Greywater, greenhouses increase food production in Tunisia

Jonah Engle

In North Africa and the Middle East, rapid urban expansion is stressing local water sources and food production. Research shows how cities and agriculture can grow together.

Research focus

To address how climate change and urban expansion in peri-urban Tunis threaten small-scale farmers.

The challenge

In the town of Soukra, Tunisia, hundreds of poor families feed themselves and earn a small living from agriculture. In recent years, however, a number of factors have threatened their livelihood.

As the country has rapidly urbanized, the capital city, Tunis, has expanded, encroaching on farms and driving land speculation. New land uses, which are incompatible with growing food, are sprouting up next to farmers’ fields. Since the 1990s, the amount of arable land in Soukra (only 6 km away from Tunis) has decreased by nearly 30%. “It’s a problem we’re seeing around most cities throughout North Africa and the Middle East,” says Moez Bouraoui of the Tunisian NGO Club UNESCO/ALECSO and president of the Urban Agriculture Association of the Middle East and North Africa.

Farmers in Soukra face significant water stresses as well. Climate change has altered rainfall patterns causing droughts and floods. In times of water scarcity, farmers draw increasingly from wells. This has disrupted the water table as the large saltwater lagoon bordering the town has begun seeping into groundwater. As a result, the earth is waterlogged in some places; in others it is becoming too salty to grow healthy crops.

Farmers are made more vulnerable because urban agriculture has not been protected in local land use planning and their interests are not represented in municipal government.

With funding from Canada’s International Development Research Centre, Club UNESCO/ALESCO set out to find comprehensive ways to mitigate the environmental threats farmers face, while giving them the tools to lift themselves out of poverty.

Akiça Bahri
Suspended cultivation vastly increases yields and boosts soil health.

The research

With the help of local institutions, researchers undertook a comprehensive year-long study of Soukra’s environmental, social, and political conditions. This led to the development of a two-fold plan. First, new, environmentally sustainable sources of water for irrigation would be deployed to increase agricultural production. Then, greater yields would help create small businesses for the farmers who had largely been growing subsistence crops.

Technicians built greenhouses, which help conserve water, protect crops, and allow for more intensive farming. They then installed basins on rooftops adjacent to farmers’ land to store rainwater and deliver it to crops.

Greywater – the water used for household bathing and cleaning – was also captured, filtered, and used for irrigation. Following Tunisia’s strict wastewater use regulation, it was used to grow flowers, a lucrative cash crop. On waterlogged soil, farmers brought in extra earth and planted olive trees, which can survive in these conditions. Greywater irrigates the roots of these trees.

All told, farmers are growing 10 kinds of fruit and vegetables. The greenhouses have extended the growing season and increased incomes as farmers can get much higher prices for produce, such as tomatoes, when they are out of season.

A greenhouse produces six tons of tomatoes worth around CA$4,600. Farmers’ proximity to market allows them to skip wholesalers and sell directly to consumers, increasing their profits. The farmers, who were once among the poorest in Soukra, are enjoying better lives. One mother paid for her daughter’s wedding, others have expanded their homes. “One of the most tangible signs of success,” says project coordinator Moez Bouraoui, “is that some farmers are reinvesting their profits into building more greenhouses.”

Akiça Bahri
Using rainwater and micro-irrigation maximizes a scarce resource in an arid climate.

Expected impact

In the best tradition of applied research, farmers and researchers have continually refined production. Greenhouses usually have to be moved every 5 years to avoid soil depletion. Because space constraints make this impossible in Soukra, farmers have been experimenting with lucrative crops grown in containers above the soil, allowing the ground to lie fallow. These crops include strawberries and lettuces. They also include snails, which provide fertilizer.

Researchers have pioneered a new way to catch rainwater from the greenhouses’ rounded roofs. Gutters, built into the greenhouses’ support structure, channel the rain into storage tanks, making the greenhouses 60% water sufficient.

The research team has worked closely with the city government to help it recognize the ecological and economic value of urban agriculture and encourage it to include small-scale farming in land use planning. Last year, the farmers formed a cooperative, which gives them a stronger voice in local decision-making. The cooperative is taking over management of the research, which will ensure its long-term sustainability.

This model of urban agriculture and the many technical innovations the research has produced are now being disseminated throughout Tunisia and the region by the mass media as well as through scholarly articles, workshops, and conferences. The solutions pioneered in Soukra provide excellent examples for countries in the region coping with water scarcity and climate change.

Jonah Engle is a Montréal-based writer.

Photo (top): Akiça Bahri
Growing commercial crops in greenhouses has lifted farming families out of poverty.

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