Boundary Hedgerows [Kenya]
- Creation:
- Update:
- Compiler: Paul Kahiga
- Editor: –
- Reviewers: Fabian Ottiger, Alexandra Gavilano
Boundary Hedgerows
technologies_1740 - 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:
Gathenya Mwangi
Jomo Kenyatta University of Agriculture and Technology
Kenya
SLM specialist:
Home Patrick
Jomo Kenyatta University of Agriculture and Technology
Kenya
SLM specialist:
Chege Timothy
Jomo Kenyatta University of Agriculture and Technology
Kenya
SLM specialist:
Omwange Abamba
Jomo Kenyatta University of Agriculture and Technology
Kenya
SLM specialist:
Kimengich Baobab
Jomo Kenyatta University of Agriculture and Technology
Kenya
SLM specialist:
Wamuongo Jane
Kenya Agricultural Research Institute
Kenya
SLM specialist:
Karanja Andrew
Kenya Agricultural Research Institute
Kenya
SLM specialist:
Namirembe Sara
World Agroforestry Centre
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
1.4 Declaration on sustainability of the described Technology
Is the Technology described here problematic with regard to land degradation, so that it cannot be declared a sustainable land management technology?
No
2. Description of the SLM Technology
2.1 Short description of the Technology
Definition of the Technology:
A hedgerow is a line of closely spaced shrubs and tree species, planted and trained to form a barrier or to mark the boundary of an area.
2.2 Detailed description of the Technology
Description:
A hedgerow may consist of a single species or several, typically mixed at random. In most newly planted British hedgerows, at least 60 percent of the shrubs are hawthorn, blackthorn, and (in the southwest) hazel, alone or in combination. The first two are particularly effective barriers to livestock. Other shrubs and trees used include holly, beech, oak, ash, and willow; the last three can become very tall.
Purpose of the Technology: Hedgerows have many values and functions. A diversity of hedgerow types and management on a farm is ideal. The functions of hedgerows include the following: Shelter - hedgerows provide protection for livestock and crops for up to thirty times their height, a dense base is also more effective. Flooding control –root systems of hedgerows regulate water movement and help prevent flooding. Disease control –hedgerows help prevent the spread of airborne disease. Water quality – hedgerows trap silt and soil particles, which clog up fish spawning grounds if they enter watercourses . Wildlife - hedgerows have become very important wildlife habitats in the countryside.
Establishment / maintenance activities and inputs: New hedges should be pruned from an early stage to establish a shape and prevent leggy, unhealthy growth. The amount pruned back will depend on the type of hedge. The hedge is shaped as early as possible and tapered so that it is wider at the bottom than the top, ensuring the lower part will get the sunlight it needs for healthy growth. Once the hedge is established, regular maintenance will ensure it keeps healthy and neat. The hedge is cut by the eye , but it can be a good idea to set lines with lengths of string taut between canes. If a formal hedge has got out of shape, cutting it back severely is often the only remedy. But this method is not suitable for all species. Conifers, in particular, react badly if you cut into old wood.
Natural / human environment: Hedgerows can be very effective at preventing loss of soil from fields, either through reducing wind erosion or through acting as a barrier to water-borne run-off. This is particularly so in arable areas, both where the land is flat and prone to wind-blow and in hilly areas where loss of soil following heavy rain can be a major problem especially in places prone to gully erosion.
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
Further specification of location:
Mbere South District
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)
Map
×2.7 Introduction of the Technology
Specify how the Technology was introduced:
- through land users' innovation
3. Classification of the SLM Technology
3.1 Main purpose(s) of the Technology
- reduce, prevent, restore land degradation
- reduce risk of disasters
3.2 Current land use type(s) where the Technology is applied
Cropland
- Tree and shrub cropping
Comments:
Major land use problems (compiler’s opinion): High soil erosion due to both wind and runoff
Major land use problems (land users’ perception): Reduced fertility due to loss of top soil
Future (final) land use (after implementation of SLM Technology): Cropland: Ct: Tree and shrub cropping
3.3 Has land use changed due to the implementation of the Technology?
Has land use changed due to the implementation of the Technology?
- No (Continue with question 3.4)
3.4 Water supply
Water supply for the land on which the Technology is applied:
- mixed rainfed-irrigated
3.5 SLM group to which the Technology belongs
- windbreak/ shelterbelt
3.6 SLM measures comprising the Technology
agronomic measures
- A1: Vegetation/ soil cover
vegetative measures
- V1: Tree and shrub cover
Comments:
Type of vegetative measures: aligned: -contour
3.7 Main types of land degradation addressed by the Technology
soil erosion by water
- Wt: loss of topsoil/ surface erosion
Comments:
Main causes of degradation: soil management, land tenure
3.8 Prevention, reduction, or restoration of land degradation
Specify the goal of the Technology with regard to land degradation:
- prevent 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):
The drawing on the left hand side shows boundary hedgerows demarcating different pieces of land.
Location: Embu North District. Eastern
Date: 2012/11/12
Technical knowledge required for field staff / advisors: low
Technical knowledge required for land users: moderate
Main technical functions: increase in organic matter, increase in nutrient availability (supply, recycling,…)
Aligned: -contour
Vegetative material: T : trees / shrubs
Number of plants per (ha): 500
Vertical interval between rows / strips / blocks (m): 5
Spacing between rows / strips / blocks (m): 10
Vertical interval within rows / strips / blocks (m): 5
Width within rows / strips / blocks (m): 1
Author:
Paul Kahiga, 8444-00300 Nairobi Kenya
4.2 General information regarding the calculation of inputs and costs
other/ national currency (specify):
Kshs
If relevant, indicate exchange rate from USD to local currency (e.g. 1 USD = 79.9 Brazilian Real): 1 USD =:
100.0
Indicate average wage cost of hired labour per day:
500.00
4.3 Establishment activities
Activity | Timing (season) | |
---|---|---|
1. | establishing a contour | during land preparation |
2. | planting seedlings of caliandra | at the start of construction |
4.4 Costs and inputs needed for establishment
Specify input | Unit | Quantity | Costs per Unit | Total costs per input | % of costs borne by land users | |
---|---|---|---|---|---|---|
Labour | Labour | ha | 1.0 | 100.0 | 100.0 | 100.0 |
Equipment | Tools | ha | 1.0 | 20.0 | 20.0 | 100.0 |
Plant material | Seedlings | ha | 1.0 | 20.0 | 20.0 | 100.0 |
Total costs for establishment of the Technology | 140.0 | |||||
Total costs for establishment of the Technology in USD | 1.4 |
4.5 Maintenance/ recurrent activities
Activity | Timing/ frequency | |
---|---|---|
1. | prunning | often |
4.6 Costs and inputs needed for maintenance/ recurrent activities (per year)
Specify input | Unit | Quantity | Costs per Unit | Total costs per input | % of costs borne by land users | |
---|---|---|---|---|---|---|
Labour | Labour | ha | 1.0 | 30.0 | 30.0 | 100.0 |
Equipment | Tools | ha | 1.0 | 20.0 | 20.0 | 100.0 |
Plant material | Seedlings | ha | 1.0 | 10.0 | 10.0 | 100.0 |
Total costs for maintenance of the Technology | 60.0 | |||||
Total costs for maintenance of the Technology in USD | 0.6 |
4.7 Most important factors affecting the costs
Describe the most determinate factors affecting the costs:
labour
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
- sub-humid
Thermal climate class: subtropics
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):
- medium (loamy, silty)
Topsoil organic matter:
- medium (1-3%)
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: Medium
Soil drainage/infiltration: Good
Soil water storage capacity: High
5.4 Water availability and quality
Ground water table:
5-50 m
Availability of surface water:
good
Water quality (untreated):
good drinking water
5.5 Biodiversity
Species diversity:
- medium
5.6 Characteristics of land users applying the Technology
Market orientation of production system:
- mixed (subsistence/ commercial)
Off-farm income:
- less than 10% of all income
Relative level of wealth:
- average
Individuals or groups:
- individual/ household
Level of mechanization:
- manual work
Gender:
- women
- men
Indicate other relevant characteristics of the land users:
Land users applying the Technology are mainly common / average land users
Population density: 10-50 persons/km2
Annual population growth: 0.5% - 1%
5.7 Average area of land used by land users applying the Technology
- < 0.5 ha
- 0.5-1 ha
- 1-2 ha
- 2-5 ha
- 5-15 ha
- 15-50 ha
- 50-100 ha
- 100-500 ha
- 500-1,000 ha
- 1,000-10,000 ha
- > 10,000 ha
Is this considered small-, medium- or large-scale (referring to local context)?
- small-scale
5.8 Land ownership, land use rights, and water use rights
Land ownership:
- individual, titled
Land use rights:
- individual
Water use rights:
- individual
5.9 Access to services and infrastructure
health:
- poor
- moderate
- good
education:
- poor
- moderate
- good
6. Impacts and concluding statements
6.1 On-site impacts the Technology has shown
Socio-economic impacts
Production
crop production
fodder production
fodder quality
animal production
production area
land management
Socio-cultural impacts
SLM/ land degradation knowledge
Improved livelihoods and human well-being
Ecological impacts
Water cycle/ runoff
surface runoff
Soil
nutrient cycling/ recharge
Biodiversity: vegetation, animals
pest/ disease control
6.2 Off-site impacts the Technology has shown
downstream siltation
6.3 Exposure and sensitivity of the Technology to gradual climate change and climate-related extremes/ disasters (as perceived by land users)
Gradual climate change
Gradual climate change
Season | increase or decrease | How does the Technology cope with it? | |
---|---|---|---|
annual temperature | increase | well |
6.4 Cost-benefit analysis
How do the benefits compare with the establishment costs (from land users’ perspective)?
Short-term returns:
positive
Long-term returns:
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
Comments:
There is a moderate trend towards spontaneous 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 |
---|
Hedgerows prevents or cuts down wind speed, which prevents erosion |
Hedgerows can act as barriers to windborne pests, and insects in the hedgerow pollinate crops, particularly bumblebees which need hedge banks. |
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? |
---|---|
Hinder machine operation within the farms | Have designated paths where machines can close |
Hedgerows can shelter pests, such as rabbits, which can damage crops. | Random inspection if they are sheltering pests and appropriate actions to be taken |
Shading of the crop can cause uneven ripening and disease | Periodic trimming to prevent excess shading |
7. References and links
7.1 Methods/ sources of information
- field visits, field surveys
- interviews with land users
When were the data compiled (in the field)?
18/09/2012
Links and modules
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Modules
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