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Technologies
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Barrières végétales d’Aloe vera [Cape Verde]

Live barriers with Aloe vera (Cape Verde)

technologies_1334 - Cape Verde

Completeness: 78%

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:

Cape Verde

SLM specialist:

Cape Verde

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:

Ja

2. Description of the SLM Technology

2.1 Short description of the Technology

Definition of the Technology:

Cette technologie consiste à planter des barrières végétales le long des courbes de niveau afin de réhabiliter et stabiliser les pentes dégradées.

2.2 Detailed description of the Technology

Description:

L’Aloe vera est une plante charnue et résistante à la sécheresse plantée sous forme de barrières végétales afin de régénérer les pentes dégradées des Îles du Cap Vert. Les plantes sont plantées de façon serrée le long des courbes de niveau pour former des barrières efficaces, afin de retenir les sédiments érodés et le ruissellement. Ces haies stabilisent le sol et augmentent le taux d’humidité du sol en améliorant l’infiltration et la structure du sol. La terre s’accumule derrière les bandes d’Aloe et la pente s’atténue considérablement au fil du temps. La nappe phréatique est indirectement rechargée. La couverture du sol augmente et l’évaporation diminue.
La mise en œuvre est relativement simple. Les courbes de niveau sont tracées grâce à un niveau à corde ou à eau, puis des plants sont plantés tous les 30-50 cm, en espaçant les lignes de 6-10 m, en fonction de la pente. La technologie est utilisée dans les zones subhumides et semi-arides, sur des pentes raides à sols peu profonds, à végétation éparse et à forte érosion. Ces zones sont généralement exploitées par des paysans pauvres pratiquant l’agriculture pluviale de subsistance avec du maïs et des haricots, qui ne sont pas habituellement plantés sur de telles pentes. Sur les pentes supérieures à 30%, les barrières végétales sont souvent associées à des murs en pierres (largeur 40-50 cm, hauteur 80-90 cm). Comme les plantes stabilisent les murs, cette mesure combinée est l’une des plus efficaces pour contrôler l’érosion sur le Cap.
L’Aloe vera est bien adaptée aux conditions biophysiques locales et au mode d’exploitation habituel des terres : elle peut être associée à toutes les cultures et elle est accessible aux fermiers. La plantation et le transport sont faciles, les feuilles ne sont pas consommées par le bétail, elle est extrêmement résistante au stress hydrique et pousse dans toutes les zones bioclimatiques de l’île. De plus, l’Aloe vera est réputée pour ses nombreux usages médicaux traditionnels.

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:

Cape Verde

Region/ State/ Province:

Santiago

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. 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

Cropland

Cropland

  • Annual cropping
Grazing land

Grazing land

Extensive grazing land:
  • Semi-nomadism/ pastoralism
  • Ranching
Intensive grazing/ fodder production:
  • Cut-and-carry/ zero grazing
Comments:

Major land use problems (compiler’s opinion): Erosion hydrique, perte de la couche arable du sol

Semi-nomadism / pastoralism: surtout pour les caprins

Ranching: Yes

Cut-and-carry/ zero grazing: pour les bovins

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: Aug-Oct

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 m2.

3.6 SLM measures comprising the Technology

vegetative measures

vegetative measures

  • V2: Grasses and perennial herbaceous plants
Comments:

Main measures: vegetative measures

Type of vegetative measures: alignées: - isohypse

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
  • Wg: gully erosion/ gullying
biological degradation

biological degradation

  • Bc: reduction of vegetation cover
water degradation

water degradation

  • Ha: aridification
  • Hs: change in quantity of surface water
Comments:

Main type of degradation addressed: Wt: perte du sol de surface par l’eau, Wg: ravinement / érosion par ravinement, Bc: réduction de la couverture végétale, Ha: aridification, Hs: variation dans la quantité d’eau de surface

Main causes of degradation: gestion des sols, surpâturage, perturbation du cycle de l’eau (infiltration/ruissellement), sécheresses, autres causes naturelles (avalanches, éruptions volcaniques, topographie extrême, coulée de boue, etc.) Spécifier. (pentes raides), éducation, accès à la connaissance et aux conseils

Secondary causes of degradation: régime foncier, pauvreté / santé

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:

Main goals: rehabilitation / reclamation of denuded land

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

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

4.2 Technical specifications/ explanations of technical drawing

Technical knowledge required for field staff / advisors: faible

Technical knowledge required for land users: faible

Main technical functions: réduction de la longueur de la pente, amélioration de la couverture du sol, amélioration de la structure de la couche arable du sol (tassement, compaction), stabilisation du sol (par ex. par des racines d’arbres contre les glissements de terrain), augmentation du niveau / recharge de la nappe phréatique, rétention / capture des sédiments, recueil des sédiments, augmentation de la biomasse (quantité)

Secondary technical functions: contrôle de la battance (‘splash’), réduction de la pente (angle de la pente), augmentation de la rugosité de surface, augmentation de la matière organique

Aligned: -contour
Vegetative material: C: cultures pérennes
Number of plants per (ha): 5000
Vertical interval between rows / strips / blocks (m): 2.00
Spacing between rows / strips / blocks (m): 5.00
Vertical interval within rows / strips / blocks (m): 0.40

Perennial crops species: Aloe vera

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. Marquage des courbes de niveau avec un niveau à corde ou à eau; distance entre les lignes : 6 m minimum Vegetative Début juin
2. Récolte de plants d’Aloe vera, qui pousse abondamment sur les pentes élevées, dans des vallons / creux, aussi bien dans des zones arides que plus humides Vegetative None
3. Mise en terre des plants d’Aloe, les uns à côté des autres ou à 30-50 cm; à la houe ou à la pioche Vegetative fin juin
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 None None 15.0 3.3333 50.0
Labour None None 50.0 3.333333 166.67
Equipment None None 1.0 13.0 13.0
Plant material None None 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. Contrôle de la végétation : arracher les plants d’Aloe vera qui envahissent les cultures (maïs, pois) entre les barrières végétales Vegetative None
2. Replanter des plants d’Aloe vera dans les trous des barrières végétales (très rare, le taux de reprise est de 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 None None 10.0 3.3 33.0 100.0
Total costs for maintenance of the Technology 33.0
Comments:

Machinery/ tools: niveaux, houes, pelles

4.8 Most important factors affecting the costs

Describe the most determinate factors affecting the costs:

Les apports en main-d’œuvre pour la mise en œuvre sont rémunérés par le projet : les participants des communautés pauvres reçoivent 3 US$/jour. Les plants sont récoltés localement. Les coûts de mise en place n’incluent pas la construction très laborieuse des murets en pierre. Les coûts d’entretien sont assumés par les exploitants agricoles

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
  • humid
  • sub-humid
  • semi-arid
  • 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)
  • medium (loamy, silty)
Topsoil organic matter:
  • medium (1-3%)
  • low (<1%)

5.4 Water availability and quality

Ground water table:

5-50 m

Availability of surface water:

poor/ none

Water quality (untreated):

poor drinking water (treatment required)

5.5 Biodiversity

Species diversity:
  • low

5.6 Characteristics of land users applying the Technology

Market orientation of production system:
  • subsistence (self-supply)
  • mixed (subsistence/ commercial
Relative level of wealth:
  • average
  • rich
Individuals or groups:
  • individual/ household
Level of mechanization:
  • manual work
  • mechanized/ motorized
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.
19% of the land users are average wealthy.
80% of the land users are poor.

Market orientation of production system: subsistence (self-supply), subsistence (self-supply), mixed (subsistence/ commercial

5.7 Average area of land owned or leased 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)?
  • medium-scale
Comments:

Average area of land owned or leased by land users applying the Technology: < 0.5 ha, 0.5-1 ha, 1-2 ha, 2-5 ha

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

Land ownership:
  • individual, titled
  • Diocese
Land use rights:
  • leased
  • individual
  • herité
Water use rights:
  • communal (organized)
  • herité

5.9 Access to services and infrastructure

health:
  • poor
  • moderate
  • good
education:
  • poor
  • moderate
  • good
technical assistance:
  • poor
  • moderate
  • good
employment (e.g. off-farm):
  • poor
  • moderate
  • good
markets:
  • poor
  • moderate
  • good
energy:
  • poor
  • moderate
  • good
roads and transport:
  • 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

Production

crop production

decreased
increased

fodder production

decreased
increased

fodder quality

decreased
increased

animal production

decreased
increased

wood production

decreased
increased

risk of production failure

increased
decreased

production area

decreased
increased
Water availability and quality

drinking water availability

decreased
increased

demand for irrigation water

increased
decreased

Socio-cultural impacts

food security/ self-sufficiency

reduced
improved

cultural opportunities

reduced
improved

SLM/ land degradation knowledge

reduced
improved

conflict mitigation

worsened
improved

Ecological impacts

Water cycle/ runoff

water quantity

decreased
increased

water quality

decreased
increased

harvesting/ collection of water

reduced
improved

surface runoff

increased
decreased

excess water drainage

reduced
improved

evaporation

increased
decreased
Soil

soil moisture

decreased
increased

soil cover

reduced
improved

soil organic matter/ below ground C

decreased
increased
Biodiversity: vegetation, animals

biomass/ above ground C

decreased
increased

plant diversity

decreased
increased

animal diversity

decreased
increased

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 résiste au stress hydrique et s’établit bien dans les différentes zones climatiques

6.4 Cost-benefit analysis

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

slightly negative

Long-term returns:

very positive

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

neutral/ balanced

Long-term returns:

very positive

Comments:

L’entretien n’est pas très coûteux : il consiste simplement contrôler la végétation et à replanter ponctuellement

6.5 Adoption of the Technology

  • 1-10%
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:

95% of land user families have adopted the Technology with external material support

380 land user families have adopted the Technology with external material support

5% of land user families have adopted the Technology without any external material support

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

There is a little trend towards spontaneous adoption of the Technology

Comments on adoption trend: La plupart des exploitants agricoles ont mis la technologie en œuvre grâce à des subventions (paiements). 380 exploitants ont adopté la technologie ; la surface plantée avec des barrières végétales d’Aloe vera est de 71,5 km². Il y a une légère tendance à

6.7 Strengths/ advantages/ opportunities of the Technology

Strengths/ advantages/ opportunities in the land user’s view
Amélioration de la couche arable du sol

How can they be sustained / enhanced? Maintien annuel: arracher les plantes en dehors des barrières végétales
Strengths/ advantages/ opportunities in the compiler’s or other key resource person’s view
Rehabilitation des terres dégradés et augmentation de la terre cultivable
Stabilisation du sol

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 de la surface cultivable à cause des bandes de Aloea Maintien annuel: arracher les plantes en dehors des barrières végétales

7. References and links

7.2 References to available publications

Title, author, year, ISBN:

DESIRE-project. 2010.

Available from where? Costs?

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

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