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Technologies
Inactive

Riverbed reclamation & silt trapping for sugarcane [Kenya]

Kyanda (Kikamab)

technologies_1096 - Kenya

Completeness: 69%

1. General information

1.2 Contact details of resource persons and institutions involved in the assessment and documentation of the Technology

Key resource person(s)

SLM specialist:
SLM specialist:

Ngati Mbuvi

MOARD

Kenya

SLM specialist:

Mwendwa Linus

MOARD

Kenya

Name of the institution(s) which facilitated the documentation/ evaluation of the Technology (if relevant)
Food and Agriculture Organization of the United Nations (FAO) - Italy

1.3 Conditions regarding the use of data documented through WOCAT

When were the data compiled (in the field)?

17/04/2000

The compiler and key resource person(s) accept the conditions regarding the use of data documented through WOCAT:

Ja

2. Description of the SLM Technology

2.1 Short description of the Technology

Definition of the Technology:

Silt harvesting on riverbeds to maximise sugarcane growing in semi arid area

2.2 Detailed description of the Technology

Description:

The technology first involves fencing off part of a riverbed with cut thorn scrub in order to keep livestock away. The enclosed area is then mulched with brushwood and herbaceous materials in places. Sugar cane is planted and harvested piecemeal when mature. Kamuti plants a perennial grass (Cynodon dactylon) between the canes to help bind the sand. This exercise has been done, incrementally, over a series of seasons, enclosing an increasingly large area. When the rains return and the river flows, floodwater passes through and over the sugar cane and silt is deposited as the flow is slowed.

Purpose of the Technology: This initiative is categorized as an agronomic/vegetative measure, for reclamation of land. Its purpose is to increase water stored in the soil and to increase fertility by sediment harvesting, as a way of making land productive, while simultaneously addressing riverbed erosion. Farm income increase from the sale of sugar cane is the main production/ socio-economic benefit, while the ecological benefits include sediment accumulation, soil (ie riverbed and bank) loss reduction, soil cover improvement, increase in soil moisture and increase in soil fertility.

Establishment / maintenance activities and inputs: The action involves cutting tree branches, trimming pegs about 1m long, and hammering these pegs into the bed of the sand river, parallel to the bank, enclosing a long narrow strip. This initial strip may be 10 metres wide in a riverbed of 100 meters wide. The tree branches and trimmings are used to form a brushwood-netting barrier, which protects the area from livestock, and simultaneously slows the river flow and traps sediments. To further strengthen the barrier, star grass (Cynodon dactylon) is planted along the line of the fence. Inside the fenced-off area, sugar cane cuttings are buried at a depth of 0.4 m, and the same grass planted between the canes. The area is mulched with brushwood, which rots down to increase organic matter in the soil. These cuttings sprout and an intercrop of grass and sugar cane is the result. Maintenance comprises repairing the fence and cutting grass for mulching. No special tools are required. To be effective, the technology requires mulching every season, as the old mulch is covered by the silt load during the rainy period. The perimeter fence is maintained seasonally and requires considerable material. Occasionally when the rainfall is heavy, the sugar cane is swept away by floods and needs replacing.

Natural / human environment: The farm on which this technology is applied is in the arid far-north of Mwingi District. During the rainy season the farm can be inaccessible. The farmer, who is over 60 years of age, lives with his wives and children in what effectively forms a mini-village. The annual average rainfall in this area is barely 500 mm, and famine years are common. Temperatures are consistently high. The farm borders a dry sand riverbed.

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

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.):

Farmer own intiative

3. Classification of the SLM Technology

3.1 Main purpose(s) of the Technology

  • improve production
  • reduce, prevent, restore land degradation

3.2 Current land use type(s) where the Technology is applied

Cropland

Cropland

  • Perennial (non-woody) cropping
Comments:

Major land use problems (compiler’s opinion): Extensive grazing of animals/unit area, uncontrolled felling and burning of tree in land preparation, low soil fertility due to continous cultivation without conservation

Major land use problems (land users’ perception): Low yields hence opening of large areas for cultivation. Difficult soils, hence ploughing during the rains. Infertile soils.

3.3 Further information about land use

Water supply for the land on which the Technology is applied:
  • rainfed
Number of growing seasons per year:
  • 2
Specify:

Longest growing period in days: 75 Longest growing period from month to month: Mar - May Second longest growing period in days: 60 Second longest growing period from month to month: Nov - Dec

3.4 SLM group to which the Technology belongs

  • minimal soil disturbance
  • water harvesting

3.5 Spread of the Technology

Specify the spread of the Technology:
  • evenly spread over an area
If the Technology is evenly spread over an area, indicate approximate area covered:
  • < 0.1 km2 (10 ha)
Comments:

Total area covered by the SLM Technology is 0.01 m2.

This technology is along a riverbed and it is not adapted by other farmers

3.6 SLM measures comprising the Technology

agronomic measures

agronomic measures

  • A6: Others
vegetative measures

vegetative measures

  • V2: Grasses and perennial herbaceous plants
structural measures

structural measures

  • S6: Walls, barriers, palisades, fences
management measures

management measures

  • M1: Change of land use type
Comments:

Main measures: agronomic measures, vegetative measures, management measures

Type of agronomic measures: mulching, zero tillage / no-till

3.7 Main types of land degradation addressed by the Technology

soil erosion by water

soil erosion by water

  • Wg: gully erosion/ gullying
chemical soil deterioration

chemical soil deterioration

  • Cn: fertility decline and reduced organic matter content (not caused by erosion)
Comments:

Main type of degradation addressed: Wg: gully erosion / gullying

Secondary types of degradation addressed: Cn: fertility decline and reduced organic matter content

4. Technical specifications, implementation activities, inputs, and costs

4.1 Technical drawing of the Technology

4.2 Technical specifications/ explanations of technical drawing

Reclaiming part of sand river bed with Sugar cane

Kenya

Technical knowledge required for field staff / advisors: moderate

Technical knowledge required for land users: high

Main technical functions: increase / maintain water stored in soil

Secondary technical functions: sediment retention / trapping, sediment harvesting, increase in soil fertility

Mulching
Material/ species: grasses
Quantity/ density: 2
Remarks: grass scattered

Grass species: stargrass

Change of land use type: fencing off portion of river bed

4.3 General information regarding the calculation of inputs and costs

other/ national currency (specify):

Kenya shilling

Indicate exchange rate from USD to local currency (if relevant): 1 USD =:

70.0

Indicate average wage cost of hired labour per day:

1.50

4.4 Establishment activities

Activity Type of measure Timing
1. fencing Vegetative after rains
2. mulching with bushes Vegetative before rains
3. planting of sugarcane Vegetative dry season
4. cuting grass for mulch Vegetative rainy season
5. fencing riverbed to keep off animals Management after rain
6. planting grass Management after rain

4.5 Costs and inputs needed for establishment

Comments:

Duration of establishment phase: 24 month(s)

4.6 Maintenance/ recurrent activities

Activity Type of measure Timing/ frequency
1. fencing Agronomic dry season / when height goes down
2. mulching with trash Agronomic dry '' / after clearing
3. grass planting Agronomic dry / before rains
4. sugarcane planting Agronomic wet / end of rain
5. collection of mulch Agronomic dry / biannual
6. fencing Vegetative after rain /biannual
7. cutting grass for mulch Vegetative rainy /biannual
8. scatterin thorn bushes Vegetative during rain /biannual
9. fencing Management after rain / each cropping season
10. spreading brushwood Management after / annual

4.7 Costs and inputs needed for maintenance/ recurrent activities (per year)

Comments:

Machinery/ tools: oxen plough, 2 pangas , 2 hoes

the above cost were calculated in terms of purchase of tools,material and manday used.

4.8 Most important factors affecting the costs

Describe the most determinate factors affecting the costs:

labour affects cost as it is required in large quantities

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
  • 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)
Topsoil organic matter:
  • medium (1-3%)
  • 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.

Topsoil organic matter: Becomes medium after the technology

Soil drainage / infiltration is medium - good

Soil water storage capacity is very low - medium

5.6 Characteristics of land users applying the Technology

Off-farm income:
  • 10-50% of all income
Relative level of wealth:
  • poor
  • average
Level of mechanization:
  • manual work
  • animal traction
Indicate other relevant characteristics of the land users:

Population density: < 10 persons/km2

Annual population growth: 3% - 4%

5% of the land users are very rich and own 33% of the land.
10% of the land users are rich and own 25% of the land.
30% of the land users are average wealthy and own 12% of the land.
40% of the land users are poor and own 8% of the land.
15% of the land users are poor and own 21% of the land.

Off-farm income specification: most of harvest are low and hence dependent on off farm income.

Level of mechanization: Animal traction is used for assembling the thorny bushes and for marking farrows

5.8 Land ownership, land use rights, and water use rights

Land ownership:
  • communal/ village
  • individual, not titled
Land use rights:
  • open access (unorganized)
  • communal (organized)

6. Impacts and concluding statements

6.1 On-site impacts the Technology has shown

Socio-economic impacts

Production

crop production

decreased
increased
Comments/ specify:

Sugar cane

Income and costs

farm income

decreased
increased
Comments/ specify:

Sugar cane

Ecological impacts

Water cycle/ runoff

surface runoff

increased
decreased
Quantity before SLM:

60

Quantity after SLM:

20

Soil

soil moisture

decreased
increased

soil cover

reduced
improved

soil loss

increased
decreased
Quantity before SLM:

12

Quantity after SLM:

5

nutrient cycling/ recharge

decreased
increased

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:

very positive

6.5 Adoption of the Technology

  • 1-10%
If available, quantify (no. of households and/ or area covered):

30 households (1% of the area stated)

Of all those who have adopted the Technology, how many have did so spontaneously, i.e. without receiving any material incentives/ payments?
  • 90-100%
Comments:

30 land user families have adopted the Technology without any external material support

Comments on spontaneous adoption: estimates

There is a moderate trend towards spontaneous adoption of the Technology

Comments on adoption trend: after farmer tour organised by the PFI most are attempting. At least five farmers had adopted the innovation by the beginning of 1999 (exact figures not available). This is a particularly site-specific system, and thus wide replication is simply not possible. It is only relevant to those who have farms bordering sand rivers with wide beds.

6.7 Strengths/ advantages/ opportunities of the Technology

Strengths/ advantages/ opportunities in the compiler’s or other key resource person’s view
This innovation demonstrates how productive use can be made of sub-surface moisture in sand rivers in arid areas while simultaneously protecting the riverbed and bank from erosion
Farm income increase through land reclamation

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?
Planting within a riverbed is, strictly speaking,
against regulations.
Such technologies should not be attempted without consulting the local agricultural office.
The fence is constructed with thorn bush cuttings which have to be constantly replenished A live fence is recommended as an alternative to constantly having to replenish the fence with cut thorn
bush. The fence is required to avoid grazing of the cane by domestic livestock.

7. References and links

7.2 References to available publications

Title, author, year, ISBN:

Farm management Guidelines. 1989.

Available from where? Costs?

MOA, 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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