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)

Soil protection and rehabilitation for food security (ProSo(i)l)

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

Direction Générale de l’Amenagement et de Conservation des Terres Agricoles (DG/ACTA) - Tunisia

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

GIZ Tunisia (GIZ Tunisia) - Tunisia

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

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

1.5 Reference to Questionnaire(s) on SLM Approaches (documented using WOCAT)

2.1 Short description of the Technology

Definition of the Technology:

Mechanical bench terraces are a landscaping technique employed on sloping terrain. These are essentially mechanically constructed earthen levees or embankments established along contour lines.

2.2 Detailed description of the Technology

Description:

Mechanical bench terraces are anti-erosion structures that consist of embankment bunds accompanied by drainage channels. They are suitable for areas with high average annual rainfall and low rainfall intensity. The ideal conditions for their implementation include light to medium-textured soil rich in humus, a minimum top layer depth of 1.5 m, and a gentle slope ranging from 4 to 6%.
Designed as cascading structures that break the length of the slope, these terraces provide several advantages, including improvements in water quality and reduced downstream sedimentation. Properly constructed, this practice facilitates water infiltration into the soil, enhances soil fertility, and contributes to slowing erosion in small watersheds, while also aiding in surface water storage on farms. These embankments are designed to:
- prevent erosion on cereal-growing lands
- create a micro-climate favourable to arboriculture
- orient land cultivation along contour lines
- facilitate crop rotation
The technical specifications, including inter-embankment spacing, height, and width, vary based on site-specific conditions and conservation objectives. The installation and maintenance of mechanical total retention embankments requires several key activities and inputs, including:
- site analysis and planning to determine appropriate design and construction specifications
- heavy machinery and equipment for construction
- appropriate construction materials
- ongoing maintenance, including erosion and sedimentation monitoring, as well as periodic maintenance to repair or replace damaged terraces
Land users may hold differing opinions on total retention embankments, as they present both advantages and potential disadvantages. Some users appreciate the positive impacts on water quality and erosion reduction, while others are concerned about potential disruptions to land-use activities and the reduction in utilized agricultural area.

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

Comments (type of project, etc.):

The CES strategy planned for the 1990-2001 decade.

3.1 Main purpose(s) of the Technology

• improve production
• reduce, prevent, restore land degradation
• protect a watershed/ downstream areas – in combination with other Technologies
• create beneficial economic impact

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

Land use mixed within the same land unit:

No

3.3 Has land use changed due to the implementation of the Technology?

Has land use changed due to the implementation of the Technology?

• No (Continue with question 3.4)

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

• Intercropping

3.6 SLM measures comprising the Technology

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:

• reduce land degradation
• restore/ rehabilitate severely degraded land

4.1 Technical drawing of the Technology

4.2 General information regarding the calculation of inputs and costs

Specify how costs and inputs were calculated:

• per Technology area

other/ national currency (specify):

Tunisian dinars

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

3.1

4.3 Establishment activities

	Activity	Timing (season)
1.	Site selection: The first step is to select a suitable site for the mechanical embankments. The site must be located on a slope with sufficient rainfall for the embankment to be effective in terms of water conservation.
2.	Study and design: The next step is to study the site and design the mechanical embankments. The design of the embankment should consider the topography of the site, as well as factors such as soil type and the rainfall pattern in the area. These embankments should be engineered with the purpose of retaining all the water and soil that flows into them.
3.	Site preparation: Once the design has been completed, the site must be prepared for the construction of the mechanical benches. This may involve removing vegetation, levelling the site and preparing the foundations.
4.	Construction of the embankment: The mechanical embankment is built using a combination of earthmoving equipment and manual labor.
5.	Installation of water diversion structures: Water diversion structures are installed to ensure the retention of all water flowing over the embankment. These structures can include check dams, infiltration trenches and swales.
6.	Completion of the ridge of the embankment by means of a trax
7.	Subsoiling or ploughing

4.4 Costs and inputs needed for establishment

If you are unable to break down the costs in the table above, give an estimation of the total costs of establishing the Technology:

2500.0

If land user bore less than 100% of costs, indicate who covered the remaining costs:

Directorate-General for the Development and Conservation of Agricultural Lands

4.5 Maintenance/ recurrent activities

	Activity	Timing/ frequency
1.	Repair damage caused by erosion

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

If you are unable to break down the costs in the table above, give an estimation of the total costs of maintaining the Technology:

375.0

If land user bore less than 100% of costs, indicate who covered the remaining costs:

Directorate-General for the Development and Conservation of Agricultural Lands (DGACTA)

4.7 Most important factors affecting the costs

Describe the most determinate factors affecting the costs:

The cost of installing mechanical embankments is contingent on the site's condition. If the site is rocky or the soil is hard, construction may prove more challenging and time-consuming. Additionally, the size of a embankment bench influences the overall cost, as larger embankments require more materials, labor, and equipment.
Labour costs depend on the location and the availability of workers.

5.1 Climate

5.2 Topography

Indicate if the Technology is specifically applied in:

• not relevant

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.

Topsoil texture: medium fine
Reference soil depth (cm): 100
Organic carbon in topsoil (wt.%): 0.65
Topsoil pH (H2O): 6.9
Topsoil calcium carbonate (wt.%): 0.4
Topsoil gypsum (wt.%): 0.2
Topsoil sodicity (ESP) (%): 2
Topsoil salinity (ECe) (dS/m): 2.7
Subsoil texture: clayey silt (light) clayey silty clay (light)
Subsoil organic carbon (wt%): 0.27
Subsoil pH (H2O): 7.3
Subsoil calcium carbonate (weight %): 1.7
Subsoil gypsum (weight %): 0.5
Subsoil sodicity (ESP) (%): 2
Subsoil salinity (ECe) (dS/m): 1.7

5.4 Water availability and quality

Is water salinity a problem?

No

Is flooding of the area occurring?

Yes

Regularity:

episodically

5.5 Biodiversity

5.6 Characteristics of land users applying the Technology

5.7 Average area of land used by land users applying the Technology

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

Land ownership:

• individual, titled

Land use rights:

• individual

Water use rights:

• individual

Are land use rights based on a traditional legal system?

No

5.9 Access to services and infrastructure

6.1 On-site impacts the Technology has shown

Socio-economic impacts

Production

Income and costs

Socio-cultural impacts

Ecological impacts

Water cycle/ runoff

Soil

Biodiversity: vegetation, animals

Climate and disaster risk reduction

Specify assessment of on-site impacts (measurements):

On-site impact assessment is based on observations of land users and the results of research projects.

6.2 Off-site impacts the Technology has shown

Specify assessment of off-site impacts (measurements):

The assessment of external impacts is based on experts' estimates.

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?
seasonal rainfall	wet/ rainy season	decrease	very well

Climate-related extremes (disasters)

Meteorological disasters

	How does the Technology cope with it?
local rainstorm	very well

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

• > 50%

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

• 11-50%

6.6 Adaptation

Has the Technology been modified recently to adapt to changing conditions?

No

6.7 Strengths/ advantages/ opportunities of the Technology

Strengths/ advantages/ opportunities in the land user’s view
This technology ensures optimum soil moisture retention.
The embankments slow the flow of water, allowing it to infiltrate into the soil rather than causing runoff. This helps prevent soil erosion, preserves topsoil and promotes soil health and stability.
Embankments create microclimates suitable for vegetation growth.

Strengths/ advantages/ opportunities in the compiler’s or other key resource person’s view
Mechanical embankment technology adheres to the principles of sustainable land management, emphasizing the preservation of ecosystems, erosion mitigation, and responsible utilization of natural resources
Mechanical embankments help land users adapt to the challenges posed by climate change. Through the conservation of water, soil erosion control, and facilitation of vegetation growth, these embankments enable land users to mitigate the impacts of shifting climatic conditions, fostering the development of more resilient and sustainable landscapes.

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?
Reduced arable land	Diversify crops
Workload

Weaknesses/ disadvantages/ risks in the compiler’s or other key resource person’s view	How can they be overcome?
Technical complexity	Ongoing education
Maintenance and repairs	Biological consolidation of embankments with cactus, acacia, olive trees, etc.

7.1 Methods/ sources of information

7.2 References to available publications

Title, author, year, ISBN:

Guide de conservation des eaux et du Sol, Ministère de l’agriculture, Direction Générale de l'Aménagement et de la Conservations des Terres Agricoles, 1995: Ministère de l’agriculture, Direction Générale de l'Aménagement et de la Conservations des Terres Agricoles

Available from where? Costs?

Directorate-General for the Development and Conservation of Agricultural Lands, 1995: Ministry of Agriculture, Directorate-General for the Development and Conservation of Agricultural Lands.

Title, author, year, ISBN:

Carte agricole de la Tunisie, Ministère de l’agriculture, 2005

Available from where? Costs?

Ministry of Agriculture, Directorate-General for the Development and Conservation of Agricultural Lands

7.3 Links to relevant online information

Title/ description:

Influence du facteur lithologique sur l'échec des aménagements en banquettes de terre dans un petit bassin versant semi-aride tunisien, Noemen Baccari, 2021

URL:

https://www.researchgate.net/publication/349718199_Influence_du_facteur_lithologique_sur_l'echec_des_amenagements_en_banquettes_de_terre_dans_un_petit_bassin_versant_semi-aride_tunisien_Influence_of_lithological_factors_on_the_failure_of_ground_embank

Title/ description:

Evolution des techniques de conservation des eaux et des sols en Tunisie, Mohamed Boufaroua, 2004

URL:

https://beep.ird.fr/collect/bre/index/assoc/23-625-6.dir/23-625-635.pdf

Title/ description:

Les aménagements de conservation des eaux et des sols en banquettes : analyse, fonctionnement et essai de modélisation en milieu méditerranéen (El-Gouazine, Tunisie centrale), Youssef Al Ali, 2007

URL:

http://www.secheresse.info/spip.php?article24124

Title/ description:

Harmonized World Soil Database, FAO, 2009

URL:

https://www.fao.org/soils-portal/data-hub/soil-maps-and-databases/harmonized-world-soil-database-v12/en/