Sustainable Urban Farming in Sub-Saharan Africa: A Review of a Coupled Single-Loop Aquaponics System in Nigeria

Abstract

Countries in West Africa are adversely affected by climate change (erratic rainfall and rising temperature) resulting in floods, desertification, drought and sea level rise. These events are anticipated to have negative impacts on agricultural development on the continent, ultimately, contributing to food insecurity and environmental degradation. This implies that the production capacity of agrarian communities is unable to meet the food demand of the growing urban population. Can sustainable and innovative urban farming technology such as aquaponics achieve food security as well as sustainable development in countries vulnerable to climate change? This study uses inferential statistic to examine the plant growth performance in micro-scale aquaponics and specific growth rate per day (SGR) for the fish growth performance vis-à-vis conventional urban farming production. A quantitative analysis use to examine the barriers to adoption based on survey of (five) urban aquaculture practitioners in Lagos, Nigeria. Literature review was use to assess the economic feasibility of a small-scale aquaponics system in developing countries based on Net-Discounted Benefit-Cost Rate (DBCR). The results suggest that aquaponics can improve food security through fish and vegetable production and it is likely that urban farming practitioners will adopt the technology if support mechanism are in place. Aquaponics systems present a novel opportunity to promote environmental conservation as well as sustainable food production and consumption in urban areas in Western Africa if adequate financial credit and knowledge transfer is provided.

Technology-Business-Management of Recirculating Aquaculture System (RAS) for Sustainable Urban Farming in Sub-Saharan Africa: A Review of Challenges and Opportunities

“…The grow out weight of the African Catfish at this stocking density at the end of the four months period was above 500 grams and a length above 40 cm. Benjamin et al [6,7] also found that after four months a length of 40 cm as well as a weight of over 500 grams was achievable in African Catfish. Brummet [10] argue that for aquaculture to develop in Africa and provide diverse benefits to society, a business approach that focuses on small and medium scale enterprises must be adopted.…”

“…A number of factors ranging from high fertility rates to rural-urban migration drives population growth and urbanization [1,41]. This implies that there will be a substantial increase in the demand for animal sourced foods (ASF), specifically fish protein, in cities and towns, which (rural) producers will be unable to meet [7]. Furthermore, prospective (rural) fish farmers, often young and agile, seek greener pastures in cities abandoning farming altogether.…”

“…Thus, to improve urban FNS and reduce the pressure on the environment, Davies et al [14] and FAO [18] calls for the introduction of novel circular agri-food technologies and practices in the urban food systems, which simultaneously generate income through profitable businesses. A number of studies [6,7,9,37] have also emphasized the need for innovative urban farming technologies that require limited resources (i.e., land and water). Examples of such innovative urban farming technologies include recirculating aquaculture systems (RAS).…”

Enhancing community well-being in African drylands through technology-based solutions in the water–energy–food–ecosystems nexus

“…Aquaponics, producing at the same time vegetables and high nutrition value fishes, are considered as sustainable and intensive food production systems. 98,[107][108][109] During recent years, aquaponics technology features and design have evolved to enable its rapid transition to industrialscale production in many nations worldwide, but its uptake in Africa remains relatively limited. Despite the potential advantages of aquaponics in Africa, barriers to its widespread adoption include a lack of technical knowledge, inadequate infrastructure, and lack of funding.…”

“…The electrical consumption is also considered as the second most cost-intensive component category in aquaponic systems as it covers the requirements of heating and cooling systems as well as operation components (pumps, fans, inverters…). 109,112 For this reason and in order to reduce water heating energy expenses, it is recommended to match the choice of the plants and/or the fishes with the local environmental conditions, particularly ambient air temperature, and to use passive techniques of water heating either directly by a residual heat or by solar energy or by installing soilless units inside greenhouses. 98,102,104,113 Alternatively, fossil fuel electricity can be substituted with photovoltaic electricity to feed aquaponic and hydroponic systems, which improves the energy efficiency of these WEFE nexus solutions.…”