Producing more food with less water

THE CHALLENGE

Sub-Saharan Africa has recently experienced below-average rainfall due to climate change, resulting in below-average food supplies. 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 rising within Sub-Saharan Africa’s population, which the United Nations expects to increase from 1.2 billion today to 2.5 billion by 2050. As traditional farming methods depend on reliable rainfall, other approaches are needed to avert famine.

Farmers in Zambia are unable to consistently deliver fresh high-quality produce due to poor irrigation, pests and limited access to adequate storage. Moreover, while fish is an important source of protein for most Zambians, annual capture fisheries’ output per person declined from 11.4 kg in the 1970s to 6.4 kg in 2003.

THE APPROACH

Applicable in horticulture as well as aquaculture, aquaponics (AP) can deliver high-quality crops year-round as well as better yields than field-based farming. It also uses as much as 50% less water as drip irrigation systems and is independent of rainfall. The technique brings production close to markets and eliminates water loss to soil, making it an ideal alternative to traditional farming in arid regions.

Clearwater Farms uses aquaponics for synergistic production of horticulture and fish. The enterprise buys from smallholders or cooperatives, helping them generate income and access local markets, and sells to supermarkets, hotels and restaurants. It also offers a return for investors who finance the development of the enterprise. The strategy of Clearwater Farms in this project is first to verify the approach in the Zambian market and the soundness of its sales channels to end customers. It will then 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 by supporting the creation of cooperatives in which several subsistence farmers can operate an AP system together.

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, in Lusaka, Zambia, is expected to produce 240 000 heads of 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.