Technologies

Runoff/floodwater farming [Ethiopia]

Korbe (Oromifa)

technologies_943 - Ethiopia

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:
SLM specialist:
Name of project which facilitated the documentation/ evaluation of the Technology (if relevant)
Book project: SLM in Practice - Guidelines and Best Practices for Sub-Saharan Africa (SLM in Practice)
Name of project which facilitated the documentation/ evaluation of the Technology (if relevant)
Book project: Water Harvesting – Guidelines to Good Practice (Water Harvesting)
Name of the institution(s) which facilitated the documentation/ evaluation of the Technology (if relevant)
FAO (FAO) - Italy
Name of the institution(s) which facilitated the documentation/ evaluation of the Technology (if relevant)
Ministry of Agriculture and Rural Development (Ministry of Agriculture and Rural Development) - Ethiopia

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:

Runoff/flood farming locally known as Korbe is a practice that involves diversion of water from different sources for growing vegetables, fruit trees and crops of high value on a land prepared known as Korbe.

2.2 Detailed description of the Technology

Description:

Runoff and floodwater farming is a traditionally practiced water harvesting system which helps overcome problems of soil moisture and crop failure in a hot, dry area with erratic rainfall and shallow, highly erodible soils: Flood water and runoff from ephemeral rivers, roads and hillsides is captured through temporary stone and earth embankments. A system of hand dug canals – consisting of a main diversion canal and secondary / tertiary canals – conveys and distributes the captured water to the cultivated fields in naturally flat or leveled areas. The total length of the canal system is 200 – 2000 m. The harvested water is used for growing high value crops, vegetables and fruit trees. Irrigated fields are divided into rectangular basins bordered by ridges to maximize water storage and minimize erosion risk.

Runoff and floodwater management requires preparedness for immediate action by the farmers: When a flood is expected in the ephemeral river, farmers rush to the diversion site and start erecting the embankment across the bed of the stream. Similarly, each famer starts to maintain the canal which leads water to his field. A schedule defines the date and time each farmer is allocated his turn to irrigate. When the water reaches the field, it is spread either through flooding or distributed in furrows which are opened and closed using a local tool.

The ratio between catchment area and production area is 10:1 – 100:1 or greater. While the diversion canals / ditches and basins for tree planting are permanent structures, basins for annual crops are seasonal. Soil fertility is improved by additional measures such as composting and mulching. Maintenance, including repairs to breaks along the canal and water conveying ditches, is needed every season before the onset of rains.

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:

Ethiopia

Further specification of location:

Harea, Delo Belina, Bishan Bahe

Specify the spread of the Technology:
  • evenly spread over an area
If precise area is not known, indicate approximate area covered:
  • 10-100 km2
Comments:

Runoff or flood water diversion is a very common farming practice in Dire Dawa and the surrounding areas. Runoff and flood water from ephemeral rivers, road discharges and runoff from hillsides is diverted for supplimented irrigation in to cultivated fields. Cultivated fields are prepared in rectangular blocks, which are leveled and shaped such that maximum retention and cupturing of the water is possible. Korbe is very suitable for horticultural, fruit trees and high value crop production.

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.):

The technology evolved locally to address water shortages for crop production and reduce the top soil movement by runoff. At present improved techniques of constructing diversion ditches and efficient techniques for preparing Korbe have been included.

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

Land use mixed within the same land unit:

Yes

Specify mixed land use (crops/ grazing/ trees):
  • Agro-silvopastoralism

Cropland

Cropland

  • Annual cropping
  • Tree and shrub cropping
Annual cropping - Specify crops:
  • cereals - oats
  • cereals - sorghum
  • root/tuber crops - sweet potatoes, yams, taro/cocoyam, other
  • Chat (khat, shrub)
Number of growing seasons per year:
  • 1
Specify:

Longest growing period in days: 210 Longest growing period from month to month: Apr - Nov

Grazing land

Grazing land

Comments:

Major land use problems (compiler’s opinion): Overgrazing on hillslopes causing severe degradation, human and livestock interferences in area enclosures, use of crop varities of low production.

Major land use problems (land users’ perception): Low fertility of soils and the associated decline in productionn and erratic rains

Other grazingland: open grazing

Other grazingland: stall-feeding

Type of cropping system and major crops comments: Sorghum - Sweet potato; Chat - Sorgum - Sweet potato

Major food crop annual cropping: Sorghum
Major cash crop tree and shrub cropping: Chat (ranked 1) and fruit trees (ranked 2)

3.4 Water supply

Water supply for the land on which the Technology is applied:
  • rainfed
Comments:

Water supply: Also post-flooding

3.5 SLM group to which the Technology belongs

  • improved ground/ vegetation cover
  • cross-slope measure
  • irrigation management (incl. water supply, drainage)

3.6 SLM measures comprising the Technology

vegetative measures

vegetative measures

  • V1: Tree and shrub cover
structural measures

structural measures

  • S3: Graded ditches, channels, waterways
Comments:

Main measures: vegetative measures, structural measures

Secondary measures: agronomic measures

Type of agronomic measures: early planting, mixed cropping / intercropping, mulching, legume inter-planting, contour ridging

Type of vegetative measures: aligned: -contour, aligned: -graded strips *<sup>3</sup>, in blocks

3.7 Main types of land degradation addressed by the Technology

soil erosion by water

soil erosion by water

  • Wr: riverbank erosion
chemical soil deterioration

chemical soil deterioration

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

Main type of degradation addressed: Cn: fertility decline and reduced organic matter content

Secondary types of degradation addressed: Wr: riverbank erosion

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):

Technical knowledge required for field staff / advisors: moderate

Technical knowledge required for land users: moderate

Main technical functions: reduction of slope angle, water harvesting / increase water supply

Secondary technical functions: control of dispersed runoff: retain / trap, increase of infiltration, water spreading, increase in soil fertility

Early planting
Material/ species: vegetables
Quantity/ density: 0.20x0.20
Remarks: nearly contour

Mixed cropping / intercropping
Material/ species: cabbage and pepper
Quantity/ density: 0.20x0.15
Remarks: on the ridge

Mulching
Material/ species: Residue

Contour ridging
Remarks: ridge + basin

Aligned: -contour
Vegetative material: F : fruit trees / shrubs, C : perennial crops
Vertical interval between rows / strips / blocks (m): 0.20-0.50
Spacing between rows / strips / blocks (m): 0.30-0.50
Width within rows / strips / blocks (m): 1.80-3.80

Aligned: -graded strips
Vegetative material: O : other

In blocks
Vegetative material: F : fruit trees / shrubs, O : other
Number of plants per (ha): 400-1000
Vertical interval between rows / strips / blocks (m): 0.30
Spacing between rows / strips / blocks (m): 4x4

Vegetative measure: in blocks
Vegetative material: C : perennial crops
Number of plants per (ha): 1500-3000
Vertical interval between rows / strips / blocks (m): 0.1
Spacing between rows / strips / blocks (m): 2x4

Vegetative measure: Vegetative material: C : perennial crops

Vegetative measure: Vegetative material: C : perennial crops

Vegetative measure: Vegetative material: C : perennial crops

Fruit trees / shrubs species: Guava, papaya and mango

Perennial crops species: Chat and coffee

Slope (which determines the spacing indicated above): 3.00%

If the original slope has changed as a result of the Technology, the slope today is (see figure below): 1.00%

Gradient along the rows / strips: 0.00%

Reshaping surface
Vertical interval between structures (m): 0.3-0.5
Spacing between structures (m): 3-4
Depth of ditches/pits/dams (m): 0.2-0.3
Width of ditches/pits/dams (m): 0.3
Height of bunds/banks/others (m): 0.25
Width of bunds/banks/others (m): 0.5

Structural measure: diversion ditch / cut-off drain
Depth of ditches/pits/dams (m): 0.3-0.5
Width of ditches/pits/dams (m): 1-3
Length of ditches/pits/dams (m): 500-2000
Height of bunds/banks/others (m): 0.30
Width of bunds/banks/others (m): 1-2

Construction material (earth): blocks, ridges and furrow

Construction material (stone): the diversion ditch

Slope (which determines the spacing indicated above): 3%

If the original slope has changed as a result of the Technology, the slope today is: 1%

Lateral gradient along the structure: 0%

For water harvesting: the ratio between the area where the harvested water is applied and the total area from which water is collected is: 1:100

4.2 General information regarding the calculation of inputs and costs

other/ national currency (specify):

ETH Birr

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

8.5

Indicate average wage cost of hired labour per day:

0.85

4.3 Establishment activities

Activity Timing (season)
1. Land preparation/tillage/harrowing Dry season
2. Planting Onset of rains
3. Weeding and cultivation During rains
4. Manuring Retrait des pluies
5. Mulching Withdrawal of rains
6. Clearing Dry season
7. Ploughing and harrowing Dry season
8. Construction of field ditches Before the on set of rains
9. Constructing temporary head work for diversion Dry season
10. Construction of blocks, ridge and basins Onset of rains

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 1.0 253.0 253.0 100.0
Equipment Tools ha 1.0 24.0 24.0 100.0
Plant material Seeds ha 1.0 106.0 106.0 100.0
Total costs for establishment of the Technology 383.0
Total costs for establishment of the Technology in USD 45.06
Comments:

Duration of establishment phase: 30 month(s)

4.5 Maintenance/ recurrent activities

Activity Timing/ frequency
1. First tillage Dry season / each cropping season
2. Second tillage Dry season / each cropping season
3. Ridge basin formation Onset of rains / each cropping season
4. Planting Early rains / annual
5. Weeding & cultivation During rains / growimg period
6. Land fertilizing During rains / before sowing
7. Repair of blocks Dry season /1-2
8. Repair of diversion canals Dry season /1-2
9. Planting and replanting After rain /1-2
10. Maintaining of fence Dry season /1
11. Repair breaks in diversion canal Before onset of rain/as needed
12. Maintain diversion head works Before onset of rain/1-2
13. Repair breaks on ridges and blocks Before onset of rain/1-2

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 1.0 450.0 450.0 100.0
Equipment Tools ha 1.0 64.0 64.0 100.0
Plant material Seeds ha 1.0 300.0 300.0 100.0
Total costs for maintenance of the Technology 814.0
Total costs for maintenance of the Technology in USD 95.76
Comments:

Machinery/ tools: Oxen plough, Dengora, Shovel

length of the diversion ditch and considering 0.5 ha of the land is planted by fruit trees and 0.5 ha planted with vegetables

4.7 Most important factors affecting the costs

Describe the most determinate factors affecting the costs:

labour required for the diversion ditch, block making and irrigation channels is high

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:

650.00

Specifications/ comments on rainfall:

Irrégulière, mal distribuée

Agro-climatic zone
  • semi-arid

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%)
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:
  • 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 fertility: Low (ranked 1), medium and very low (both ranked 2)
Soil drainage/infiltration: Good
Soil water storage capacity: Low (ranked 1), very low and medium (both ranked 2)

5.6 Characteristics of land users applying the Technology

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

Population density: 50-100 persons/km2
Annual population growth: 2% - 3%
40% of the land users are average wealthy.
40% of the land users are poor.
10% of the land users are poor.
Off-farm income specification: no big difference is observed between the average/better of and the poor in this regard.
Level of mechanization: Animal traction (gentle slopes are cultivated by animal traction, ranked 1) and manual work (steep slopes and land between narrow terraces are cultivated manual, ranked 2)
Market orientation: Subsistence (Sorgum for domestic use, ranked 1) and mixed (ranked 2)

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
Comments:

Land suitable to cultivation is very small while population growth is high

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

Land ownership:
  • state
Land use rights:
  • individual

6. Impacts and concluding statements

6.1 On-site impacts the Technology has shown

Socio-economic impacts

Production

crop production

decreased
increased
Comments/ specify:

Plus 200% de la valeur brute de la production après 3 ans, 400% après 10 ans

fodder production

decreased
increased
Comments/ specify:

From vegetables

fodder quality

decreased
increased
Comments/ specify:

From vegetables

wood production

decreased
increased

production area

decreased
increased
Comments/ specify:

à cause des structures de conservation

Income and costs

farm income

decreased
increased
Comments/ specify:

Bénéfice net 1ère année : 226 US$ ; à partir de la 4ème année : 711 US$

Socio-cultural impacts

community institutions

weakened
strengthened
Comments/ specify:

Group work enhanced, cooprative established

SLM/ land degradation knowledge

reduced
improved
Comments/ specify:

Better land management in place

conflict mitigation

worsened
improved

Ecological impacts

Water cycle/ runoff

surface runoff

increased
decreased
Quantity before SLM:

50

Quantity after SLM:

5

Comments/ specify:

De 50% à 5% des pluies annuelles

groundwater table/ aquifer

lowered
recharge
Soil

soil moisture

decreased
increased
Comments/ specify:

Due to structural measures

soil loss

increased
decreased
Comments/ specify:

De 60 à 6 t/ha

nutrient cycling/ recharge

decreased
increased
Other ecological impacts

Soil fertility

decreased
increased
Comments/ specify:

Due to manure and residue mulching

Infiltration

decreased
increased

6.2 Off-site impacts the Technology has shown

reliable and stable stream flows in dry season

reduced
increased

downstream flooding

increased
reduced

downstream siltation

increased
decreased

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

Climate-related extremes (disasters)

Meteorological disasters
How does the Technology cope with it?
local rainstorm not well
local windstorm well
Climatological disasters
How does the Technology cope with it?
drought well
Hydrological disasters
How does the Technology cope with it?
general (river) flood not well

Other climate-related consequences

Other climate-related consequences
How does the Technology cope with it?
reduced growing period 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:

very positive

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

very positive

Long-term returns:

very positive

Comments:

Le bénéfice net est positif à cause de l’augmentation rapide de la production

6.5 Adoption of the Technology

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 a moderate trend towards spontaneous adoption of the Technology

6.7 Strengths/ advantages/ opportunities of the Technology

Strengths/ advantages/ opportunities in the land user’s view
Increase the income of farmers (vegetables + fruits)

How can they be sustained / enhanced? more diversified fruit and vegetable varieties to be introduced.
Increase in productivity of land

How can they be sustained / enhanced? access to credit services
Strengths/ advantages/ opportunities in the compiler’s or other key resource person’s view
Enhancing of the rainfall multiplier effect

How can they be sustained / enhanced? frequent maintenance of the diversion ditches and field canals, blocks.
Good seed bed preparation enhancing germination and growth

How can they be sustained / enhanced? levelling of land to be further continued and enhanced.
Reduction of water losses by means of mulching

How can they be sustained / enhanced? effective mulching to reduce evapotranspiration should be strengthened
Facilitate formation of cooperatives and group work

How can they be sustained / enhanced? more coopratives established and strengthen their management systems
Performing timely activities in the appropriate time

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?
Lack of market Organize marketing outlets
Earily perishable Arrange proper storage system
Perte de terres (à cause des structures de conservation) compensée par le bénéfice de la production augmentée
Inaccessibilité des marchés
Weaknesses/ disadvantages/ risks in the compiler’s or other key resource person’s view How can they be overcome?
Increased labour constraints: construction of diversion ditches, preparation of irrigation basin and spreading the runoff water and regular maintenance / reconstruction of structures is very labour intensive providing improved farm tools could improve efficiency of operation, organising farmers in groups for sharing labor would curtail labor problems; Placing permanent structures at the iversion head (concrete) and paving ditches to improve
channel stability would reduce maintenance activities.
Social inequity: mainly better-off farmers apply the technology (due to high costs) providing credit solves financial problems and facilitating market
would motivate land users to get more engaged in the business.
Loss of land (through conservation structures is outweighed by the high production benefits.

7. References and links

7.2 References to available publications

Title, author, year, ISBN:

Danano D. 2008 (unpublished): Soil and Water Conservation Practices for Sustainable Land Management in Ethiopia. Ethiocat.

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