Drought-resilient tuber helping farmers weather dry spells

It is the harvest season at Ngomeni, a farming community deep in the rural villages of Kitui County. Here, the bounty being harvested is neither maize, which serves as the region’s staple food, nor is it goats, the second most important economic activity in the area.

Instead, it’s mathunzu; a local name for the root tubers of lindau, a perennial herbaceous wild plant that stands as the heart of the semi-arid region’s resilient response to the challenges posed by climate change.

“Mathunzu, much like cassava, serves as a lifeline for our livestock. During the dry spells, we turn to the tubers to sustain our livestock. We harvest the tubers in August and September after which we store them in granaries. When our animals feed on mathunzu, they can go for at least five days without requiring water,” said Mary Mwilinga, a peasant farmer in Kavuti Village.

Known scientifically as Thunbergia Guerkeana Lindau, the black-eyed Susan vine is found in semi-arid regions of Ethiopia, Kenya, Tanzania and Somalia. Although it is easy to identify during the rainy season because of its showy flowers, which moths and other pollinators find irresistible, the climbing plant becomes hard to identify in dry seasons as it sheds leaves. “This is the climbing plant which produces mathunzu,” Ms Mwilinga said, pointing at the grey stem of a plant climbing on an acacia tree.

Armed with a hoe, Ms Mwilinga demonstrates how to harvest mathunzu, a tradition passed down to her by her grandfather.

As she digs them up, we learn that mathunzu are normally burrowed right below the surface of the vine, which makes their harvesting easy. Some can be as heavy as 20 kilogrammes while others are light. “We are not supposed to exhaust all the tubers so that it survives. The tubers need to be peeled and cut into small sizes to enhance their palatability. We then serve them in shallow containers such as a basin or a wheelbarrow to avoid contamination,” Ms Mwilinga offered. She uses the tubers to fatten her oxen during the dry spell then sell them at premium prices.

At the rest of the country reeled under the weight of the prolonged drought until last year, Ms Mwilinga and many of her neighbours were smiling all the way to the bank. Their animals fetched good prices in the market because they remained healthy. “Tens of traders from other parts of the country came here in search for mathunzu and acacia pods. A wheelbarrow filled with mathunzu fetches between Sh600 and Sh1,000. Often times, it takes only two big ones to fill a wheelbarrow. The number increases depending on the size of the tubers,” said Ben Mutuku, a boda boda rider.

Joseph Muia, a peasant farmer in Kiteng’ei Village which borders Tsavo East National Park in Makueni County, took a keen interest in mathunzu in 2010 after establishing that antelopes, dikdiks and goats scrambled for them when the lands were parched. He uses them to sustain his livestock.

 In the neighbouring Kitui County, mathunzu are at the centre of an aggressive campaign to promote the welfare of donkeys, one of the most important animals in the semi-arid region. The campaign, which is spearheaded by the Catholic Diocese of Kitui, entails changing the negative attitude towards the best of burden and addressing the health concerns as well as nutritional needs during the dry spell. “We advise farmers to use mathunzu and acacia pods to feed donkeys during dry spells when pastures and conventional feed is depleted,” said Ambrose Musyimi, the manager of  Mtunze Punda Daima Project, which is undertaken by Caritas, the development wing of the Catholic Church, across Kitui County.

Although there is little known about the nutritional value of mathunzu, a study on the tuber commissioned by the Catholic Diocese of Kitui last year shows that it is rich in fibre, carbohydrates and crude protein and water. “The study, which was done by scientists at the Kenya Agriculture and Livestock Research Organisation, confirms that the root tuber is a super feed,” said Mr Musyimi.

 The promise shown by the drought-resistant plant notwithstanding, scientists and conservationists have not taken a keen interest on it.

According to Lawrence Matolo, the chairman of the Agriculture Society of Kenya in Kitui, Machakos and Makueni counties and a former lecturer at Machakos University, the vine is popular among many communities across the country for its root tubers. He developed interest in the plant in 2009 after learning about its place among herders in Makueni County. He led a team of scientists that saw the plant identified at the National Museums of Kenya. But their efforts to domesticate the plant at the Machakos Agricultural Training Centre have failed. “Apart from providing livestock with water, the tuber provides them with carbohydrates, which sustain the animals for hours,” Mr Matolo told Health Nation. Scientists at the Kenya Forest Research Institute (Kefri) bet big on the growing awareness on the utility of mathunzu in promoting environmental conservation. To ensure that farmers d
o not run out of mathunzu, scientists discourage deforestation. “The lindau vine enhances soil structure and prevents soil erosion by holding the soil together. Since this vine is a climber, it only thrives in forested areas. This means that deforestation is its major threat. At the same time, we advise farmers to spare some of the tubers while harvesting. The spared tubers provide the plant with the food it requires to survive the drought and thrive ahead of the rainy season when it becomes lush,” offers Josephine Musyoki, a scientist at Kefri. She revealed that the agency was working towards promoting the domestication of the vine.

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