Gully Rehabilitation [Kenya]
- Creation:
- Update:
- Compiler: Kithinji Mutunga
- Editor: –
- Reviewers: David Streiff, Alexandra Gavilano
technologies_1488 - Kenya
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Expand all Collapse all1. General information
1.2 Contact details of resource persons and institutions involved in the assessment and documentation of the Technology
SLM specialist:
Kiio Jacqueline
MOARD
Kenya
land user:
Kirimi Patrick
MOARD
Kenya
SLM specialist:
Gitau Mary
MOARD
Kenya
1.3 Conditions regarding the use of data documented through WOCAT
The compiler and key resource person(s) accept the conditions regarding the use of data documented through WOCAT:
Yes
2. Description of the SLM Technology
2.1 Short description of the Technology
Definition of the Technology:
Erosion control by use of physical barriers and vegetative materials
2.2 Detailed description of the Technology
Description:
The innovation comprises control of gully erosion by use of constructed barriers (check dams) combined with vegetative materials. The end result is a stabilized gully that is prevented from advancing further. The system also involves fruit trees/banana establishment and fodder grass planting for structure stabilization. Establishment of the technology involves excavation of pits, planting fruit trees/bananas and grass cuttings.
Purpose of the Technology: This is a structural measure that is vegetated for stabilization. Its purpose is to rehabilitate a gully bed, through control of concentrated runoff by reduction of slope length and both trapping of runoff and sediment harvesting. The productive use of the innovation is mainly for perennial crops (fruit trees and
bananas) and for fodder production.
Establishment / maintenance activities and inputs: Earth check dams are constructed in the gully, using borrow spoil from square pits in the walls of the gully (see diagram). The earth embankment of the dams are then stabilized with grass. Pawpaws are planted on the original gully floor. Initially the innovator left the pits empty: now she plants bananas in them.The 5 check dams, each 1 m or more in height, are spaced at about 10 m apart in the gully. The excavated pits are about 1 m x 1 m wide and 1 m deep. Four pits are dug separately on each side of each check dam. Makarikari grass (Panicum coloratum var. makarikariensis) is used for stabilization, while bananas and pawpaws are planted within the rehabilitated area. When it rains, runoff generated from the neighbouring plots upstream flows down and is slowed by the check dams. The runoff passes around both wings of each embankment, filling and flowing through the pits. Sediment is trapped in the pits. Excess runoff flows on to the second embankment, then through the second set of pits and so on. Only during heavy rains does water pass through and out of the system, though its velocity is reduced. Thus the gully heals slowly with time and vegetation becomes established. Regular maintenance work is required, involving repair of broken sections from time to time, using manual labour with a panga, shovel and jembe. Also of importance is manure application every season to the planted areas before the rains to sustain fertility and thus productivity.
Natural / human environment: Kalekye Mutua is a single household head in her mid thirties. Although she has no partner to help support her three children, she manages quite well through farming her 6 hectares of land - where she grows various crops and keeps a few local cattle. She had a small trading venture but has recently abandoned
this. Kalekye is not amongst the poorest in Mwingi, but represents a number of female-headed households who prosper through hard work and enterprise. In fact she even employs labourers part-time to help with the farming activities.
2.3 Photos of the Technology
2.5 Country/ region/ locations where the Technology has been applied and which are covered by this assessment
Country:
Kenya
Region/ State/ Province:
Eastern Province
Specify the spread of the Technology:
- evenly spread over an area
If precise area is not known, indicate approximate area covered:
- < 0.1 km2 (10 ha)
Comments:
a very small portion of the individual farm is covered by the technology
Map
×2.6 Date of implementation
If precise year is not known, indicate approximate date:
- more than 50 years ago (traditional)
2.7 Introduction of the Technology
Specify how the Technology was introduced:
- as part of a traditional system (> 50 years)
Comments (type of project, etc.):
farmers own intiative
3. Classification of the SLM Technology
3.1 Main purpose(s) of the Technology
- reduce, prevent, restore land degradation
3.2 Current land use type(s) where the Technology is applied
Cropland
- Perennial (non-woody) cropping
- Tree and shrub cropping
Perennial (non-woody) cropping - Specify crops:
- banana/plantain/abaca
Tree and shrub cropping - Specify crops:
- pome fruits (apples, pears, quinces, etc.)
Number of growing seasons per year:
- 2
Specify:
Longest growing period in days: 60 Longest growing period from month to month: Oct - Dec Second longest growing period in days: 75 Second longest growing period from month to month: Mar - May
Comments:
Fruit trees / shrubs species: pawpaws (Asimina triloba)
Perennial crops species: bananas
Major land use problems (compiler’s opinion): soil erosion, overgrazing, declining soil fertility
Major land use problems (land users’ perception): low yields
3.4 Water supply
Water supply for the land on which the Technology is applied:
- rainfed
3.5 SLM group to which the Technology belongs
- improved ground/ vegetation cover
- water harvesting
- water diversion and drainage
3.6 SLM measures comprising the Technology
vegetative measures
structural measures
- S3: Graded ditches, channels, waterways
Comments:
Main measures: vegetative measures
Secondary measures: structural measures
3.7 Main types of land degradation addressed by the Technology
soil erosion by water
- Wg: gully erosion/ gullying
3.8 Prevention, reduction, or restoration of land degradation
Specify the goal of the Technology with regard to land degradation:
- reduce land degradation
4. Technical specifications, implementation activities, inputs, and costs
4.1 Technical drawing of the Technology
Technical specifications (related to technical drawing):
Gully under reclamation: note flow of runoff
Kenya
Technical knowledge required for field staff / advisors: low
Technical knowledge required for land users: moderate
Main technical functions: control of concentrated runoff: retain / trap, control of concentrated runoff: impede / retard
Secondary technical functions: reduction of slope angle, improvement of ground cover, increase of infiltration, water harvesting / increase water supply, sediment retention / trapping, sediment harvesting
Fruit trees / shrubs species: pawpaws
Perennial crops species: bananas
Slope (which determines the spacing indicated above): 10.00%
If the original slope has changed as a result of the Technology, the slope today is (see figure below): 5.00%
Construction material (earth): Local soil excavated from pits on the side of the gully
Construction material (other): Grass for stabilization Makarikari grass prefeered
Slope (which determines the spacing indicated above): 10%
If the original slope has changed as a result of the Technology, the slope today is: 8%
Vegetation is used for stabilisation of structures.
4.2 General information regarding the calculation of inputs and costs
other/ national currency (specify):
kenya shillings
If relevant, indicate exchange rate from USD to local currency (e.g. 1 USD = 79.9 Brazilian Real): 1 USD =:
70.0
Indicate average wage cost of hired labour per day:
2.14
4.3 Establishment activities
Activity | Timing (season) | |
---|---|---|
1. | digging banana holes | dry season |
2. | acquisition of grass cuttings | dry season |
3. | acquisition of banana cuttings | before |
4. | planting of grass and bananas | onset of rain |
5. | manure application | before the rains |
6. | Excavation | Dry season |
4.4 Costs and inputs needed for establishment
Comments:
Duration of establishment phase: 24 month(s)
4.5 Maintenance/ recurrent activities
Activity | Timing/ frequency | |
---|---|---|
1. | repair of broken structures | after rains /seasonally |
2. | weeding | during rains /twice /season |
3. | banana prunning | after rains /biannually |
4. | manure application | dry season /annually |
5. | Repair of broken sections | during /after rains/seasonally |
6. | Stabilization with grass | during rains/when required |
4.6 Costs and inputs needed for maintenance/ recurrent activities (per year)
Comments:
1100 banana/ fruit trees holes/ha
4.7 Most important factors affecting the costs
Describe the most determinate factors affecting the costs:
slope, soil type, timeliness of operation
5. Natural and human environment
5.1 Climate
Annual rainfall
- < 250 mm
- 251-500 mm
- 501-750 mm
- 751-1,000 mm
- 1,001-1,500 mm
- 1,501-2,000 mm
- 2,001-3,000 mm
- 3,001-4,000 mm
- > 4,000 mm
Agro-climatic zone
- semi-arid
5.2 Topography
Slopes on average:
- flat (0-2%)
- gentle (3-5%)
- moderate (6-10%)
- rolling (11-15%)
- hilly (16-30%)
- steep (31-60%)
- very steep (>60%)
Landforms:
- plateau/plains
- ridges
- mountain slopes
- hill slopes
- footslopes
- valley floors
Altitudinal zone:
- 0-100 m a.s.l.
- 101-500 m a.s.l.
- 501-1,000 m a.s.l.
- 1,001-1,500 m a.s.l.
- 1,501-2,000 m a.s.l.
- 2,001-2,500 m a.s.l.
- 2,501-3,000 m a.s.l.
- 3,001-4,000 m a.s.l.
- > 4,000 m a.s.l.
5.3 Soils
Soil depth on average:
- very shallow (0-20 cm)
- shallow (21-50 cm)
- moderately deep (51-80 cm)
- deep (81-120 cm)
- very deep (> 120 cm)
Soil texture (topsoil):
- coarse/ light (sandy)
Topsoil organic matter:
- low (<1%)
If available, attach full soil description or specify the available information, e.g. soil type, soil PH/ acidity, Cation Exchange Capacity, nitrogen, salinity etc.
Soil fertility is low
Soil drainage / infiltration is good
Soil water storage capacity is low
5.6 Characteristics of land users applying the Technology
Off-farm income:
- less than 10% of all income
Level of mechanization:
- manual work
Indicate other relevant characteristics of the land users:
Population density: < 10 persons/km2
Annual population growth: 2% - 3%
1% of the land users are very rich and own 10% of the land.
4% of the land users are rich and own 20% of the land.
25% of the land users are average wealthy and own 40% of the land.
30% of the land users are poor and own 20% of the land.
40% of the land users are poor and own 10% of the land.
Off-farm income specification: the are few members of the household who are in formal employment
5.8 Land ownership, land use rights, and water use rights
Land ownership:
- individual, not titled
Land use rights:
- individual
6. Impacts and concluding statements
6.1 On-site impacts the Technology has shown
Socio-economic impacts
Production
fodder production
production area
Income and costs
farm income
Comments/ specify:
Sale of bananas
Ecological impacts
Water cycle/ runoff
surface runoff
Quantity before SLM:
60
Quantity after SLM:
10
Soil
soil moisture
soil cover
soil loss
Quantity before SLM:
610
Quantity after SLM:
1
6.4 Cost-benefit analysis
How do the benefits compare with the establishment costs (from land users’ perspective)?
Short-term returns:
slightly positive
Long-term returns:
very positive
How do the benefits compare with the maintenance/ recurrent costs (from land users' perspective)?
Short-term returns:
positive
Long-term returns:
positive
6.5 Adoption of the Technology
- single cases/ experimental
If available, quantify (no. of households and/ or area covered):
1 household
Of all those who have adopted the Technology, how many did so spontaneously, i.e. without receiving any material incentives/ payments?
- 91-100%
Comments:
100% of land user families have adopted the Technology without any external material support
There is no trend towards spontaneous adoption of the Technology
Comments on adoption trend: Kalekye only started the innovation two years ago, and while there has been a policy of taking women’s groups to visit Kalekye, this is a relatively recent occurrence (starting approximately a year ago). Despite the visitors obviously being inspired, there have been no reports as yet of direct adoption of the technology.
6.7 Strengths/ advantages/ opportunities of the Technology
Strengths/ advantages/ opportunities in the compiler’s or other key resource person’s view |
---|
Reclamation of land for production of fodder and bananas How can they be sustained / enhanced? Possible improvements would include planting improved fruit trees that are rapidly maturing and yield more: grafted mangoes for example |
6.8 Weaknesses/ disadvantages/ risks of the Technology and ways of overcoming them
Weaknesses/ disadvantages/ risks in the compiler’s or other key resource person’s view | How can they be overcome? |
---|---|
High labour requirements |
7. References and links
7.1 Methods/ sources of information
7.2 References to available publications
Title, author, year, ISBN:
Farm Management handbook of Kenya Vol II
Available from where? Costs?
Ministry of Agiculture, Nairobi
Title, author, year, ISBN:
Kithinji M., Critchley W. 2001. Farmers' initiatives in land husbandry: Promising technologies for the drier areas of East Africa. RELMA Technical Report series no. 27
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