What is the social and/or ecological challenge?
Sub-Saharan Africa has recently experienced below-average rainfall due to climate change, resulting in below-average food supplies. The Zambian government has prioritised the development of ”sustainable land use systems to enhance agricultural production and ensure food security under the changing climate” (National Climate Change Response Strategy, 2010). As traditional farming methods depend on reliable rainfall, other methods are needed to avert famine. In Sub-Saharan Africa nearly 70% of the water taken from rivers and groundwater goes into agricultural irrigation. At the same time, demand for protein and fresh produce is growing as the population increases, from 1.2bn today to a forecasted 2.5bn by 2050 (United Nations). Zambian farmers are unable to consistently deliver fresh high-quality produce due to poor irrigation, pests and limited access to adequate storage. Despite local sourcing targets of 70%, Zambian supermarkets regularly import fresh produce from South Africa. However, long-distance transport is expensive and reduces food quality. While fish is an important source of protein for most Zambians, annual capture fisheries output per person declined from 11.4kg in the 1970s to 6.4kg in 2003. The estimated market for high-quality horticulture in Zambia is USD 29 million, with demand growing in step with GDP (currently 6%).
The social entrepreneurial approach
Aquaponics (AP) can be used for horticulture as well as aquaculture. It can deliver high-quality crops year-round as well as better yields than field-based farming. In addition, it can use as much as 50% less water as drip irrigation systems and is independent of rainfall. A single commercial AP system covers half a hectare of land and produces 570kg fish and 4,600 heads of lettuce per week. The technique brings production close to markets and eliminates water loss to soil, making it suitable for arid regions and an ideal alternative to traditional farming.
Clearwater Farms will use AP for synergistic production of horticulture and fish. The enterprise targets smallholders or cooperatives, offering to help them generate income and access local markets. Its end customers will be supermarkets (20% of the Zambian horticulture market), hotels and restaurants. There will also be a return for investors who finance the development of the enterprise. Target groups will be reached through networks of smallholder farmers, including NGOs and farming associations. The strategy is first to verify the AP approach in the market and the sales channels to end customers. Clearwater Farms will provide ongoing training and mentoring for AP adopters.
Goals and expected impact
This initiative will enable smallholder farmers and cooperatives to consistently supply high-quality fish and horticulture to local premium markets. It will also support the creation of cooperatives in which several subsistence farmers can operate an AP system together. The impact on participating farmers will be higher revenues, improved skills and more income to pay for education, clothing and transport, which will increase employment in the community generally. The AP system will halve water usage relative to drip irrigation best practice and slash the supply chain miles travelled. The first system tested under this initiative is expected to produce 240'000 lettuce and 30 tonnes of fish per year and save 13 million litres of water. It will employ 20 people and bring more income into local communities.