In the mid-seventies, the government introduced Prosopis Juliflora, an evergreen drought-tolerant shrub, in arid parts of the country, to combat desertification and soil erosion.
The shrub commonly known as mathenge, is quite aggressive, restoring an area’s vegetation in no time, giving an evergreen canopy that provides cool shades for herders and their animals during scorching days. It also serves as animal fodder and wood fuel.
This is why it became an immediate hit with hundreds of residents of Garissa, Tana River and Baringo, who planted it in their homesteads. Then years later, they protested against the plant, saying that their goats lost teeth after chewing the weed’s pods.
Francis Cherono, a farmer in Marigat, Baringo County, says they did not know that the plant could be so noxious and invasive. The shrub invaded farms and grazing fields, suppressed pasture germination and diverted river courses.
“More sadly, goats who consumed its sugary and sticky pods over time lost their teeth and could no longer eat and ended up dying,” he said.
Mathenge pods are very sugary and sticky, causing animal teeth to rot when consumed over time. To make matters worse, the weed that spread alarmingly to dominate the local landscape, had thorns so poisonous, that when they pricked an animal, the affected area had to be chopped off.
“It soon became an invasive weed, with only negatives,” said Mr Cherono, who practises mixed farming, combining vegetable farming with rearing poultry and dairy cows.
Now, after several years of distress, farmers are learning to live with the dreaded weed. Through pruning and curling, farmers allow only a few shrubs to thrive to allow for growth of pasture.
For a dairy farmer like Mr Cherono, pruning and thinning the tree has proved effective in pasture regeneration.
“Under a training programme known as Farmer Managed Natural Regeneration, we have managed to tame and control the infamous shrub,” he said.
Farmer Managed Natural Regeneration is a project by the Kenya Forestry Research Institute (KEFRI) and World Vision to improve food security by promoting restoration of natural resources, pasture, forests, and indigenous trees in semi-arid areas. The project has so far benefited 600 farmers across three counties.
Festus Chirchir, who trains farmers to co-exist with mathenge, says that while farmers see it an evil plant, they are encouraging them to see the good in it.
“If well managed the plant can give more benefits than harm. Farmers need to reduce the density to encourage undergrowth so that livestock can find pasture,” he said, adding that they also encourage farmers to manage the number of livestock by acquiring improved breeds.
Dennis Rotich, the assistant chief of Chelaba Sub-location, says that locals are slowly learning to co-exist with the stubborn shrub by either uprooting young shrubs, or using big shrubs to host beehives.
“Non-governmental organisations such as World Vision and Arid Lands have been training us. The trees have good shade and flowers making them a favourite with bees, so we are using the shrub to enhance beekeeping,” said Mr Rotich.
Farmers in Marigat have also learnt to use mathenge as fodder for their animals without it posing any harm.
Salina Kimaru explained that the plant only becomes a problem when exclusively fed to livestock.
“It poses no harm when mixed with grass and other pastures,” she said, adding that it is also a good source of wood fuel.
Last year, the fuel part was under threat after the government imposed a moratorium which halted logging of trees including mathenge shrubs and burning of charcoal. But the Ministry of Environment has since exempted the shrub from the moratorium.
Two weeks ago, the ministry, the National Environment Management Agency, the Kenya Forestry Research Institute, the Kenya Forest Service and the Baringo County government formed a technical team to develop a model to guide management, utilisation and trade of mathenge-based products.
The recommendations the team comes up with, will be replicated in other affected counties such as Tana River and Garissa.
KEFRI Assistant Director for Baringo County Evans Bukasa explained that their researchers have been studying how best to utilise the noxious mathenge weed.
“The weed’s pods have high sugar concentration and if consumed by goats and cows, they make the teeth rot and fall off. But we are working with other partners to sensitise farmers on its benefits,” he said.