Improved trash lines [Uganda]

Emikikizo (Lukiga)

technologies_990 - Uganda

Completeness: 71%

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:

Miiro Henry Dan

Ministry of agriculture animal industry and fisheries - Uganda


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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)

Promoting farmer innovation

Promoting farmer innovation [Uganda]

Identification of farmer innovators in SWC and water harvesting, and using them as focal points for visits from other farmers to spread the practices and stimulate the process of innovation.

  • Compiler: Kithinji Mutunga

2. Description of the SLM Technology

2.1 Short description of the Technology

Definition of the Technology:

Weeds and crop residues laid in bands across the slope of annual crop fields to conserve soil and water, and to incorporate organic matter into the soil after decomposition.

2.2 Detailed description of the Technology


Trash lines of organic material across the slope constitute a traditional land husbandry practice in south-west Uganda. These traditional, ‘unimproved’, trash lines are beneficial, but even better is an improved version designed through Participatory Technology Development (PTD). Improved trash lines are smaller, closer spaced, and of longer duration than the traditional type. They are more effective in controlling runoff and maintaining soil fertility.
All trash lines (improved and traditional) are composed of cereal stover (straw) and weeds that are collected during primary cultivation (hand hoeing), and heaped in strips along the approximate contour. Creeping grasses should not be used in trash lines: they can alternatively be decomposed in bundles, and then used as mulch in nearby banana plantations. Trash lines are used in hillside fields where annual crops, including sorghum, finger millet, beans and peas, are grown. The recommended spacing between the improved trash lines is 5-10 m, depending
on the slope: the steeper the closer. The amount of material available determines the cross section of each trash line (typically ±0.5 m wide and ±0.3 m high). Improved trash lines are left in place for four seasons (there are two seasons a year in Kabale) before they are dug into the soil. Much of the material used has, by this time, decomposed or been eaten by termites. Through incorporation into the topsoil, they improve soil fertility acting effectively as ‘mobile compost strips’. New trash lines are then established between the sites of the former lines. Upkeep comprises removal of weeds that sprout within the lines - before they set seed - and the addition of more trash during each new cultivation and weeding cycle.
Improved trash lines are multipurpose in retarding dispersed runoff while, as discussed, maintaining soil fertility. They are a low-cost option for soil and water conservation. However, they need to be complemented by other measures on the steeper slopes. The climate in this part of Uganda is subhumid, with a bimodal rainfall regime, and average annual rainfall of around 800 mm. Hill tops are used for grazing, the lower slopes are cultivated with annual crops (where the trash lines are found) and the valleys are dedicated to bananas and other cash crops. Families are large: 8-10 persons, and the population density is high, at nearly 200 persons/km2.

2.3 Photos of the Technology

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:

Kabale district

Specify the spread of the Technology:
  • evenly spread over an area
If precise area is not known, indicate approximate area covered:
  • 0.1-1 km2

Total area covered by the SLM Technology is 0.25 km2.

it is an indeginous technology. Widely used in various fields and at different slopes.

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)

3. Classification of the SLM Technology

3.1 Main purpose(s) of the Technology

  • improve production
  • reduce, prevent, restore land degradation
  • adapt to climate change/ extremes and its impacts

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



  • Annual cropping
  • Perennial (non-woody) cropping
  • Tree and shrub cropping
Annual cropping - Specify crops:
  • cereals - millet
  • cereals - sorghum
  • legumes and pulses - beans
  • legumes and pulses - peas
Perennial (non-woody) cropping - Specify crops:
  • banana/plantain/abaca
  • Eucalyptus
Number of growing seasons per year:
  • 2

Longest growing period in days: 180 Longest growing period from month to month: Feb - Jul Second longest growing period in days: 120 Second longest growing period from month to month: Sep - Jan


Major land use problems (compiler’s opinion): Continuous cultivation of annual crops on slopes prone to erosion, with little or no restitution of fertility through manures
or fertilizers.

Major land use problems (land users’ perception): continous cultivation without fallow due to small sizes of farms

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
  • cross-slope measure
  • water harvesting

3.6 SLM measures comprising the Technology

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, Cn: fertility decline and reduced organic matter content

Main causes of degradation: other human induced causes (specify) (lack of communication), education, access to knowledge and support services (lack of spread of knowledge)

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

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Technical specifications (related to technical drawing):

Trash lines without crops (left)
and with crops (beans; right).
The insert shows the stages of the technology: regularly spaced trash lines are kept place for four seasons (1); then decompose over time and are incorporated into the soil (2); and finally new trash lines are placed between the previous strips (3).

Technical knowledge required for field staff / advisors: low

Technical knowledge required for land users: low

Main technical functions: control of dispersed runoff: impede / retard, increase of infiltration, increase in soil fertility

Secondary technical functions: control of dispersed runoff: retain / trap, increase in organic matter, improvement of soil structure, sediment harvesting

Agronomic measure: mulching, trash lines
Material/ species: weed residue, sorghum
Remarks: along contour


Mats Gurtner

4.2 General information regarding the calculation of inputs and costs

other/ national currency (specify):

Uganda Shillings

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:


4.4 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 25.0 25.0 100.0
Equipment Tools ha 1.0 5.0 5.0 100.0
Total costs for establishment of the Technology 30.0
Total costs for establishment of the Technology in USD 0.03

Duration of establishment phase: 36 month(s)

4.5 Maintenance/ recurrent activities

Activity Timing/ frequency
1. During land cultivation, existing (old) trash lines are dug. 2. New trash lines are then created exactly between the (cross-slope) Dry season / each cropping season
2. The size of the trash lines depends on the amount of trash available, Dry season
3. Weeds are added to the trash lines, and, in preparation for the second Second season
4. Trash lines are kept free of growing weeds and built up with more Third and fourth seasons
5. Trash lines are kept free of growing weeds and built up with moretrash. Full cycle for improved trash lines: 4 seasons (2 years)

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


Machinery/ tools: hand hoe

These figures are approximate, representing a typical situation with 1,500 running metres of improved trash lines, per hectare, at a spacing of 7 m apart on a 10% slope. The 1st year (first and second seasons) involves more work than the
2nd year (third and fourth seasons): the figure given is an annual average of all work associated with trash lines. The costs of the traditional, larger and wider spaced trash lines are about 50% more than these given above - because trash has to be carried further.

4.7 Most important factors affecting the costs

Describe the most determinate factors affecting the costs:

Labour, need to collect and heap the trashlines material in lines above the slope

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
Specify average annual rainfall (if known), in mm:


Agro-climatic zone
  • sub-humid

Thermal climate class: tropics

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.
Comments and further specifications on topography:

Slopes on average: Also rolling and hilling (both ranked 2)

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%)
  • 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 texture: Medium (the trash material modifies the organic matter content of the areas applied)
Soil fertility: Medium (ranked 1) and low (ranked 2)
Soil drainage/infiltration: Medium
Soil water storage capacity: Low (ranked 1) and medium (ranked 2)

5.6 Characteristics of land users applying the Technology

Market orientation of production system:
  • subsistence (self-supply)
  • mixed (subsistence/ commercial)
Off-farm income:
  • 10-50% of all income
Relative level of wealth:
  • poor
  • average
Level of mechanization:
  • manual work
Indicate other relevant characteristics of the land users:

1% of the land users are very rich and own 5% of the land.
5% of the land users are rich and own 10% of the land.
24% of the land users are average wealthy and own 50% of the land.
55% of the land users are poor and own 25% of the land.

Off-farm income specification: some farmers are involved in trade with nearby Rwanda and there are also a number of families who receive remittances from family members who work in Kabale or as far away as Kampala

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

Average area of land owned or leased by land users applying the Technology: Also 1-2 ha (ranked 2) and 2-5 ha (ranked 3)

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

Land ownership:
  • individual, not titled
Land use rights:
  • communal (organized)
  • individual

6. Impacts and concluding statements

6.4 Cost-benefit analysis

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


Long-term returns:

very positive

6.5 Adoption of the Technology


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: the technology is indeginous. There is some evidence of growing spontaneous adoption.

6.7 Strengths/ advantages/ opportunities of the Technology

Strengths/ advantages/ opportunities in the land user’s view
Improved trash lines have small but significant advantages over the traditional trash lines (which are beneficial themselves) in terms of (a) less labour (b) improved crop performance

How can they be sustained / enhanced? Continue with farmer-to-farmer visits for this to be explained.
Strengths/ advantages/ opportunities in the compiler’s or other key resource person’s view
The technology is very simple and uses locally available material. It is easy to understand, being a modification of an existing tradition

How can they be sustained / enhanced? Continue with farmer-to-farmer visits for first hand learning.
Multiple ecological and SWC benefits: improves soil fertility, reduces erosion, increases infiltration etc

How can they be sustained / enhanced? Continue to encourage adoption of (and further farmer experimentation with) the improved trash lines.

6.8 Weaknesses/ disadvantages/ risks of the Technology and ways of overcoming them

Weaknesses/ disadvantages/ risks in the land user’s view How can they be overcome?
Source of weeds Pull out weeds before they set seed and don’t use stoloniferous or rhizome-forming (creeping) grasses in trash lines (see picture).
trash line harbours pest and diseases use entirely dry grass or material
Weaknesses/ disadvantages/ risks in the compiler’s or other key resource person’s view How can they be overcome?
Where land is limiting, agricultural land which would be used, is lost uses it as a crop rotation basis
The trash lines are not enough on their own to control erosion on the steeper slopes Introduce/promote supplementary structural remedies such as earth bunds.
Competition for crop residues which have an alternative use as livestock fodder and, especially, mulch in banana plantations Grow hedgerows of shrubs/grasses to increase availability of material for fodder, trash lines and mulching.

7. References and links

7.1 Methods/ sources of information

7.2 References to available publications

Title, author, year, ISBN:

Briggs SR et al. Livelihoods in Kamwezi, Kabale District, Uganda.. 1998.

Available from where? Costs?

Silsoe Research Institute, UK

Title, author, year, ISBN:

Mutunga K and Critchley W. Farmer’s initiatives in land husbandry Technical Report No 27. 2001.

Available from where? Costs?

Regional Land Management Unit, Nairobi, Kenya

Title, author, year, ISBN:

Critchley W and Mutunga K .Local innovation in a global context: documenting farmer initiatives in land husbandry through WOCAT Land Degradation and Development (14) pp 143–162. 2003.

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