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

Nome da(s) instituição(ões) que facilitou(ram) a documentação/ avaliação da Tecnologia (se relevante)

Université catholique de Louvain (Université catholique de Louvain) - Bélgica

Nome da(s) instituição(ões) que facilitou(ram) a documentação/ avaliação da Tecnologia (se relevante)

Centre for Agriculture in the Tropics and Subtropics (Centre for Agriculture in the Tropics and Subtropics) - Alemanha

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

Quando os dados foram compilados (no campo)?

01/08/1999

O/a compilador/a e a(s) pessoa(s) capacitada(s) aceitam as condições relativas ao uso de dados documentados através da WOCAT:

Sim

2.1 Descrição curta da tecnologia

Definição da tecnologia:

A combination of three measures to stabilise dunes: area closure, the use of palisades, and vegetative fixation through natural regeneration as
well as planting.

2.2 Descrição detalhada da tecnologia

Descrição:

In the Sahelian zone of Niger, sand dune encroachment can lead to loss of agricultural and pastoral land, and threatens villages. These dunes may form as a result of an increase in wind erosion, but more frequently originate from formerly stabilised dunes that have become mobile again following the disappearance of vegetation. Vegetation loss may occur through a combination of unfavourable climatic conditions and overexploitation by grazing and fuelwood gathering.

Purpose of the Technology: Sustainable dune fixation requires the regeneration of vegetation on the mobile parts of the dunes. For plants to establish, the dunes need to be protected by mechanical measures while being defended against any kind of use. Hence, the technique of dune stabilisation consists of a combination of three measures. These are as follows: (1) Area closure by wire fencing and guarding to prevent exploitation of the area during the rehabilitation phase until vegetation is sufficiently established (2-3 years). (2) Construction of millet stalk palisades arranged ideally in ‘checker-board’ squares, which act as windbreaks. These physical structures are a barrier to sand transport by wind, and thus are a prerequisite for revegetation. After two years the palisades fall apart and decompose - and the vegetation takes over the dune fixation function. Small erosion gullies can be controlled by check dams made from stone or millet stalks. (3) Natural regeneration, planting and seeding of annual and perennial plants (including Acacia spp. and Prosopis spp.) for soil stabilisation.

Establishment / maintenance activities and inputs: As soon as vegetation cover is established on the denuded surfaces the dunes can be used for grazing or for harvesting of herbs and fuelwood. Period and frequency of use should be determined in common agreement with all actors involved. In addition the pasture on the dune can be used as a ’reserve’ for late dry-season grazing, depending on vegetation development and herd size. Between 1991 and 1995, just over 250 ha of sand dunes were stabilised in the case study area. Incentives were provided by the ‘Projet de Développement Rural de Tahoua’ (PDRT, see also ‘Participatory land rehabilitation’ approach). After 1995 no further dunes were stabilised due to the high cost of the wire fencing, which local communities simply could not afford themselves. However, as the objective of the fence is to keep out humans and animals during critical periods (the rainy season), the same effect could be obtained at no financial cost through ‘social fencing’, that is agreement between stakeholders on where there should be no grazing. Furthermore the technology itself - which works well - could be relevant to situations where higher investment can be justified for specific reasons.

2.3 Fotos da tecnologia

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

2.7 Introdução da tecnologia

Especifique como a tecnologia foi introduzida:

• através de projetos/intervenções externas

3.1 Principal/principais finalidade(s) da tecnologia

• Reduz, previne, recupera a degradação do solo

• reduce loss of land

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

Comentários:

Major land use problems (compiler’s opinion): The area suffers from an imbalance between availability of natural resources (constrained by soil fertility and rainfall) and the rapid growth of the human and livestock populations. As a result, there is chronic food insufficiency and an associated overexploitation of the natural resource base. Accelerated wind and water erosion further enhance the degradation of the soil resources. From the farmers’ perspective, the main problems are lack of grazing land, wood and drinking water (due to sinking water tables), insufficient and unevenly distributed rainfall. Sand dunes are fragile: when overexploited, they soon remain with only unpalatable plant species, eg Panicum turgidum. When the vegetation cover on dunes decreases even further, dunes start moving again, threatening fields, villages or depressions used for fruit and vegetable cropping.

3.3 Mais informações sobre o uso da terra

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

• Precipitação natural

Especifique:

Longest growing period in days: 90; Longest growing period from month to month: Jul - Sep

3.4 Grupo de GST ao qual pertence a tecnologia

• Reserva ( suspensão do uso, apoio à recuperação)
• Solo/cobertura vegetal melhorada

3.5 Difusão da tecnologia

Comentários:

Total area covered by the SLM Technology is 2 km2.

3.6 Medidas de GST contendo a tecnologia

3.7 Principais tipos de degradação da terra abordados pela tecnologia

Comentários:

Main causes of degradation: droughts (manque de pluie; pluie mal répartie), land tenure, faim

Secondary causes of degradation: soil management (pas de jachère; pas suffisamment d'intrants. Mulching, engrais, mat. organique), deforestation / removal of natural vegetation (incl. forest fires) (combustibles), over-exploitation of vegetation for domestic use, overgrazing, population pressure (croissance de la population), poverty / wealth (Manque de moyens financiers), labour availability, education, access to knowledge and support services

3.8 Redução, prevenção ou recuperação da degradação do solo

Especifique o objetivo da tecnologia em relação a degradação da terra:

• Recuperar/reabilitar solo severamente degradado

4.1 Desenho técnico da tecnologia

4.2 Especificações técnicas/ explicações do desenho técnico

Sand dunes in the process of stabilisation: millet stalk palisades hinder detachment and displacement of sand particles through wind, and help vegetative cover to re-establish. Fences exclude animals during the restoration process.

Technical knowledge required for field staff / advisors: moderate

Technical knowledge required for land users: low

Main technical functions: improvement of ground cover, sediment retention / trapping, sediment harvesting, reduction in wind speed, stabilise sand dune surface, control detachment of particles by wind

Secondary technical functions: increase in organic matter

Agronomic measure: regenerated and seeded vegetation cover

Structural measure: millet stalk palisades

Structural measure: check dams (optional)

Change of land use practices / intensity level: area closure, controlled grazing

4.3 Informação geral em relação ao cálculo de entradas e custos

Especifique a moeda utilizada para os cálculos de custo:

• Dólares norte-americanos

4.4 Atividades de implantação

	Atividade	Tipo de medida	Periodicidade
1.	Construction of wire fence around the dune	Estrutural	December to June
2.	Palisade construction, 2000 m/ha.	Estrutural	December to June
3.	Guarding the fenced area	Gestão	all year round

4.5 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	Enclose area and protect	ha	1,0	300,0	300,0	100,0
Equipamento	Tools	ha	1,0	10,0	10,0
Material vegetal	Tree seedlings	ha	1,0	20,0	20,0
Material de construção	Wire fence	ha	1,0	1120,0	1120,0
Custos totais para a implantação da tecnologia					1450,0

Comentários:

Duration of establishment phase: 36 month(s)

In the Sahelian zone of Niger, wind erosion constitutes one of the major causes of land degradation. Measures to combat wind erosion and sand encroachment were developed through a rural development project. However in this case the cost was too high to justify continuation: nevertheless the technology itself may be applicable in other situations

4.6 Atividades recorrentes/manutenção

	Atividade	Tipo de medida	Periodicidade/frequência
1.	Harvesting of millet stalks , 2,000 bundles/ha (1 bundle = 6-10 kg).	Agronômico	October to February / initial establishment
2.	Seeding of herbaceous plants	Agronômico	May, just before rainy season / initial establishment
3.	Transplanting of locally available trees reared in a tree nursery	Agronômico	June to July, early rainy season / initial establishment
4.	Replanting of dead tree/shrub seedlings (20% replanting).	Agronômico	June to July /
5.	Guarding the area closure	Gestão	all year round /
6.	Controlled grazing once the dune has been stabilised: for periods of between 1 day and a week every 2 to 3 weeks – as determined	Gestão	/ between 1 day and a week every 2 to 3 weeks

4.7 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	Maintain area and guarding	ha	1,0	45,0	45,0	100,0
Material vegetal	Tree seedlings	ha	1,0	5,0	5,0
Custos totais para a manutenção da tecnologia					50,0

Comentários:

Labour (per ha, for establishment) includes installing wire fence (16 person days), collecting and transporting millet stalks and installing palisades (175 person days), sowing of herbaceous plants (2 person days), planting tree/shrub species (6 person days). Seedlings: under PDRT the tree nursery was financed by the project and the plants delivered to the ‘village’ - planting was done by the local population.

5.1 Clima

5.2 Topografia

5.3 Solos

Caso disponível anexe a descrição completa do solo ou especifique as informações disponíveis, p. ex. tipo de solo, PH/acidez do solo, nitrogênio, capacidade de troca catiônica, salinidade, etc.

Soil fertility is low

Soil drainage / infiltration is good

5.6 Características dos usuários da terra que utilizam a tecnologia

Indique outras características relevantes dos usuários da terra:

Off-farm income specification: due to out-migration of labour, commerce and also arts and crafts

5.7 Média da área de terra própria ou arrendada por usuários da terra que utilizam a tecnologia

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

Propriedade da terra:

• Comunitário/rural

Direitos do uso da terra:

• Acesso livre (não organizado)

6.1 Impactos no local mostrados pela tecnologia

Impactos socioeconômicos

Produção

Renda e custos

Outros impactos socioeconômicos

Impactos socioculturais

Impactos ecológicos

Solo

Clima e redução de riscos de desastre

Outros impactos ecológicos

6.2 Impactos externos mostrados pela tecnologia

Comentários relativos à avaliação de impacto:

Off-site benefits are difficult to assess and do not necessarily accrue to the local land users

6.4 Análise do custo-benefício

Como os benefícios se comparam aos custos de implantação (do ponto de vista dos usuários da terra)?

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

6.5 Adoção da tecnologia

Entre todos aqueles que adotaram a tecnologia, quantos adotaram espontaneamente, ou seja, sem receber nenhum incentivo material/pagamentos?

• 0-10%

Comentários:

There is no trend towards spontaneous adoption of the Technology

Comments on adoption trend: There is no spontaneous adoption as the technology is too expensive, labour intensive, and implemented on communal land.

6.7 Pontos fortes/vantagens/oportunidades da tecnologia

Pontos fortes/vantagens/oportunidades na visão do/a compilador/a ou de outra pessoa capacitada
Technically it is feasible to prevent dune encroachment and hence reduce the danger it exerts on arable/pastoral land and villages How can they be sustained / enhanced? Prevent overexploitation, apply SWC measures that are technically and financially feasible (eg use cheaper fencing material or ‘social fencing’).
Decrease loss of arable/pastoral land How can they be sustained / enhanced? Prevent overexploitation.
Additional income to the land user How can they be sustained / enhanced? Planting multipurpose tree/shrub species on the protected dunes, encourage pasture management systems eg rotational grazing.

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

Pontos fracos/vantagens/riscos na visão do/a compilador/a ou de outra pessoa capacitada	Como eles podem ser superados?
Soil cover is very sensitive to overexploitation	In order to increase acceptance, involve the whole community in the planning and management processes of the stabilised dune.
Social conflicts between farmers and herders due to area closure	In order to increase acceptance, involve all actors, including pastoralists or their representatives, in the planning and management process of the stabilised dune.
Use materials for the palisades that do not have an alternative use as fodder (as millet stalks do) for example twigs of Leptadenia pyrotechnica). Plastic nets exist for making palisades, but these are very expensive. Labour requirements difficult to circumvent.	Initiate the establishment of sustainable management systems eg communally managed rotational grazing systems.
Area closure to prevent exploitation of stabilised dunes means restricted access to potential grazing areas	Involved actors can agree upon a local convention that prohibits access during rehabilitation – ‘social fencing’ – and restricted exploitation after this phase. PDRT started to plant Euphorbia balsamifera within the fence with the idea of eventually removing and using it on another site.
High costs for fencing