LAIKIPIA, Kenya

The Opuntia cactus in Kenya has become a thorn in the side for many residents as it slowly chokes their livelihoods.

With thick leafless and fleshy stems, the Opuntia cactus, which is covered in prickly sharp spines, has invaded thousands of hectares of grazing lands in arid and semi-arid parts of northern Kenya.

The plant, which cannot be eaten by camels, cows, goats or other livestock, spreads fast across the land taking up any water that could be used by natural vegetation, denying livestock nutritious pasture.

Its needle-like spines also kill other vegetation, a defensive mechanism that the cacti have to protect themselves.

“They will cling onto another plant and use it to grow, they will then kill the plant and grow to maturity and spread all over the area,” said Benjamin Kambi, a resident from the Loisaba area in the Laikipia county.

The 33-year-old man was up and about looking for pasture for his 29 goats and 13 sheep.

“It never used to be like this; 15 years ago, the plant was there but not in this intensity, now wherever we go, it is there, we don't have anywhere to get pasture.”

Across the land the cacti can be spotted as far as the eye can see, vehicles are not spared from the prickly thorn of them as they grow close to main roads and often scratch the paint job off vehicles.

 Threaten food security

A report by Eunice Githae from the Department of Biological Sciences at Chuka University in Kenya warns that invasive alien species are among the major threats to biodiversity, food security and human well-being.

Opuntia, commonly called prickly pear, is one of the most widespread and naturalized plants in the arid and semi-arid areas of Kenya, with extreme effects on rural livelihoods and the environment.

“They have a high ecological and competitive ability as well as efficient reproduction and dispersal mechanisms. In a new environment, such species prosper in absence of predators or parasites that would regulate their relative abundance,” the report said.

The plant, which depletes soil and water resources, and reduces the diversity of plants and animals has also threatened food security. It has been linked to livestock deaths, reduced forage, interference with grazing practices, increased costs of management, and reduced livestock yields.

“Effects on rural livelihoods are linked to the extra cost of management, reduced ecosystem productivity, increased threat to health and reduced utilities from natural resources. These impacts not only reduce biodiversity but also threaten food security and human well-being,” warned the report.

Making money from invasive cactus

Joseph Letunyoi, a Kenyan farmer from the Laikipia permaculture center, urged the youth to harvest the invasive plant and cash in on it.

Letunyoi is among Kenyans who are harvesting the plant and minting money from products that they make from it.

When processed, the cacti can produce fruit juice for home consumption, lotions, soaps, and many more products.

“The plant which grows in the rangelands of Laikipia has been bad news for us who are from pastoralist communities; it is very invasive and grows all over the landscape, killing grass and other shrubs,” Letunyoi said.

Letunyoi and his team collect the plants on a large scale, they harvest the fruits, and put them in a blender to separate the seed and the pulp.

It is from the pulp that the team makes juice, yoghurt, lotions, and other products, while the seeds are pressed for oil used to make soaps.

“When we use the seeds of the cactus, we are reducing how fast the plant spreads, so we are killing two birds with one stone”.

With the leaves remaining, they are crushed and processed in a bio-digester, producing methane gas for biogas, which is used by the community for heating and cooking.

“There is the social aspect; people are liking it for business, they can cook using the gas and they can have the juice and other foods from it, there is also the environmental and the economic aspect issue being tackled.”

Sap-sucking insect

The National Environment Management Authority (NEMA), a Kenyan government agency working with Arne Witt from the Centre for Agriculture and Biosciences International, and the Laikipia County government have launched the release of a biological agent superbug to help in the reduction of the Opuntia.

“NEMA in collaboration with the Laikipia County government launched a biological agent to get rid of Opuntia stricta, an invasive plant species that threaten to destroy the biodiversity of the region,” NEMA said in a statement.

“The cactus has affected public and private conservancies in the region among them Oljogi, which houses many iconic animals. The invasive cactus has displaced the native plant species and has prevented rehabilitation of degraded land,” it added.

NEMA hopes that the introduction of cochineal bugs, which are sap-sucking insects that feed solely on the cactus, will help reduce the spread of the invasive cactus. It also believes that the biocontrol will save costs and restore the land to local wildlife and livelihoods to Laikipia's farmers.