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)

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

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

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

Community tradition [South Africa]

Inherited, and still practiced, tradition of stone terracing - passed down from generation to generation.

• Compiler: William Critchley
• 01/15/2009 midnight

2.1 Short description of the Technology

Definition of the Technology:

Stone walls built on sloping fields to create terraces for cultivation and conservation: both ancient and contemporary.

2.2 Detailed description of the Technology

Description:

In this hilly, mixed farming area, stone terrace walls are a tradition. They are built across the slope when new land is cleared of loose stone and brought into crop cultivation. The dimensions of the terrace walls and the spacing between them depend on various factors, especially the slope and the amount of stone in the field. The walls may be up to 1.25 m high, from 1.0 to 1.5 m in base width, and between 20 and 50 m long. Spacing is from 3 to 10 m apart. Design of stone terrace walls varies. Some walls are very neatly built, others are merely piles of stone across the slope: this depends on the individual land user. The walls are built up each year with further stones: this may just be as more loose stone comes to the surface when ploughing, or also by digging out larger stones to deliberately build up the height of the walls as it silts up behind. Such terracing is generally confined to slopes between 20% and 50%. From 12% to 20% contour grass strips (thambaladza) are normally used, but below 12% land is rarely protected with structures or strips.

Purpose of the Technology: The purpose of terracing, apart from simultaneously clearing the land of stone, is to guard against loss of topsoil. Together with contour ploughing this helps to keep soil fertility in place on sloping cropland in a subhumid area. Rainfall is around 1,000 mm per annum and maize is the most common crop, but various other annuals (beans, pumpkins, sorghum etc) and perennials (peaches, avocadoes, oranges etc) are also grown.

Natural / human environment: This example of land conservation is probably unique in a former South African ‘homeland’. In such areas, where the black population were concentrated at high population densities under the former apartheid regime, land degradation rather than soil conservation was the rule. These terraces continue to be built to this day as new land is opened up, despite the high amounts of labour (300-500 person days per hectare) involved in establishment. A study of the conservation systems used in the area and local attitudes to them, showed that the benefits of conservation were well understood by local farmers (see reference). Those questioned identified retention of soil - and of soil fertility in particular - as being of paramount importance. No mention was made of terraces being built simply to remove surface stone. The only downside mentioned (by a few) was the loss of cultivable land area. The key to the persistence of the terraces in this area is, therefore, that the land users understand and appreciate the place of terraces in maintaining soil fertility, and their considerable contribution to crop production.

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:

South Africa

Region/ State/ Province:

Limpopo Province

Further specification of location:

Thononda Ward (Thohoyandou district)

Specify the spread of the Technology:

• evenly spread over an area

If the Technology is evenly spread over an area, specify area covered (in km2):

8.0

If precise area is not known, indicate approximate area covered:

• 1-10 km2

Comments:

Total area covered by the SLM Technology is 8 km2.

Within the Northern region of South Africa's Northern Province (formerly "Venda") a few areas are apparently covered with ancient stone terraces - but Thononda Ward of Thohoyandou district is the best example and the only one

Map

×

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.):

May have originated with the Shona of Zimbabwe and the tradition brought with them when some moved south to Venda

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

• Annual cropping
• Tree and shrub cropping

Annual cropping - Specify crops:

• cereals - maize

Tree and shrub cropping - Specify crops:

• avocado

Number of growing seasons per year:

• 1

Specify:

Longest growing period in days: 150; Longest growing period from month to month: Nov - May

Comments:

Major cash crop: Maize and avocado
Major food crop: Maize

Major land use problems (compiler’s opinion): Agreement with the land-user

Major land use problems (land users’ perception): Decline in fertility of soil, erosion on roads/from roads, yield burning leading to runoff.

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

• cross-slope measure

3.6 SLM measures comprising the Technology

agronomic measures

structural measures

• S1: Terraces

Comments:

Main measures: structural measures

Secondary measures: agronomic measures

3.7 Main types of land degradation addressed by the Technology

soil erosion by water

• Wt: loss of topsoil/ surface erosion

chemical soil deterioration

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

Comments:

Main causes of degradation: Heavy / extreme rainfall (intensity/amounts) (slope), other natural causes (avalanches, volcanic eruptions, mud flows, highly susceptible natural resources, extreme topography, etc.) specify (Slope/rainfall)

Secondary causes of degradation: other human induced causes (specify) (Burning of veld/grazing land upslope)

3.8 Prevention, reduction, or restoration of land degradation

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

• prevent land degradation

4.1 Technical drawing of the Technology

Technical specifications (related to technical drawing):

Layout of stone wall terraces: the walls are built up over time (right) as soil accumulates behind the barriers.

Date: Northern Province

Technical knowledge required for land users: moderate

Main technical functions: control of dispersed runoff: impede / retard

Secondary technical functions: reduction of slope angle, reduction of slope length

Structural measure: Bunds/banks: contour
Vertical interval between structures (m): varied
Spacing between structures (m): 3 -10
Height of bunds/banks/others (m): > 0.75
Width of bunds/banks/others (m): > 1.5
Length of bunds/banks/others (m): 20 -50

Construction material (stone): From within fields only

Slope (which determines the spacing indicated above): 30%

If the original slope has changed as a result of the Technology, the slope today is: 15%

Author:

Will Critchley, Amsterdam, The Netherlands

4.2 General information regarding the calculation of inputs and costs

Specify how costs and inputs were calculated:

• per Technology unit

Specify currency used for cost calculations:

• USD

4.3 Establishment activities

4.4 Costs and inputs needed for establishment

Comments:

Duration of establishment phase: 12 month(s)

4.5 Maintenance/ recurrent activities

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

Comments:

A 100 m x 100 m field with a slope of about 20 degrees (35%) with bund of 0,75 sqm cross section initially at 10 m horizontal intervals assuming 2 sqm moved per- person-day

4.7 Most important factors affecting the costs

Describe the most determinate factors affecting the costs:

Slope and amount of loose stones available (the more loose stones the more has to been moved to make cultivation possible)

5.1 Climate

5.2 Topography

Comments and further specifications on topography:

Altitudinal zone: 800 - 1200

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 texture: Mainly loans in cultivated areas

Soil fertility is medium

Soil drainage / infiltration is good

Soil water storage capacity is medium - high

5.6 Characteristics of land users applying the Technology

Indicate other relevant characteristics of the land users:

Level of mechanization: Also mechnanized.

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, not titled

Land use rights:

• open access (unorganized)
• 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

• single cases/ experimental

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

1 household

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

• 91-100%

Comments:

1% of land user families have adopted the Technology with external material support

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

Comments on acceptance with external material support: survey results

100% of land user families have adopted the Technology without any external material support

Comments on spontaneous adoption: estimates

There is a moderate trend towards spontaneous adoption of the Technology

Comments on adoption trend: As land becomes more limited for cultivation, people are forced to cultivate steeper and stonier land. This is a "living" tradition!

6.7 Strengths/ advantages/ opportunities of the Technology

6.8 Weaknesses/ disadvantages/ risks of the Technology and ways of overcoming them

7.1 Methods/ sources of information

7.2 References to available publications

Title, author, year, ISBN:

Case study of Vhavenda, perception of erosion.... June 97.

Available from where? Costs?

Paper submitted to "Development South Africa"