Nairobi: In an ambitious move to eradicate the invasive cactus plant, Laikipia North residents have devised an innovative and profitable means of containing the retrogressive weed. The residents have finally found an economically sound method of reducing the spread of the thorny plant, which they now use as raw material for the production of biogas.
According to Kenya News Agency, for decades, cactus plants have colonized hundreds of thousands of acres of land in the pastoral areas, shocking their grazing fields and killing livestock when consumed due to their thorny nature. "The invasive opuntia stricta spread very quickly in our land and homesteads, forcing some families to abandon their homes. It's a destructive plant, mostly affecting sheep which renders their ability to feed difficult," says James Masaine, a resident.
The cactus, introduced to Kenya by the colonial administration, has been blamed for causing deaths to livestock that feed on its brightly purple-colored fruit with tiny spines, resulting in injuries to the animals' digestive system. In a bid to remove the invasive species and save their land, residents have been using mechanical and chemical methods with minimal success.
In 2016, a biological approach was introduced with predator insects-cochineal, brought in from South Africa to control the spread. However, a project supported by Jomo Kenyatta University of Agriculture and Technology (JKUAT) is providing double benefits to the locals, minimizing the spread of the succulent weed and utilizing it in the generation of clean energy using simple technology.
According to Prof. Willis Owino from JKUAT, they started the initiative of removing cactus weed with a pilot project for two households two years ago in Makurian location within Maiyanat Community Land, which has expanded to 30 households. This move has led them to minimize usage of wood fuel as a source of energy. "The cactus species we have in Kenya is invasive, and this necessitated the need of finding out the solution of addressing the challenges associated with this plant in Laikipia. Women informed us that fuel was a major drawback, which informed piloting a biogas project in two households to see how it would perform before rolling out to other areas," reveals Prof. Owino.
The project has since been embraced by women to generate biogas, where they first chop the succulent plant and put it in a grinding machine to produce slurry, which they later feed into a bio-digester. Sayanat Kuraru highlights that they are now assured of efficient cooking, devoid of adverse health effects associated with wood smoke and also walking for long distances to fetch firewood. "We were walking for long distances to fetch firewood; we have now benefited from biogas. There is now a big change compared to using wood fuel, promoting good health and cooking efficiency. Woodfuel had soot which affected our eyes," she notes.
The semi-arid area has in recent years lost dozens of trees, felled for firewood and charcoal, and as a source of fodder during drought. Prof. Owino emphasizes that in case the invasive cactus eradication is complete, the introduction of spineless cactus would be ideal for the residents in future.
A research done by Chuka University in 2020 titled "Cactus Invasion: A Threat to Biodiversity and Food Security," shows that invasive cactus occupies 17,000 acres of land in Naibunga conservancy in Laikipia and invades at least two kilometers per year.