Soil is getting saltier – but African farmers are standing strong

Few plants thrive in soil with high levels of salt. Most crops start to wilt, even if they are watered well. Their growth is weak, their leaves drop and their yield is low. Alarmingly, an estimated 10 per cent of cropland worldwide is salt-affected, and this figure is rising.

While irrigation is a gamechanger for agriculture, its reckless use can lead to the overexploitation of aquifers, which can in turn make the groundwater salty. When small-scale farmers use this groundwater for further irrigation, the salts may be deposited in the soil. Improperly drained soils can also accumulate salts.

To make matters worse, rising sea levels carry salt to soils and aquifers, worsening droughts prevent it from being washed away and increased heat leads to more groundwater being extracted for irrigation and other uses.

In the countries most affected by cropland salinity, FAO has estimated up to 72 per cent losses for rice, 68 per cent for beans and 37 per cent for maize. This has severe implications for food security, especially in communities already experiencing fragility.

That’s why RESADE, a recently completed project funded by IFAD and implemented by the International Center for Biosaline Agriculture, aimed to build resilience to salinity among small-scale farmers in western and southern Africa. Working with agricultural research institutes in seven countries, the project introduced innovative approaches to increase agricultural productivity, build food security and boost economic returns to enable farmers to leave poverty behind.

Through RESADE-supported farmer field schools across western and southern Africa, farmers have learned to use low-cost, locally produced units that heat farm waste in a low-oxygen environment for up to a day. This creates biochar, a stable form of carbon that is then applied to the soil to condition it and protect it from degradation.

Enriching soil with biochar not only sequesters carbon, but also helps the soil retain water and nutrients and makes crops more tolerant to irrigation with saline water. In The Gambia, biochar increased the germination rate of sorghum irrigated with slightly saline water by 25 per cent and pearl millet by 62.5 per cent.

Couscous is part of the daily diet for many Togolese, but the rising cost of wheat imports is putting this beloved staple out of reach for many households. That’s why, with support from RESADE, farmers have learned to make couscous from sorghum, building their food security and reducing their exposure to market fluctuations.

Sorghum is a new crop for farmers in Atti-Apédokoè in southwestern Togo, but they can already see the benefits. Longer periods of drought and higher temperatures have dramatically reduced maize and wheat yields.

By contrast, sorghum is a tough cereal that needs little water and can withstand heat. It's also more salt-tolerant than maize. It can be used for fodder, fermented to make beer or ground into flour. As an ingredient to make couscous, it fits easily into local diets.

Sorghum is one of several nutritious, drought-tolerant crops that RESADE introduced across the project countries. The project has established six community-based seed banks so that farmers can access these new varieties and learn how to use them.

Emefa, a farmer who attended the session on making sorghum couscous, is looking forward to planting the crop in her field. “After making couscous from it, we see that it can be a good alternative to wheat and can help us increase our family income,” she says.

RESADE also worked with communities to explore new ways of processing the foods they grow, adding value to them, marketing them effectively and increasing income.

One of these foods is lerotse, a native watermelon of Botswana, which drinks up water when it rains, then fruits and flowers when the weather is dry. But as droughts become more frequent, many farmers have a surplus of lerotse and often let them rot in the fields.

Thanks to RESADE, lerotse is now providing a valuable income stream for farmers like Masego in salt-affected areas. During a RESADE training, she discovered that lerotse is more than just a cooking melon – it can also be used to make a tasty juice. She learned how to obtain food production licences and nutritional analyses, then registered her company, Makaba Lerotse Juice Product.

Masego’s small business now sells juice to event organizers, earning up to 10,250 pula (US$750) a month. She has hired two assistants to keep up with demand, and she is optimistic about the future of her business. “I believe that Botswana will plant more melons now that a new market is available,” she says. “This will also ensure sustainability for my business as raw materials will be readily available.”

As small-scale farmers in Sub-Saharan Africa sustainably boost food production, it’s crucial to ensure they are equipped with innovative approaches that protect their businesses against challenges like salinity and changing weather patterns. In this way, they can build resilience to shocks and ensure food security for themselves and their communities across the continent.

To learn more about RESADE, visit the Agricultural Research for Development (AR4D) page.