Technologies

Restoration of degraded rangeland [South Africa]

Rehabilitation/restoration of an area, after control of alien invasive species.

technologies_1416 - South Africa

Completeness: 76%

1. Informação geral

1.2 Detalhes do contato das pessoas capacitadas e instituições envolvidas na avaliação e documentação da tecnologia.

Pessoa(s)-chave

SLM specialist:
SLM specialist:

Van Rensburg Leon

South Africa

SLM specialist:

Fulls Erich

South Africa

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)
Name of project which facilitated the documentation/ evaluation of the Technology (if relevant)
Sustainable Land Management Practices of South Africa (SLM South Africa)

1.3 Condições em relação ao uso da informação documentada através de WOCAT

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

Sim

1.4 Declaração de sustentabilidade da tecnologia descrita

A tecnologia descrita aqui é problemática em relação a degradação da terra de forma que não pode ser declarada uma tecnologia sustentável de gestão de terra?

Não

2. Descrição da tecnologia de gestão sustentável da terra

2.1 Descrição curta da tecnologia

Definição da tecnologia:

Eradication of invasive species and revegetation of degraded rangelands by different treatments, including oversowing with grass seed mixture, supplementing with lime, cattle dung, and "brush packing" (laid out branches).

2.2 Descrição detalhada da tecnologia

Descrição:

A research investigation was undertaken in an area of degraded communal rangeland, which had been invaded by an alien tree species (Acacia mearnsii – black wattle). Competition from the water-demanding A. mearnsii, combined with overgrazing, had resulted in an almost total absence of palatable grasses. All that was left were a few patches of star grass (or ‘bermuda grass’: Cynodon dactylon). Prior to the research, discussions were held between personnel of the ‘Working for Water’ programme of the South African government and community members.
The purpose of the trials was to determine how best to eradicate the invasive trees and revegetate the rangeland. The restoration area was not fenced off and was thus open to grazing. The trials comprised five treatments, with three replicates each, on plots of 10 m by 20 m. In all treatments the A. mearnsii was eradicated manually, and chemical biocide applied to the stumps to prevent regrowth. Lime and grass seed (of palatable species) were applied to the loosened surface and covered with soil. The five treatments were:
(A) oversowing with grass seed mixture, supplementing of dolomitic lime, cattle dung, and ‘brush packing’ (see below for explanation of term);
(B) oversowing with grass seed mixture and supplementing with cattle dung;
(C) oversowing with grass seed mixture and supplementing with dolomitic lime;
(D) oversowing with grass seed mixture and brush packing;
(E) oversowing with grass seed mixture only.
In addition stone lines were laid out along the contour, between plots. The ‘brush packing’, referred to in treatments A and D comprised branches laid out in strips across the slope to retard runoff, trap soil, improve the micro-climate for establishing grass seedlings and protect the young plants from browsing by animals. The results showed treatment A to be the most effective in restoring the productive and protective function of the rangeland. From the trials, the estimated costs of applying the best technology would be US$ 230 per hectare. The key constraints for successful adoption however are not just technical, but include: (1) the need to protect the area from grazing and trampling by animals during the establishment period; (2) stopping removal of brushwood for firewood; and (3) the need for community agreement on initial protection and subsequent sustainable utilisation of the restored range.

Establishment activities:
1.Manual eradication of trees with chain saw and axe
2.Application of chemical biocide to the stumps to prevent any regrowth
3.Ripping of soil surface to a depth of 5 cm using a three tined hand implement
4.Application of dolomitic lime and raking it into soil after ripping of the soil
5.Application of organic material (cattle dung) after ripping and lime application
6.Oversowing with grass seed mixture after ripping of the soil and application of lime and organic material
7.Brush packing against contour and packing of rock contours against the slope All the branches and stones were collected from the restoration area. Rock contours were packed against (perpendicular) to the slope in the study area at varying intervals (approximately 10-15 m apart) in order to retard runoff water, trap soil, and improve conditions for seed germination (see inserted drawing below and attachment). Branches were packed (brush packing) along the slope in certain treatments within the study site in order to trap soil, retard runoff water en serve as a micro-climate for germinating and establishing grass seedlings
Total duration of restoration took 3 years, from removal of trees till revegetation trials were laid out and technology was established.

Maintenance / recurrent activities per year:
Following initial establishment maintenance was limited to 2 follow up applications of herbicide (after 3 and 5 months). Maintenance of contours was not done after restoration.

2.3 Fotos da tecnologia

2.5 País/região/locais onde a tecnologia foi aplicada e que estão cobertos nesta avaliação

Country:

South Africa

Region/ State/ Province:

Gauteng

Further specification of location:

Johannesburg

Especifique a difusão da tecnologia :
  • Uniformemente difundida numa área
If the Technology is evenly spread over an area, specify area covered (in km2):

9,0

If precise area is not known, indicate approximate area covered:
  • 1-10 km2
Comentários:

Total area covered by the SLM Technology is 9 km2.
Big area near settlement, was previously invaded by alien invasive species (such as A. mearnsii). Aim was to eradicate this species by using chemical/manual methods and to revegetate area with grass species occurring naturally.

2.6 Data da implementação

Caso o ano exato seja desconhecido, indique a data aproximada:
  • less than 10 years ago (recently)

2.7 Introdução da tecnologia

Especifique como a tecnologia foi introduzida:
  • durante experiências/pesquisa
Comentários (tipos de projeto, etc.):

It originated from the overall need to restore degraded rangelands.

3. Classificação da tecnologia de gestão sustentável da terra

3.1 Principal/principais finalidade(s) da tecnologia

  • Reduz, previne, recupera a degradação do solo

3.2 Tipo(s) atualizado(s) de uso da terra onde a tecnologia foi aplicada

Pastagem

Pastagem

Extensive grazing:
  • Semi-nomadic pastoralism
  • cattle
Comentários:

Major land use problems (compiler’s opinion): Occurrence of bare areas after control of alien invasive.
Major land use problems (land users’ perception): Minimal grazing for cattle, due to the occurrence of bare areas.
Grazingland comments: No area closure, thus livestock graze freely on statelands and thus causes overgrazing over a large area.
This is a constraint to management in grazing lands. No rotational grazing. No area closure, thus livestock graze freely on statelands and thus causes overgrazing over a large area.

Number of growing seasons per year: 1
Longest growing period in days: 210, Longest growing period from month to month: Oct - April

3.4 Water supply

Abastecimento de água para a terra na qual a tecnologia é aplicada:
  • Precipitação natural

3.5 Grupo de gestão sustentável da terra ao qual pertence a tecnologia

  • Gestão de pastoralismo e pastagem

3.6 Medidas de gestão sustentável da terra contendo a tecnologia

Medidas agronômicas

Medidas agronômicas

  • A7: Others
Medidas vegetativas

Medidas vegetativas

  • V5: Outros
Medidas estruturais

Medidas estruturais

  • S11: Outros
Comentários:

Specification of other agronomic measures: manuring, lime, 'brush packing' (trash lines)
Specification of other vegetative measures: oversowing grass seed mixture
Specification of other structural measures: stone lines
Type of vegetative measures: in blocks

3.7 Principais tipos de degradação da terra abordados pela tecnologia

Erosão do solo pela água

Erosão do solo pela água

  • Wt: Perda do solo superficial/erosão de superfície
Deteriorização química do solo

Deteriorização química do solo

  • Cn: declínio de fertilidade e teor reduzido de matéria orgânica (não causado pela erosão)
Deteriorização física do solo

Deteriorização física do solo

  • Pc: Compactação
Degradação biológica

Degradação biológica

  • Bc: redução da cobertura vegetal
Comentários:

Main causes of degradation: deforestation / removal of natural vegetation (incl. forest fires) (Alien invasives.), over-exploitation of vegetation for domestic use (Trampling.), overgrazing (Cattle and goat.)
Secondary causes of degradation: poverty / wealth (Lack of captial - To pay labours to apply technologies.), labour availability (Lack of labour - To remove alien species.)

3.8 Redução, prevenção ou recuperação da degradação do solo

Especifique o objetivo da tecnologia em relação a degradação da terra:
  • Reduzir a degradação do solo
  • Recuperar/reabilitar solo severamente degradado

4. Especificações técnicas, implementação de atividades, entradas e custos

4.1 Desenho técnico da tecnologia

Especificações técnicas (relacionada ao desenho técnico):

Specifications
Location: Elandsfontein. Gauteng
Technical knowledge required for field staff / advisors: high
Technical knowledge required for land users: moderate

Main technical functions: control of raindrop splash, control of dispersed runoff: retain / trap, increase in organic matter, sediment retention / trapping, sediment harvesting, increase in soil fertility, improvement of ground cover
Secondary technical functions: control of dispersed runoff: impede / retard, reduction of slope angle, increase of surface roughness, increase of infiltration, water harvesting / increase water supply, water spreading, reduction in wind speed, improvement of soil structure

Vegetative measure: contour
Vegetative material: O : other
Number of plants per (ha): 0
Vertical interval between rows / strips / blocks (m): 0.3
Spacing between rows / strips / blocks (m): 3
Vertical interval within rows / strips / blocks (m): 0
Width within rows / strips / blocks (m): 0.3
Vegetative measure: Vegetative material: O : other
Grass species: Mixture of perennial and annual grasses
Other species: rocks
Slope (which determines the spacing indicated above): 5.00%

Autor:

Anuschka Barac

4.2 Informação geral em relação ao cálculo de entradas e custos

Outro/moeda nacional (especifique):

Rand

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

8,2

Indique a média salarial da mão-de-obra contratada por dia:

4.30

4.3 Atividades de implantação

Atividade Timing (season)
1. Eradication of trees, Follow-up with herbicide beginning of project
2. Loosening of soil, Lime application 6 months
3. Application of organic material 6 months
4. Oversowing with grass seed mixture 6 months
5. Brush packing 6 months

4.4 Custos e entradas necessárias para a implantação

Especifique a entrada Unidade Quantidade Custos por unidade Custos totais por entrada % dos custos arcados pelos usuários da terra
Mão-de-obra labour ha 1,0 35,0 35,0
Equipamento machine use ha 1,0 65,0 65,0
Equipamento tools ha 1,0 5,0 5,0
Material vegetal seeds ha 1,0 70,0 70,0
Fertilizantes e biocidas fertilizer ha 1,0 25,0 25,0
Fertilizantes e biocidas biocides ha 1,0 30,0 30,0
Custos totais para a implantação da tecnologia 230,0
Total costs for establishment of the Technology in USD 28,05
Comentários:

Duration of establishment phase: 35 month(s)

4.5 Atividades recorrentes/manutenção

Atividade Calendarização/frequência
1. 2 Follow-ups with herbicide after 3 & 5 months after application of technology /twice (at 3 and 5 months )

4.6 Custos e entradas necessárias pata a manutenção/atividades recorrentes (por ano)

Especifique a entrada Unidade Quantidade Custos por unidade Custos totais por entrada % dos custos arcados pelos usuários da terra
Mão-de-obra labour ha 1,0 7,0 7,0
Equipamento tools ha 1,0 5,0 5,0
Fertilizantes e biocidas biocides ha 1,0 20,0 20,0
Custos totais para a manutenção da tecnologia 32,0
Total costs for maintenance of the Technology in USD 3,9
Comentários:

Eradication, seed purchasing, materials.

4.7 Fatores mais importantes que afetam os custos

Descreva os fatores mais determinantes que afetam os custos:

Biocides, fertilisers (lime), seeds and labour have a great effect on costs.

5. Ambiente naturale e humano

5.1 Clima

Precipitação pluviométrica anual
  • <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
Especificações/comentários sobre a pluviosidade:

600 - 800 mm/annum

Zona agroclimática
  • Subúmido

5.2 Topografia

Encostas em média:
  • Plano (0-2%)
  • Suave ondulado (3-5%)
  • Ondulado (6-10%)
  • Moderadamente ondulado (11-15%)
  • Forte ondulado (16-30%)
  • Montanhoso (31-60%)
  • Escarpado (>60%)
Formas de relevo:
  • Planalto/planície
  • Cumes
  • Encosta de serra
  • Encosta de morro
  • Sopés
  • Fundos de vale
Zona de altitude:
  • 0-100 m acima do nível do mar
  • 101-500 m acima do nível do mar
  • 501-1.000 m acima do nível do mar
  • 1.001-1.500 m acima do nível do mar
  • 1.501-2.000 m acima do nível do mar
  • 2.001-2.500 m acima do nível do mar
  • 2.501-3.000 m acima do nível do mar
  • 3.001-4.000 m acima do nível do mar
  • > 4.000 m acima do nível do mar

5.3 Solos

Profundidade do solo em média:
  • Muito raso (0-20 cm)
  • Raso (21-50 cm)
  • Moderadamente profundo (51-80 cm)
  • Profundo (81-120 cm)
  • Muito profundo (>120 cm)
Textura do solo (solo superficial):
  • Médio (limoso, siltoso)
Matéria orgânica do solo superficial:
  • Baixo (<1%)

5.6 Características dos usuários da terra que utilizam a tecnologia

Orientação de mercado do sistema de produção:
  • Subsistência (autoabastecimento)
  • Comercial/mercado
Rendimento não agrícola:
  • >50% de toda renda
Nível relativo de riqueza:
  • Média
  • Muito rico
Indique outras características relevantes dos usuários da terra:

Population density: 10-50 persons/km2
Annual population growth: 3% - 4%
80% of the land users are very rich (informal settlers and own 60% of the land (government).
20% of the land users are average wealthy and own 40% of the land (farmers).
Off-farm income specification: Informal settlers work in the city/mine, also mostly live of old age pension funds. Farmers (low percentage) have an income on-farm by means of selling cattle, crops and dairy products.

5.7 Average area of land used 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

5.8 Propriedade de terra, direitos de uso da terra e de uso da água

Propriedade da terra:
  • Estado
  • provincial government
  • provincial government

6. Impactos e declarações finais

6.1 Impactos no local mostrados pela tecnologia

Impactos socioeconômicos

Produção

Gestão de terra

Impedido
Simplificado
Comentários/especificar:

Brush packing was removed by community members for firewood.

Renda e custos

Rendimento agrícola

Diminuído
Elevado

Carga de trabalho

Elevado
Diminuído
Comentários/especificar:

Not all labourers could be employed, more would have like to have the job (money).

Impactos socioculturais

Instituições comunitárias

Enfraquecido
Fortalecido

Conhecimento de gestão sustentável da terra/degradação da terra

Reduzido
Melhorado
Comentários/especificar:

Capacity building awareness

Atenuação de conflitos

Agravado
Melhorado
Comentários/especificar:

Farmers not positive about SWC project and effect.

Impactos ecológicos

Ciclo hídrico/escoamento

Drenagem de excesso de água

Reduzido
Melhorado
Solo

Umidade do solo

Diminuído
Elevado

Cobertura do solo

Reduzido
Melhorado

Perda de solo

Elevado
Diminuído
Quantidade anterior à gestão sustentável da terra:

2

Quantidade posterior à gestão sustentável da terra:

1

Clima e redução de riscos de desastre

Velocidade do vento

Elevado
Diminuído

6.2 Impactos externos mostrados pela tecnologia

Cheias de jusante

Elevado
Reduzido

Sedimentação a jusante

Elevado
Diminuído

Sedimentos transportados pelo vento

Elevado
Reduzido

6.4 Análise do custo-benefício

Como os benefícios se comparam aos custos de implantação (do ponto de vista dos usuários da terra)?
Retornos a curto prazo:

ligeiramente negativo

Retornos a longo prazo:

positivo

Como os benefícios se comparam aos custos recorrentes/de manutenção(do ponto de vista dos usuários da terra)?
Retornos a curto prazo:

positivo

Retornos a longo prazo:

ligeiramente negativo

6.5 Adoção da tecnologia

Comentários:

10 land user families have adopted the Technology with external material support
1 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 Pontos fortes/vantagens/oportunidades da tecnologia

Strengths/ advantages/ opportunities in the land user’s view
Gazing improvement.
Strengths/ advantages/ opportunities in the compiler’s or other key resource person’s view
Improvement of grazing resources.
Improved soil moisture availability by removing an alien species with a high water demand.
Reduced erosion by controlling runoff.

6.8 Pontos fracos, desvantagens/riscos da tecnologia e formas de superá-los

Weaknesses/ disadvantages/ risks in the compiler’s or other key resource person’s view How can they be overcome?
The question of controlling ‘open access’ grazing by the community is the key to long-term success of rehabilitation It is incumbent on the local municipal council to negotiate with communities regarding grazing control and community-based natural resource management more generally.
Removal of brushwood for firewood by community members and other aspects of long-term maintenance See above: perhaps also seeking funds to pay labourers and buy biocides
Too many cattle and goats. Reduce numbers to match grazing resources available
Insufficient aftercare. Secure additional funds to pay labourers and buy biocides.

7. Referências e links

7.1 Métodos/fontes de informação

  • field visits, field surveys
  • interviews with land users
When were the data compiled (in the field)?

28/09/2001

7.2 Referências às publicações disponíveis

Title, author, year, ISBN:

Soil classification: A taxonomic system for South Africa.. 1991.

Available from where? Costs?

ARC -Institute for Soil, Climate and Water, Pretoria. 012 - 3102500.

Title, author, year, ISBN:

Harris J.A., Birch P., Palmer J.P. Land restoration and reclamation.. 1996.

Title, author, year, ISBN:

Kent M, Coker P. Vegetation description and analysis.. 1997.

Title, author, year, ISBN:

Tainton N. Veld management in South Africa.. 1999.

Title, author, year, ISBN:

Acocks. Veld types of South Africa.. 1988.

Title, author, year, ISBN:

HARRIS, J. A., BIRCH, P. AND PALMER, J. P. Land restoration and reclamation – Principles and Practices. Addison Wesley Longman, England. 230 p.. 1996.

Links and modules

Expand all Collapse all

Modules