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)

Book project: where the land is greener - Case Studies and Analysis of Soil and Water Conservation Initiatives Worldwide (where the land is greener)

1.3 Conditions regarding the use of data documented through WOCAT

When were the data compiled (in the field)?

01/02/2004

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

Yes

1.4 Declaration on sustainability of the described Technology

Is the Technology described here problematic with regard to land degradation, so that it cannot be declared a sustainable land management technology?

No

2.1 Short description of the Technology

Definition of the Technology:

Gully rehabilitation by check dams made of stem cuttings from trees. These living barriers retard concentrated runoff and fill up the gullies gradually with sediment.

2.2 Detailed description of the Technology

Description:

Stem cuttings from specific tree species have the ability to strike roots and continue growing after being planted into the earth. In this case study local species have been used to create check dams in gullies: these include jinocuebo (Simaroubaceaes bombacaceaes, and also jobo, tiguilote, pochote from the same family). Other suitable species are jocote (Spondias purpurea) and madero negro (Gliricidia sepium). As an option the pinapple-like piñuela (Bromelia pinguin) can be planted in association with the stem cuttings to further reinforce the system. Tree stems are cut into pieces 5-15 cm thick and 1.5-2.5 m long, depending on the depth of the gully. The cuttings are planted to half of their length, and formed into semi-circular barriers (see diagram). The dams retard runoff and thus retain eroded sediment. Spacing between dams depends on the gradient of the gully bed. For example on a 15% slope it is recommended to build a dam every 4 meters (see spacing under establishment activities). Between dams, the gully gradually fills up with eroded soil, the speed of the runoff is further reduced and agricultural land that has been divided by the gully is reconnected. Large and deep gullies may change over time into a sequence of narrow fertile terraces where crops can be grown.

However, the check dams should be seen as part of an integrated catchment management and protection plan, and thus be supported by other SWC measures on the lateral slopes, such as retention ditches and/or live barriers laid out along the contour. Erosion and runoff control on the sides of each gully is an essential part of the rehabilitation process. These check dams of rooted poles are more robust and durable than stone dams in soils of sandy/ loamy texture. On moderate and steep slopes a combination of stem cutting and stone dams is recommended.

After two to three years the barriers should be pruned - yielding wood and fodder. Dead poles should be replaced and the dam widened if necessary.

In this case study the dams are constructed in a semi-arid region with erratic rainfall where gullies are common on agricultural land, be it cropland or grazing land. The land users are mainly peasant farmers, growing crops for subsistence on smallholdings, and living in very poor conditions. This system of gully rehabilitation is promoted by an NGO entitled ‘Asociación Tierra y Vida’ through farmerto-farmer (campesino a campesino) extension.

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:

• less than 10 years ago (recently)

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
• reduce risk of disasters

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

Comments:

Major land use problems (compiler’s opinion): There is a range of factors that limit agricultural production in the area: soil degradation, extensive gully formation on crop land, low soil fertility, lack of inputs for crop production, erratic precipitation. Also, lack of interest/knowledge and lack of resources hinder the implementation of SWC measures.

3.3 Further information about land use

Water supply for the land on which the Technology is applied:

• rainfed

Specify:

Longest growing period in days: 100, Longest growing period from month to month: May to August; Second longest growing period in days: 90, Second longest growing period from month to month: September to November

3.4 SLM group to which the Technology belongs

• cross-slope measure

3.5 Spread of the Technology

Comments:

Total area covered by the SLM Technology is 5 m2.

3.6 SLM measures comprising the Technology

Comments:

Specification of other vegetative measures: stem cuttings; live barriers along contour (supp.)
Specification of other structural measures: check dams; retention ditches

3.7 Main types of land degradation addressed by the Technology

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

4.1 Technical drawing of the Technology

4.2 Technical specifications/ explanations of technical drawing

Stem cuttings planted in gullies to form living check dams: recently planted (left) and cuttings that have begun to take root and sprout, resulting in the gully becoming filled with trapped sediment (right).

Technical knowledge required for field staff / advisors: low
Technical knowledge required for land users: moderate
Main technical functions: control of concentrated runoff: retain / trap, levelling of land
Secondary technical functions: reduction of slope angle, reduction of slope length

Construction material (wood): jinocuebo (Simaroubaceaes bombacaceaes, and also jobo, tiguilote, pochote from the same family), j
Slope (which determines the spacing indicated above): 15%

4.4 Establishment activities

	Activity	Type of measure	Timing
1.	Calculate and mark spacing between structures.	Structural	efore rainy season (April/May)
2.	Cut poles out of selected local trees (diameter: 5–15 cm,length: 1.5–2.5 m depending on gully depth).	Structural	before rainy season (April/May)
3.	Dig small semi-circular ditches at the gully bottom (the depth of theditch is half the length of the cuttings).	Structural	before rainy season (April/May)
4.	Plant the cuttings vertically into the ditch; put the thicker cuttingsin the middle of the gully where runoff velocity is higher.	Structural	efore rainy season (April/May)
5.	Fill ditch with excavated earth to fix the cuttings.	Structural	before rainy season (April/May)
6.	Water to encourage rooting.	Structural	before rainy season (April/May)

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	labour	ha	1.0	100.0	100.0	100.0
Equipment	tools	ha	1.0	20.0	20.0
Equipment	wheelbarrow	ha	1.0	10.0	10.0	100.0
Construction material	wood	ha	1.0	60.0	60.0	100.0
Total costs for establishment of the Technology					190.0

Comments:

Duration of establishment phase: 2 month(s)

4.6 Maintenance/ recurrent activities

	Activity	Type of measure	Timing/ frequency
1.	Biotrampas: pruning the trees	Structural	every three years.
2.	Cut-off drains: clearing of sediment, cutting bushes and grasses.	Structural
3.	Stone check dams: pruning trees and bushes every three years. After fullsedimentation, the dam may be increased in height.	Structural
4.	Wooden check dams: pruning trees and bushes	Structural	every three years.

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	labour	ha	1.0	30.0	30.0	100.0
Construction material	wood	ha	1.0	5.0	5.0	100.0
Total costs for maintenance of the Technology					35.0

Comments:

Costs are calculated for a 100 m long, 2 m wide and 1 m deep gully with check dams every 4 m, on the basis of one gully per hectare.

4.8 Most important factors affecting the costs

Describe the most determinate factors affecting the costs:

The wood (for poles) belongs to the land users themselves, thus the ‘cost’ does not involve purchase.

5.1 Climate

5.2 Topography

5.3 Soils

5.6 Characteristics of land users applying the Technology

Indicate other relevant characteristics of the land users:

Off-farm income specification: temporary or permanent migration, particularly young people

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, not titled
• individual, titled

Land use rights:

• leased
• individual

6.1 On-site impacts the Technology has shown

Socio-economic impacts

Production

Income and costs

Socio-cultural impacts

Ecological impacts

Soil

6.2 Off-site impacts the Technology has shown

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)?

6.5 Adoption of the Technology

• more than 50%

Comments:

66% of land user families have adopted the Technology with external material support
30% of all farmers approached by the project (about 400 out of 1,200 land users) have built these check dams. Seeds, tools and credits were provided as incentives; the reasons for implementation included both the attraction of the incentives and perceived ecological benefits in terms of rehabilitation of degraded areas.

34% of land user families have adopted the Technology without any external material support

There is a strong trend towards spontaneous adoption of the Technology

6.7 Strengths/ advantages/ opportunities of the Technology

Strengths/ advantages/ opportunities in the compiler’s or other key resource person’s view
Facilitated land management: area is no longer divided by gullies
Retards runoff speed: decreases erosion
Accumulation of fertile earth above the check dams, possibility of growing crops on ‘terraces’ between the structures
Increased soil moisture

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?
The check dams used alone as SWC measure may not be adequate to withstand concentrated runoff	It is important to combine this technology with other SWC practices (e.g. retention ditches on slopes at both sides of gully, live fences, etc).
Only likely to be applied where land use rights are guaranteed.
Labour intensive.

7.1 Methods/ sources of information

7.2 References to available publications

Title, author, year, ISBN:

Gurdiel G . La construcción de diques. Tierra Fresca, Simas-Enlace, Managua. 1993.

Title, author, year, ISBN:

Guía Técnica de Conservación de Suelos y Agua. PASOLAC, Managua. 2000.

Title, author, year, ISBN:

LUPE . Manual Práctico de Manejo de Suelos en Laderas. Secretaría de Recursos Naturales, Tegucigalpa, Honduras. 1994.