Riparian trees and some Napier grass. River is in the back. (Manuel Fischer (Tigithi Primary School))
At the foot slopes of Mt. Kenya a farmer has developed a technology to protect the own land plot from riverbank erosion. The technology consists of three main measures: A wall along the riverbed, trees that are aligned on the wall as well as beside it and Napier grass wildly scattered between the trees. The wall was built on a highly exposed spot of the riverbank. Trees along and beside the wall ensure its stability. The combination of the two measures results in an effective protection of the riverbank in terms of erosion. Side effects of the technology are higher runoff during the dry season, better water quality due to less erosion and an improved riparian habitat for animals and plants.
Purpose of the Technology: For a small scale farmer, planting of trees can have advantages in an economic, an ecologic and an aesthetic point of view. The trees stabilize the soil, allow the riparian vegetation to establish, and prevent major damages through flooding. Furthermore, there are several advantages of an intact riparian zone, such as enhanced biodiversity, increased water quality as well as retention of agrochemicals. The trees also work as a kind of bank account, since the prices for wood are quite high. Trees can be cut and sold from time to time to generate an income that can be used for further investments like local entrepreneurship or building houses for family members. Last but not least, the farmer emphasized the beautiful appearance of the trees including the relatively cool micro- climate the trees are able to provide during the hot months of the dry period.
Establishment / maintenance activities and inputs: The trees were planted during the rainy season. Braches are pruned regularly and provide mulch material as well as fire wood. When trees are reaching maturity they will selectively be cut and replanted. The Napier grass is cut regularly for fodder to be feed to animals. At this particular time, there is a regular hay yield (weed). Seedlings for trees and the grasses are produced on site. Occasional pruning ensures fuel wood supply.
Natural / human environment: The plot is situated at the western side of Mt. Kenya in its foot zone, a moderate hilly region. Actually, the foot zone is a transition area between the humid mountain forest above elevations of 2500 m.a.s.l and the semi-arid savannah zone below 2000 m a.s.l. Although the region is located in the rain shadow of Mt. Kenya, there is just enough precipitation (740mm) to sustain rain fed agriculture and the farmers even benefit from a water project. During the last decades, the region has experienced a still continuing population growth which increases population pressure in the area. The good accessibility and the moderate tourism allow even off-farm income-generation.
Location: Naro Moru, Kenya/Central Province, Kenya
No. of Technology sites analysed:
Spread of the Technology: evenly spread over an area (approx. < 0.1 km2 (10 ha))
In a permanently protected area?:
Date of implementation: less than 10 years ago (recently)
Type of introduction
| Specify input | Unit | Quantity | Costs per Unit (USD) | Total costs per input (USD) | % of costs borne by land users |
| Labour | |||||
| Setting up a tree nursery | Persons/day | 5.0 | 3.3333 | 16.67 | 100.0 |
| Planting seedlings | Persons/day | 25.0 | 3.3333 | 83.33 | 100.0 |
| Establishment of wall | Persons/day | 5.0 | 3.3333 | 16.67 | 100.0 |
| Total costs for establishment of the Technology | 116.67 | ||||
| Total costs for establishment of the Technology in USD | 116.67 | ||||
| Specify input | Unit | Quantity | Costs per Unit (USD) | Total costs per input (USD) | % of costs borne by land users |
| Labour | |||||
| Replanting trees | Persons/day | 3.0 | 3.3333 | 10.0 | 100.0 |
| Cutting the Napier grass and pruning trees | Persons/day | 12.0 | 3.33333 | 40.0 | 100.0 |
| Total costs for maintenance of the Technology | 50.0 | ||||
| Total costs for maintenance of the Technology in USD | 50.0 | ||||
Napier grass yield has increased
Before, there was only little wood production
