One of the soil bunds in Isiolo county. Photo credit Franklin Lemasulani, PlantVillage field officer in Isiolo County.
Francis Lekirimpoto, a PlantVillage field officer working to help pastoralists in Samburu East Sub-County in Samburu County, says the rainwater trapping technique improves soil moisture levels, prevents soil erosion, and increases soil fertility.
"Water collects itself at the circumference of the semi-circle, run-off water comes with nutrients from the top of the hill, and its settlement at the soil bund creates fertile soil necessary for crop planting," he explained.
Rainy seasons in northern Kenya last from mid-March to May and November to December. Community members have been urged to build soil bunds to harvest water during these seasons.
Soil bunds after digging. Photo Credit Franklin Lemasulani a PlantVillage field officer in Isiolo County.
When it rains, the bunds capture the runoff water and allow it to seep into the soil, increasing soil moisture levels. If the space behind the bunds fills up, the water can either overflow to the lower tier of bunds or be discharged into a safe drainage waterway.
PlantVillage aims to use the soil bunds as planting areas for grass and trees.
Users of the soil bunds are advised to fence the area to prevent access by animals that may end up eating the grass and trees. These can be with invasive weeds like Prosopsis juliflora.
"This area is prone to invasions from goats, sheep, cows, and other animals that may eat up the vegetation; we advise creators to fence them; we believe creating soil bunds will reclaim our community land," said Franklin Lemasulani, a PlantVillage field officer in Isiolo County.
PlantVillage field officers marking on the ground before digging a soil bund. Photo credit Evans Kangiro.
A total of 55 soil bunds have already been created by the organization's team in collaboration with community members, as the goal of more than 150 soil bunds is targeted before the end of next April.
How to create a soil bund
Mr. Lekirimpoto outlined the procedure for creating a soil bund using a tape measure, a spade, and a jembe.
Someone is set to dig several soil bunds.
For a single soil bund:
a). Start by marking a 6-meter line along the contour line, which will serve as the diameter of the bund.
b). Depending on the slope, the diameter of the bund can vary up to 6 meters.
c). Mark the diameter's center and draw a semi-circular curve where the tip meets the contour line.
d). Dig a shallow semi-circle and throw the soil on the lower side.
e). The bund should be about 20 cm deep in diameter, gradually decreasing in depth, and reaching the ground level at the tips.
A sketch diagram demonstrating measurements, spacing, and how to dig soil bunds. Diagram Courtesy Lemasulani, PlantVillage field officer in Isiolo County.
Apart from soil bunds, other projects launched by the organization to reclaim drought-stricken areas include the planting of drought-tolerant trees and grasses, as well as the wick irrigation project that was recently launched in Marsabit to help the area sustainably grow food.
This is a low cost and effective approach that the community can do resulting in rapid changes" said David Hughes, founder of PlantVillage and Direcror if the USAID Innovation Lab on Current and Emerging Threats to Crops.
Written by Dennis Avokoywa.