Trenches [Uganda]


technologies_1561 - Uganda

Completeness: 65%

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:

Mugabe Albert

Ntungamo District


SLM specialist:

Mazimakwo Kukundakwe

Kabale District


SLM specialist:

Pollina Elijah

Rwerazi matooke group association


Name of project which facilitated the documentation/ evaluation of the Technology (if relevant)
The Transboundary Agro-ecosystem Management Project for the Kagera River Basin (GEF-FAO / Kagera TAMP )
Name of the institution(s) which facilitated the documentation/ evaluation of the Technology (if relevant)
Food and Agriculture Organization (FAO) - Italy
Name of the institution(s) which facilitated the documentation/ evaluation of the Technology (if relevant)
Rwerazi matooke group association - Uganda

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:


1.5 Reference to Questionnaire(s) on SLM Approaches (documented using WOCAT)

Construction of trenches in cropland.

Construction of trenches in cropland. [Uganda]

Farmer field facilitators mobilized and sensitized the land users on the need to control soil erosion in banana plantations and to conserve moisture in the soil.

  • Compiler: Wilson Bamwerinde

2. Description of the SLM Technology

2.1 Short description of the Technology

Definition of the Technology:

Digging trenches on a gentle slope in banana plantation in Rwerazi.

2.2 Detailed description of the Technology


Trenches dug at 2 ft. wide and 20m long in a banana plantation . Twelve trenches at a distance of 10m each in about 7 acres to control water runoff and soil erosion.

Purpose of the Technology: Trenches to contain and collect heavy water runoff. To reduce loss of top soil and increase soil fertility for perennial crops, thus increasing productivity.

Establishment / maintenance activities and inputs: Kagera TAMP initiative for the use of trenches by land users of Rwerazi matoke association , with hoes, spades, pangas digging trenches of 2ft deep , 2.5 ft wide and 20m long at a space of 10m in a banana planation.

The trenches are of 2 types, Fanya juu and Fanya kin.

Natural / human environment: The area is gentle sloping susceptible to water runoff leading to enough loam sopils in in good banana planation.

2.5 Country/ region/ locations where the Technology has been applied and which are covered by this assessment



Region/ State/ Province:


Further specification of location:


Specify the spread of the Technology:
  • evenly spread over an area
If precise area is not known, indicate approximate area covered:
  • 1-10 km2

Total area covered by the SLM Technology is 2 km2.

The technology is practiced in Rwerazi and Kitwe town council among farmer field school members in those localities.

2.6 Date of implementation

If precise year is not known, indicate approximate date:
  • 10-50 years ago

2.7 Introduction of the Technology

Specify how the Technology was introduced:
  • through projects/ external interventions
Comments (type of project, etc.):

-Introduced through UNIFA & FAO Kagera /TAMP projects.
-Training in use of trenches in 1991 and group cohesion in 1995.

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



  • Annual cropping
  • Perennial (non-woody) cropping
Perennial (non-woody) cropping - Specify crops:
  • banana/plantain/abaca
Number of growing seasons per year:
  • 2

Longest growing period in days: 150 Longest growing period from month to month: September to December.Second longest growing period in days: 90 Second longest growing period from month to month: March to May.


Major land use problems (compiler’s opinion): Increased runoff and lack of soil and water conservation would lead to loss of productive top soil, desertification leading to soil infertility and climatic change.

Type of cropping system and major crops comments: Technology is effective in banana plantation.

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

  • cross-slope measure

3.6 SLM measures comprising the Technology

structural measures

structural measures

  • S3: Graded ditches, channels, waterways
  • S4: Level ditches, pits

Main measures: structural measures

3.7 Main types of land degradation addressed by the Technology

soil erosion by water

soil erosion by water

  • Wt: loss of topsoil/ surface erosion
chemical soil deterioration

chemical soil deterioration

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

water degradation

  • Ha: aridification

Main type of degradation addressed: Wt: loss of topsoil / surface erosion

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

Main causes of degradation: soil management (To prevent degradation of land & water banana planation.)

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

Main goals: mitigation / reduction of land degradation

Secondary goals: prevention of land degradation

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

4.1 Technical drawing of the Technology

Technical specifications (related to technical drawing):

Technical knowledge required for field staff / advisors: high (Technical person needs to demonstrate the technology.)

Technical knowledge required for land users: moderate

Main technical functions: control of dispersed runoff: impede / retard

Secondary technical functions: control of concentrated runoff: retain / trap, increase / maintain water stored in soil

Structural measure: Trenches
Vertical interval between structures (m): N/A
Spacing between structures (m): 10
Depth of ditches/pits/dams (m): 0.6
Width of ditches/pits/dams (m): 0.76
Length of ditches/pits/dams (m): 6.09
Height of bunds/banks/others (m): N/A
Width of bunds/banks/others (m): N/A
Length of bunds/banks/others (m): N/A

Construction material (earth): Digging a trench on earth surface.

4.2 General information regarding the calculation of inputs and costs

other/ national currency (specify):


If relevant, indicate exchange rate from USD to local currency (e.g. 1 USD = 79.9 Brazilian Real): 1 USD =:


Indicate average wage cost of hired labour per day:


4.3 Establishment activities

Activity Timing (season)
1. Digging trenches 2012 September

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 92.3 92.3 100.0
Equipment Tools ha 1.0 9.4 9.4
Total costs for establishment of the Technology 101.7
Total costs for establishment of the Technology in USD 0.04

Duration of establishment phase: 1 month(s)

4.5 Maintenance/ recurrent activities

Activity Timing/ frequency
1. Digging trenches April 2012

The land user does not meet the maintenance costs of old existing trenches but establishes /digs new trenches after every 2 years when the old trenches are filled with silt. He believes that old filled trenches should not be worked upon as they are filled with manure and nutrients. By digging new trenches ,the land user meets the new establishment and construction costs.

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 15.3 15.3
Total costs for maintenance of the Technology 15.3
Total costs for maintenance of the Technology in USD 0.01

Machinery/ tools: Hoes,spades, pick axe are used to construct and maintain the trenches.

The costs are the total costs for construction and maintenance of the technology for each land user for area of about 1 ha and were estimated as of 19/04/2013.

4.7 Most important factors affecting the costs

Describe the most determinate factors affecting the costs:

-Human labor is scarce.
-High cost of labor.
-Land users require constant monitoring & mobilization.

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
Specifications/ comments on rainfall:

Rainy season . September to December & March to May.

Agro-climatic zone
  • sub-humid

Thermal climate class: tropics. Tropics (Temperature mean annual of 18°C to 24°C)
Bi-modal rainfall. 180-269 days.

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%)
  • 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.
Indicate if the Technology is specifically applied in:
  • concave situations
Comments and further specifications on topography:

Altitudinal zone: The technology is carried out in areas of 1000 to 1500 m.a.s.l.
Slopes on average: Gentle (The technology is appropriate in gentle sloping areas)

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:
  • poor
  • average
Individuals or groups:
  • individual/ household
Level of mechanization:
  • manual work
  • women
  • men
Indicate other relevant characteristics of the land users:

Population density: 100-200 persons/km2
Annual population growth: 2% - 3%
30% of the land users are rich (Income records 1,750,000 shs monthly.).
40% of the land users are average wealthy (average monthly income of less than 1,000,000shs).
30% of the land users are poor.

Off-farm income specification: most land users' income is from farm.
Level of mechanization: Manual work (family and hired casual labour depending on season)
Market orientation: Mixed (300 bunches sold, 30 eaten monthly on average)

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

On average households have medium sized banana plantation.

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

Land ownership:
  • individual, not titled
Land use rights:
  • individual
Water use rights:
  • individual

Land inherited untitled land from his father and others have individual and freehold.

5.9 Access to services and infrastructure

  • poor
  • moderate
  • good
  • poor
  • moderate
  • good
technical assistance:
  • poor
  • moderate
  • good
  • poor
  • moderate
  • good
drinking water and sanitation:
  • poor
  • moderate
  • good
financial services:
  • poor
  • moderate
  • good

6. Impacts and concluding statements

6.1 On-site impacts the Technology has shown

Socio-economic impacts


crop production

Quantity before SLM:


Comments/ specify:

30 to 50kg/bunch of banana.

Income and costs

expenses on agricultural inputs




Socio-cultural impacts

food security/ self-sufficiency

Quantity before SLM:


Comments/ specify:

increase in banana bunch size.

conflict mitigation


Improved livelihoods and human well-being

Comments/ specify:

The land users have permanent houses and a car as the technology has improved household through improved production and income.

Ecological impacts

Water cycle/ runoff

surface runoff


excess water drainage


groundwater table/ aquifer


soil moisture


soil loss


6.4 Cost-benefit analysis

How do the benefits compare with the establishment costs (from land users’ perspective)?
Long-term returns:


How do the benefits compare with the maintenance/ recurrent costs (from land users' perspective)?
Short-term returns:



Land users have had increased banana bunch size and improved quality

6.5 Adoption of the Technology


Comments on acceptance with external material support: Some land users got external assistance ,others individually implemented the activity.

20% of land user families have adopted the Technology without any external material support

Comments on spontaneous adoption: 20% of land users in Rwerazi matooke group voluntarily implement the technology . 66.7% are not implementing the technology.

There is a moderate trend towards spontaneous adoption of the Technology

Comments on adoption trend: As most of land users still lack some of the inputs and material support.

6.7 Strengths/ advantages/ opportunities of the Technology

Strengths/ advantages/ opportunities in the land user’s view
It increases productivity.

How can they be sustained / enhanced? Regulates maintenance of trenches.
It maintains manure in the banana plantation.

How can they be sustained / enhanced? Regular maintenance of trenches.
Strengths/ advantages/ opportunities in the compiler’s or other key resource person’s view
It control water runoff.

How can they be sustained / enhanced? By digging and repairing the trenches regularly.
Stores water which slowly seeps in the soil.

How can they be sustained / enhanced? By digging and repairing the trenches regularly.

7. References and links

7.1 Methods/ sources of information

Links and modules

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