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Fighting climate change

May 18, 2012

Drought, poor soil and erratic rainy seasons are problems that affect African farmers daily. But scientists are hoping to change that, with the help of cassava roots that seem able to withstand climate change.

cassava roots showing the brown exterior and grey interior
Image: picture-alliance/Arco Images

Cassava root, also known as manioc, is dark brown on the outside while the inside is grey or reddish. Some varieties taste sweet while others are bitter. They are mostly grown in South America, Asia and Africa. Front runners are farmers in Nigeria. One of them is Abubakar Sadiq Alaji Takingari. "Cassava is a product that can withstand heat and drought and needs little or no fertilizer, " he says. In addition, cassava itself enriches the soil with nutrients. In the current season "we did not need additional fertilizer, because we used our former cassava fields to grow millet and corn. The cassava roots and leaves left on on the ground acted as fertilizer for millet and corn," Takingari says.

A 'Rambo root'

Climate researchers have now also become aware of the tuber. They have tested how cassava responds to climate change, looking ahead to the year 2030 when temperatures in sub-Saharan Africa are predicted to have increased by two degrees Celsius. "We have found out that cassava is resilient and can cope with almost all climate conditions. That's why we call it a Rambo root," says Andy Jarvis, a climatologist at the International Center for Tropical Agriculture in Colombia, referring to the tough protagonist of the action film series.

A closeup of a woman sitting with a sack full of flour
Cassava flour and beans are used as staple foods in most African countriesImage: Dagmar Wittek

The researchers are also testing how other staple foods can adapt to climate change. Compared to corn, potatoes, beans, bananas and millet, cassava is the most adaptable. "The big advantage is that cassava can survive even very long periods of drought," Jarvis said. " It slows down its activity and waits until the next rainy season." This drought tolerance stems from the plant's origins. Cassava originally comes from a very hot and dry region of South America and was taken to Africa by the Portuguese in the 16th century. Today, it provides food for more than 500 million people around the world every day. In Africa cassava it has become the second largest source of energy.

Susceptible to pest and diseases

But this miracle root is also dangerous. Like any other tuber, cassava can release toxic substances such as hydrocyanic acid. It must therefore be properly prepared and cooked before consumption. Although cassava is rich in starch and calories, it is unhealthy to have a diet based mainly on this root. Moreover, the plant is susceptible to certain pests and diseases.

Cassava roots
In a bid to promote cassava, the Nigerian president has promised to eat it every day while he is in powerImage: DW

Scientists hope that their climate-related findings will spur further research into cassava. The tuber could be developed, for instance, by crossing it with other plant species. "Researchers are also trying to increase the nutrient content in cassava roots, to increase their nourishment potential," says Andy Jarvis.

Promoting cassava consumption

Africans will have to change their farming and eating habits if they want to adopt cassava cultivation on a large scale. In Nigeria, farmers have been growing cassava roots primarily for their own consumption and this plays no significant role in the overall economy. The Nigerian government, however, wants to change that and see large amounts of cassava on sale at markets. This will not be easy because many Nigerian farmers who had been cultivating cassava on a large scale didn't make the sales they had hoped for. "There was no market for cassava and no one bought it.. That's why many farmers turned to other crops instead," says Alaji Takingari.

A dried up tree surounded by a few houses
Climate change is a problem for many African farmersImage: Norbert Jürgens

The government in Abuja wants now to reward bakers who use at least 40 percent cassava flour with tax cuts. The aim is become independent from expensive wheat and rice imports from abroad. The idea is not new. Almost ten years ago, former Nigerian President Obasanjo told bakers to bake their bread with at least ten percent of cassava flour. But because it wasn't as soft as bread made from wheat flour, the cassava-mix bread didn't sell well. But this hasn't discouraged the current government. President Goodluck Jonathan has promised to eat only cassava bread as long as he is in office.

Author: Vanessa Herrmann/al
Editor: Susan Houlton