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

Name of project which facilitated the documentation/ evaluation of the Technology (if relevant)

DESIRE (EU-DES!RE)

Name of the institution(s) which facilitated the documentation/ evaluation of the Technology (if relevant)

INIDA (INIDA) - Cape Verde

1.3 Conditions regarding the use of data documented through WOCAT

When were the data compiled (in the field)?

05/03/2009

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

Yes

1.5 Reference to Questionnaire(s) on SLM Approaches

2.1 Short description of the Technology

Definition of the Technology:

It is a technique which uses the structure of a cross-slope barrier of Aloe vera to combat soil erosion by decreasing surface wash and increasing infiltration.

2.2 Detailed description of the Technology

Description:

Aloe vera is a durable herbaceous plant which is planted in the form of living barriers to recover degraded slopes on the Cape Verde Islands.

Purpose of the Technology: The plants are closely planted along the contour to build an efficient barrier for retention of eroded sediments and superficial runoff. The living hedges of Aloe vera stabilize the soil, increase soil humidity by improving infiltration and soil structure. Groundwater is recharged indirectly. Soil cover is improved, and thus evaporation and erosion reduced.

Establishment / maintenance activities and inputs: Implementation is relatively simple. The contour lines are demarcated using a water level. Seedlings are planted along one line at a distance of 30-50 cm between plants; spacing between the rows varies between 3-5 m according to the slope. The technology is applied in subhumid and semi-arid areas, on steep slopes with shallow soils, a poor vegetation cover and high soil erosion rates. These areas are generally used by poor subsistence farmers for rainfed agriculture with crops such as maize and beans, which are considered inappropriate for such slope angles. On slopes steeper than 30% the living barriers are often combined with stone walls (width 40-50 cm; height 80-90 cm). The plants stabilize the stone risers, making this combined technology one of the most efficient measures for soil erosion control on the Cape Verde Islands.

Natural / human environment: The herbaceous plant is well adapted to the local biophysical conditions and to the land use system: it can be grown with any crop, is available for any farmer, establishment and transport are simple, its green leaves are not palatable for livestock, the plant is extremely resistant to water stress and grows on any bioclimatic zone on the island. Furthermore, Aloe is known for its multiple uses in traditional medicine.

2.3 Photos of the Technology

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

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

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

Comments:

Major land use problems (compiler’s opinion): Low productive land, shallow soil depth, loss of soil by runoff water, reducing its thickness and fertility

Major land use problems (land users’ perception): Low productive land, weak and thin

Semi-nomadism / pastoralism: Especially for goats

Cut-and-carry/ zero grazing: Feeding of cattle

Livestock is grazing on crop residues

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:

• 1

Specify:

Longest growing period in days: 90; Longest growing period from month to month: August to October

3.4 SLM group to which the Technology belongs

• cross-slope measure

3.5 Spread of the Technology

Specify the spread of the Technology:

• applied at specific points/ concentrated on a small area

Comments:

Total area covered by the SLM Technology is 71.5 km2.

3.6 SLM measures comprising the Technology

Comments:

Type of vegetative measures: aligned: -contour

3.7 Main types of land degradation addressed by the Technology

Comments:

Secondary types of degradation addressed: Bc: reduction of vegetation cover, Ha: aridification, Hs: change in quantity of surface water

Main causes of degradation: soil management (cultivation of maize in much sloping land), overgrazing, droughts (Cyclical droughts), other natural causes (avalanches, volcanic eruptions, mud flows, highly susceptible natural resources, extreme topography, etc.) specify (Steep slopes: Low vegetation cover accelerates the runoff), poverty / wealth (Level of poverty in rural areas), education, access to knowledge and support services (High illiteracy rate in rural areas (27.9%))

Secondary causes of degradation: disturbance of water cycle (infiltration / runoff) (Low vegetation is not conducive to infiltration), land tenure

3.8 Prevention, reduction, or restoration of land degradation

Specify the goal of the Technology with regard to land degradation:

• restore/ rehabilitate severely degraded land

Comments:

Secondary goals: prevention of land degradation, mitigation / reduction of land degradation

4.1 Technical drawing of the Technology

4.2 Technical specifications/ explanations of technical drawing

Aloe Vera Living Barriers on slope of more than 60%. The soil accumulated behind the barrier can reach depths of 55 cm.

Date: 15.3.10

Technical knowledge required for field staff / advisors: moderate

Technical knowledge required for land users: moderate

Main technical functions: reduction of slope length, improvement of ground cover, improvement of topsoil structure (compaction), stabilisation of soil (eg by tree roots against land slides), increase of groundwater level / recharge of groundwater, sediment retention / trapping, sediment harvesting, increase of biomass (quantity)

Secondary technical functions: control of raindrop splash, reduction of slope angle, increase of surface roughness, increase in organic matter

Aligned: -contour
Vegetative material: O : other
Number of plants per (ha): 5000
Vertical interval between rows / strips / blocks (m): 2 (m)
Spacing between rows / strips / blocks (m): 5 (m)
Vertical interval within rows / strips / blocks (m): 0.4(m)

Grass species: Aloe vera plants

Slope (which determines the spacing indicated above): 60.00%

If the original slope has changed as a result of the Technology, the slope today is (see figure below): 50.00%

Gradient along the rows / strips: 0.00%

4.3 General information regarding the calculation of inputs and costs

Specify currency used for cost calculations:

• US Dollars

4.4 Establishment activities

	Activity	Type of measure	Timing
1.	Demarcation of contour lines, using water levels	Vegetative	Early June
2.	Collection of Aloe Vera plants (Aloe vera grows naturally on upper slopes and in depressions)	Vegetative	June
3.	Planting	Vegetative	End of June
4.	Dès la 2ème année, les espaces entre les plants d’Aloe vera se bouchent naturellement par leur propre croissance

4.5 Costs and inputs needed for establishment

	Specify input	Unit	Quantity	Costs per Unit	Total costs per input	% of costs borne by land users
Labour	Demarcation of contour lines,	persons/day/ha	15.0	3.3333	50.0
Labour	Planting	persons/day/ha	50.0	3.333333	166.67
Equipment	Tools	ha	1.0	13.0	13.0
Plant material	Plants	pieces	5000.0
Total costs for establishment of the Technology					229.67

Comments:

Duration of establishment phase: 1 month(s)

4.6 Maintenance/ recurrent activities

	Activity	Type of measure	Timing/ frequency
1.	Vegetative control: removal of Aloe vera plants that are invading cropland (maize, peas) between the life barriers	Vegetative	annually
2.	Replanting of Aloe vera to fill gaps in life barriers (very rare, survival rate is over 95%)	Vegetative

4.7 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	Vegetative control	persons/day/ha	10.0	3.3	33.0	100.0
Total costs for maintenance of the Technology					33.0

Comments:

Machinery/ tools: levels, hoes, shovels

Labour inputs for implementation are rewarded by project: individuals of poor communities receive a salary of 3.3 US$ per day. Plants are collected locally; their value on the market would be around 3-4 US$ per plant. Establishment costs do not include labour-intensive construction of stone risers (supportive measure). Maintenance costs are borne by land users.

4.8 Most important factors affecting the costs

Describe the most determinate factors affecting the costs:

The labour used in this technique consists of individuals from poor or very poor rural communities who come to work in search of an income with a payment of 250 Escudos per day.

5.1 Climate

5.2 Topography

Comments and further specifications on topography:

Slopes on average: The slope characteristic of most of the area is steep

Altitudinal zone: 500-1000 m a.s.l. occupies the largest area.

5.3 Soils

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 depth on average: The depth varies with altitude, being higher in low altitudes.

Soil fertility is medium

Soil drainage / infiltration is medium

Soil water storage capacity is low but high on barriers

5.4 Water availability and quality

Comments and further specifications on water quality and quantity:

Water quality (untreated): Much of the groundwater is saline due to over-exploitation of aquifers. But can also be good

5.5 Biodiversity

Comments and further specifications on biodiversity:

Most species are cultivated and others are introduced

5.6 Characteristics of land users applying the Technology

Indicate other relevant characteristics of the land users:

Land users applying the Technology are mainly Leaders / privileged

Population density: 100-200 persons/km2

Annual population growth: > 4%; 5%

1% of the land users are rich (0.5).
and own 3% of the land (1).
80% of the land users are poor (50).

Market orientation of production system: Subsistence mainly for rainfed crops.

5.7 Average area of land owned or leased by land users applying the Technology

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

Land ownership:

• individual, titled

• Diocese

Land use rights:

• leased
• individual

• hereditary

Water use rights:

• communal (organized)

• hereditary

5.9 Access to services and infrastructure

6.1 On-site impacts the Technology has shown

Socio-economic impacts

Production

Water availability and quality

Socio-cultural impacts

Ecological impacts

Water cycle/ runoff

Soil

Biodiversity: vegetation, animals

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	Type of climatic change/ extreme	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	well
local windstorm	well

Climatological disasters

	How does the Technology cope with it?
drought	not well

Hydrological disasters

	How does the Technology cope with it?
general (river) flood	well

Other climate-related consequences

Other climate-related consequences

	How does the Technology cope with it?
reduced growing period	well

Comments:

Aloe vera it is resistant to lack of water because of their physiognomy and anatomy, but can not resist a big drougth

6.4 Cost-benefit analysis

How do the benefits compare with the establishment costs (from land users’ perspective)?

How do the benefits compare with the maintenance/ recurrent costs (from land users' perspective)?

Comments:

The structure does not require costly maintenance, it is simply controlling the spacing of the barrier (vegetative control) and punctual replanting.

6.5 Adoption of the Technology

• 1-10%

If available, quantify (no. of households and/ or area covered):

400 households covering 10 percent of the stated area.

Of all those who have adopted the Technology, how many have did so spontaneously, i.e. without receiving any material incentives/ payments?

• 0-10%

Comments:

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

There is a little trend towards spontaneous adoption of the Technology

6.7 Strengths/ advantages/ opportunities of the Technology

Strengths/ advantages/ opportunities in the land user’s view
Improves the thickness of the soil leaving it stronger and more productive How can they be sustained / enhanced? The mineral and organic matter retained behind the lines of Aloe vera will promote an increase in the thickness of the soil, improving also the volume of water retained in the soil, resulting in better root development. Therefore, the process of soil formation is best done.

Strengths/ advantages/ opportunities in the compiler’s or other key resource person’s view
Recover the degraded land and increase the production How can they be sustained / enhanced? The vegetation of the area between the barriers will make the recovery and protection of the soil layer is stronger
Stabilizes the soil making it more resistant to the impact of the rain water How can they be sustained / enhanced? Sedimentation behind the barriers is favored along the time due to the continued growth of the plant Aloe vera

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?
Reduction of the production area, which is occupied by bands of Aloe vera	Annual vegetative control within cultivated area and by cutting Aloe vera plants growing outside the living barriers, using it more economically

7.3 Links to relevant information which is available online

Title/ description:

DESIRE-project. 2010.

URL:

http://www.desire-project.eu/