78] investigated the factors determining urban and peri-urban pastoralism (trade in livestock, livestock manure, cattle milk; diversification into the trade of products such as beadwork, traditional medicine, wild honey, clubs, and leather products) in Nairobi City of Kenya. The study used a snowball sampling approach with semi-structured household questionnaires, focus group discussions, and key informant interviews across five sub-counties. Pastoralist migration within the urban areas confines provides access to broader urban markets for livestock and related products, which enhances food availability and diversity (Table 2). As a result, pastoralist migration provides diverse income-generating opportunities, including formal and informal employment through the trade of livestock and associated products, boosting the income of urban pastoralists (Table 2).

3.5.9. Ecosystem and Environmental Management

Ecosystem and environmental management practices that reduce contamination risk from waste irrigation water are critical for enhancing food and income security. Tigabu et al. [80] identified potential risk factors for milk contamination in urban and peri-urban areas in central Ethiopia. Data was collected through structured questionnaires from 433 farm owners, including interviews with 22 collection centre owners and microbiological analysis of 477 on-farm pooled milk samples plus 44 combined bulk milk samples. The study confirms that practices that reduce the risk of contamination (such as cleaner production practices—containers, detergent, Mastitis check, and efficient storage and distribution) reduce the risk of staphylococcus aureus contamination in milk production (Table 2). Again, hygienic practices improve milk quality and safety, directly impacting food security (safer dairy products for consumption). Besides food safety, effective hygiene practices reduce milk rejection rates, stabilising farmers’ income through consistent acceptance of milk at the sales point (Table 2). Abass et al. [81] investigated on-farm vegetable contamination and potential health risks of using waste irrigation water for 18 peri-urban grown vegetable farms (lettuce, spring onions, cabbage) in Kumasi, Ghana. They tested fresh vegetable samples for bacterial contamination using lettuce, spring onions, and cabbage randomly selected from the sampled farms. High levels of bacterial contamination (faecal coliforms, Escherichia coli) in vegetables pose health risks, undermining food safety and nutritional security for urban consumers (Table 2). Likewise, contamination issues affect marketability and produce prices and could negatively affect income security for urban farmers (Table 2). A related study by Keraita et al. [59] demonstrates the effectiveness of low-cost irrigation techniques (drip kits, furrow irrigation, and watering cans) reduce contamination of lettuce irrigated with contaminated water in urban areas. The study was conducted using a randomised block design in both dry and wet seasons in Ghana. Trials entailed lettuce, soil, poultry manure analysis, and water samples for microbial contamination. The review analysis proves that drip kits substantially reduce contamination of crops in contrast to other techniques (furrow irrigation and traditional watering cans) (Table 2). Drip kit technology minimises vegetable foliar injury, thus improving its attractiveness and marketability, resulting in higher income from quality produce (Table 2). Nonetheless, the drip kit method presents difficulty in weeding and is often clogged, which could affect the productivity and income of urban farmers.

3.5.10. Community and Social Initiatives

Balogun et al. [82] examined the poverty and welfare status of 272 randomly selected urban farming households in Kaduna state using structured questionnaires. Although the study did not explicitly focus on climate-smart agricultural practices or climate adaptation strategies, we juxtapose community and social initiatives discussed in the article as critical aspects for the adoption of CSA practices to mitigate climate change or contribute towards more resilient communities. The community and social initiatives inferred in this study include collective action and membership in urban farmer groups or organisations. While the findings reckon that a high prevalence of poverty among urban farming households implies potential challenges in food access and stability, collective action and farming experience associated with membership groups could positively correlate to improved urban farmers’ economic status (Table 2). The improved economic status is attainable by sharing resources and using collective bargaining power in markets. Urban agriculture community and social initiatives vary from community gardens, composting programmes (for waste recycling and providing nutrient-rich compost), cooperatives, educational platforms, markets, supported agriculture programmes, urban food festivals, and other urban community-led initiatives, including youth engagement programmes. The urban community initiatives could contribute to conserving biodiversity, urban aesthetics, a new generation of environmentally conscious urban farmers, and sustained food production and supply, including income generation.

3.5.11. Organic Farming and Soil Fertility Management

Adebiyi and Olabisi [84] used a system dynamics participatory causal loop diagramming (mapping) and feedback mechanisms (workshops held with organic farmers) in Nigeria’s rural and urban settings driving the adoption of organic farming in rural and urban Nigeria to map the underlying causal factors and drivers of the adoption of organic agriculture. From their findings, it is deduced that organic farming enhances yield due to improved soil health and less heavy mental usage (Table 2). There is increasing consumer demand for organic products that come with a willingness to pay a price premium. This demand suggests improved income from organic products for urban farmers (Table 2).

3.5.12. Pest Management and Crop Production

Vidogbéna et al. [87] surveyed 214 small-scale peri-urban vegetable farmers in Benin in West Africa, to explore perceptions of different attributes of eco-friendly nets for vegetable production to reduce pesticide use. The survey shows eco-friendly nets enhance vegetable quality by reducing pesticide-related diseases and improving food security (Table 2). Additionally, eco-friendly nets reduce pesticide costs, improve vegetable yields, and thus improve farmers’ income from vegetable sales (Table 2). However, the labour intensiveness of eco-friendly nets on large plots could offset income.

3.5.13. Other Strategies and Enhancing Adaptive Capacity

Other climate-smart practices and enhancing adaptive capacity identified in this review encompass urban community gardens and lobbying for policy changes to support dairy farming. Modibedi et al. [83] conducted a study in Emfuleni Local Municipality in Gauteng Province of South Africa, using a quantitative approach and survey design to determine and assess urban community gardens’ contribution to food availability. The study collected data from 254 participants through semi-structured survey questionnaires. Their results found that urban community gardens growing vegetables, with emphasis on sustainable production practices (irrigation, greenhouses, and drought-resistant cultivars), ensure food availability through the provision of fresh vegetables all year round, reducing reliance on external food sources and providing a diverse and nutritious diet (Table 2). Correspondingly, community gardens are an essential source of income for urban farmers, lowering the cost of food expenditures and redirecting funds to other needs (Table 2). Cadilhon et al. [62] case study in the peri-urban and rural areas of Tanzania’s Northeastern Tanga region looked at the institutional innovations concerning the dairy industry, as well as its management structure and challenges. Data was collected through participatory approaches (meetings involving stakeholders from various sectors of the dairy industry, including government, private sector, and non-governmental organisations) focusing on aspects that include lobbying for policy changes to support dairy farming (reduction of value-added tax on dairy inputs and products), enhancing unity among dairy stakeholders for effective lobbying and advocacy, promoting equitable and competitive milk supply chains. The case study revealed that policy support and a more organised dairy value chain ensure the availability of milk throughout the year, even during dry seasons, potentially improving food security (Table 2). Furthermore, policy support and a more organised dairy value chain provide fair milk prices and reduce production costs through tax exemptions, leading to increased profitability and sustainability of dairy farming and investment into the sector that enhances the income security for urban dairy farmers (Table 2).

4. Discussion

This review sought to synthesise and analyse the implications of CSA practices or climate adaptation strategies in UA; specifically, (1) we employed a bibliometric analysis using unit publications, citations, and keyword occurrences to illustrate some key trends and identify knowledge gaps, and explored the implications of CSA practices to (2) urban farmers’ food and income security of small-scale urban farmers. The review offers critical insights into CSA’s influence on UA and food and income security in SSA. Population growth and urbanisation influences are exerting pressure on urban areas due to increased food demand and poverty levels. The current systematic review unveiled various CSA and climate change adaptations and their implications for food and income security of urban farmers.

The review shows that efficient water management, conservation agriculture, improved livestock management, and innovative strategies are critical in mitigating the negative consequences of climate change and enhancing sustainability in UA. Xie et al. [88] underpin the essence of efficiency in water use in UA under climate change constraints. Scaling up CSA practices is essential for improving sustained food production under the climate-induced water stresses that urban farmers contend with. Effective water use, therefore, promotes water-saving innovations and reduces food contamination risks for small-scale urban farmers. For urban farmers who use wastewater to irrigate crops, drip irrigation and ceasing irrigation before harvest could be viable strategies. This strategy can mitigate drought impacts and ensure food safety. Therefore, effective water management techniques are essential for water-smart crop farming, as advocated by Frimpong et al. [89]. The review demonstrates that drought-resistant crop cultivars, innovation in water management techniques, and night irrigation practices are vital in mitigating the negative reparations of climate change on crop yield and livestock productivity. Improved yield and productivity will ensure stability in food production and, thus, availability in urban areas. Again, the benefits of efficient water management techniques in UA could aid in bolstering the income of small-scale urban farmers through sustained production and lower water use costs. In addition, with improved production, urban farmers could benefit from information-sharing platforms and access lucrative markets. On the contrary, urban farmers should also recognise economic trade-offs, for example, increased bills for electricity for irrigation and associated labour costs for night-time watering. These costs could lower the viability of UA, especially during the global energy crisis [90].

Blanchy et al. [91] offer insights into enhancing soil moisture retention and crop resilience through conservation agriculture and agroecological practices (cover crops, crop rotation and mulching). Improving soil health and crop resilience under climatic-related challenges could help urban farmers improve productivity and, subsequently, food security. Beyond food security, urban farmers could have a surplus for the market that will provide extra income. Concerning livestock management, improved feed and vaccination programmes enhance animal productivity and reduce animal diseases. Improved livestock management practices certify and guarantee reliable production, which is likely to strengthen urban farmers’ food and income security through, for example, higher milk yields and quality dairy [92].

Diversifying livelihood portfolios, for example, through crop diversification, including cultivating underutilised crops and engaging in small businesses, could be a climate change coping strategy for urban farmers. Diversification provides options for accessing food in times of hunger and opens up agribusiness opportunities, particularly for women in agro-processing [93]. Diversifying agricultural production coupled with other economic activities by urban farmers in the face of climate-related shocks could also be essential, for example, integrating underutilised crops, agro-processing, and farm-related merchandise. Owolodun and Merten [94] mention that commodification and commercialisation by farmers provide prospects for cash income, which could improve food security. Underutilised crops are, therefore, a climate-resilient option that is also cost-effective for mitigating the effects of climate change. The food insecurity predicament brought about by climate change that is parallel to the exponential rise in urban population could be lessened by incorporating underutilised crops within sustainable farming systems. Goufa et al. [95] allude to the fact that underutilised crops are a significant CSA practice because of their increased resilience to biotic-abiotic environments, protein richness, adaptability, and improved seed preservation.

The review shows the importance of integrated crop and livestock systems in enhancing the resilience of urban farmers. Sustainable agriculture, alongside bolstering production, could be achieved through mixed crop-livestock systems in the face of climate change and variability. Cruz Colazo et al. [96] state that enhancing soil organic carbon is better achieved in integrated crop-livestock systems than in continuous cropping systems. Therefore, integrated crop-livestock systems present a low-cost climate change adaptation strategy for UA that can increase resilience and productivity. Harnessing low-cost systems by urban farmers is pertinent to the transition towards agroecological and environmentally friendly practices. Agroecological and environmentally friendly practices promote sustainable land use management practices that eliminate environmental hazards, thus enhancing food availability [97], and offer employment and income-generation opportunities. Overall, sustainable agriculture enhances the likelihood of lower yield failure under climate and weather-related stresses and improves urban farmers’ economic security.

Again, technological innovations for agroecological support emphasise environmental stewardship, such as soilless techniques, digital decision-support systems, and ecological options that can increase yield, diversify diets, and open new business ventures for urban farmers [98]. This thinking calls for CSA practices that optimise urban spaces while minimising synthetic inputs. Urban farmers could take advantage of technological innovations for agroecology, such as digital innovations, to manage resources efficiently. Their adoption will, however, depend on access to essential financial and educational attributes. Indeed, Jellason et al. [99] point out that there is a gap in knowledge, skills, finance, and infrastructure when it comes to adopting technological CSA practices successfully, particularly for poor urban farmers. Financial and genetic resource management improves productivity and carbon sequestration in livestock systems [100,101]. For urban dairy farmers to invest in lucrative low-emission farming practices would require affordable finance options. Therefore, digital innovations and financial support are paramount for ensuring viable agribusiness-driven production, plus promoting access to markets. Enhanced market access is synonymous with profitable agricultural enterprises and, thus, income stability for urban farmers.

The review analysis provides the perspective that urban farmers could enhance food and income stability through organic farming. Organic farming improves soil fertility health, which is critical for sustainable agriculture. The perspective agrees with Selvan et al. [102] that organic farming is substantially relevant to promoting food and nutrition security and sustaining livelihoods. Organic-based farming enhances soil fertility, which leads to improved productivity. Again, enhanced soil fertility eliminates production costs such as fertiliser, thus enhancing urban farmers’ income and economic well-being. Brzozowski and Mazourek [103] show that the value of certified organic farming outperforms that of non-certified farms concerning economic resilience, environmental integrity, and worker support, likely to contribute to improved income security. Although farmers in some SADC countries have implemented organic farming, the prevalence of non-certified organic farming and adoption barriers, particularly by small-scale farmers, must be overcome through coordinated efforts involving different stakeholders.

Some climate change risks will require effective pest management. The current review pinpoints the significance of pest management in fostering resilience for stable food production. The review suggests eco-friendly nets as a vital CSA practice to manage pests and scale up agricultural resilience for UA, ensuring increased productivity and food security for urban farmers. As pest and disease management is a significant concern under climate change for achieving sustainable agriculture, Bouri et al. [104] emphasise that farmers must make informed economic decisions regarding selecting the right pest management technique/s for mitigation and adaptation to climate change. Despite the prospects for enhancing farm income from improved pest management, Gugissa et al. [105] alerts against the implementation barriers, for example, lack of input and output markets access and inadequate animal health services, would require concerted, collaborative efforts from all the actors interested in agricultural development under climate change.

Substantial CSA uptake and climate adaptation in UA are also driven by community and social factors that encompass collective action and organisational membership. Collective action and organisational membership improve access to, for example, knowledge sharing, extension and advisory services, sharing of resources, and financial support in urban areas to marginalised groups like women and youth, which could be symbolic of enhancing food security under increasing climate change farming challenges. Mosso et al. [106] caution that, in as much as CSA constitutes a hopeful approach to reducing vulnerability, boosting adaptation capacity, and improving climate change resilience, addressing social aspects such as gender and youth dynamics is critical to reaching full CSA potential and mitigating the detrimental effects of climate change on agricultural production and food security. Again, policy advocacy, for example, for urban dairy farming, is critical to quality, food availability, and avenues for income generation. Notwithstanding the advantages of CSA for UA, they could be associated with adaptability challenges and implementation costs that small-scale urban farmers should not overlook.

Despite the prospects for bolstering urban farmers’ food and income offerd by CSA practices, this review acknowledges some critical challenges and trade-offs for consideration. Despite, for example, the higher revenue prospects from CSA adoption, it is essential to note that some CSA strategies come at the cost of increased revenue variance, making urban farmers more vulnerable to yield and price fluctuations. Also, obstacles posed by incremental adaptation strategies, such as rising farm input costs and limited access to infrastructure such as irrigation technology, necessitating the need to address these limitations, given the potential to increase income for urban farmers, should not be understated. The rising trend in innovative irrigated farming systems underpins the significance of water efficiency use in irrigation technology for climate adaptation. However, disproportions in CSA adoption necessitate interventions and policies to advance CSA technologies and understand land use dynamics [107]. The review underpins the essence of urban community-based efforts. Indeed, Abdillah et al. [108] accentuate the importance of a human development perspective in land use management policies, advancing equitable access, efficiency, empowerment, and sustainability for urban low-income residents. It is, therefore, imperative to introduce, for example, gender-equitable access to resources, support, and education, particularly for urban female farmers, to foster economic resilience in the face of climate change. The findings, again, echo the significance of policy and the effectiveness of tailored actions incorporating, for example, market-based mechanisms and spatial heterogeneity as critical for successful policy implementation for agricultural development resilience [109].

5. Conclusions

This systematic review first identified knowledge gaps concerning CSA practices or climate adaptation in SSA for small-scale UA through a bibliometric analysis of unit publications, citations, and co-occurrence and interlinkages among keywords. Although the bibliometric analysis shows a growing research trend over the past 20 years, there is a need for a more nuanced holistic comprehension of CSA practices and climate change adaptation within urban areas in SSA. The review analysis suggests collaborative research in the region that focuses on the unique challenges faced by small-scale urban farmers, including urban socio-economic dynamics, policy mechanisms, regulatory frameworks, and innovation to optimise the CSA and climate change adaptation that is critical to enhancing food and income security. Attention to this significant research gap could advance CSA and climate change adaptation, which is likely to foster UA resilience against climate change in SSA and subsequently contribute to the sustainability of urban food systems amidst the climate change threat.

This systematic review also delved into the implications of CSA and climate change adaptation for small-scale urban farmers’ food and income security, drawing from relevant research in SSA over the past 20 years. The review depicts the urgency of adopting CSA practices or climate change adaptation strategies to attain food and income security by small-scale urban farmers. Innovative CSA practices and climate change adaptation strategies that include embracing digital technology for agroecological solutions, crop diversification, and effective water management are imperative to foster urban farmers’ resilience against climate change that will bring about sustainable food production and economic gains. The inherent resource constraints faced by urban farmers necessitate resource optimisation for CSA to enhance food and income security. Leveraging small-scale and low-cost but innovative CSA by urban farmers, such as aquaponics and vertical farming, is critical. Land and space constraints limit crop rotation and livestock management CSA practices. This resource limitation will require leveraging technology and navigating urban regulatory and policy frameworks integrated into innovative livestock and crop management practices. Innovative techniques like fish tank farming alongside plant cultivation, mobile farms, container farming, urban community gardens, edible landscaping, and smart greenhouses could foster collective efforts to promote urban aesthetics while offering functional food and income security. The growing trend of food insecurity and poverty levels in urban areas calls for immediate transformation to support UA, minimising trade-offs and eliminating barriers and challenges while enacting appropriate policies and support mechanisms to promote the uptake and utilisation of CSA to promote climate resilience. Overall, the CSA approaches identified and discussed in this review could offer a preface towards a holistic approach to enhancing UA and addressing the challenges of space and resource limitations while contributing to reducing the carbon footprint. We call for continued focused research to tackle CSA uptake by small-scale urban farmers, more so in regions vulnerable to climate-related disruptions, to unveil the complex dynamics and their influence on UA implications on food and income security. Future research could focus on nuanced economic and environmental cost-benefit analysis to guarantee widespread adoption and effectiveness in combating CSA adaptation challenges posed by climate change in UA.