Nardi/Vallerani trenches [Níger]
- Criação:
- Atualização:
- Compilador/a: Dieter Nill
- Editor: –
- Revisor: Deborah Niggli
Tranchées Nardi (French)
technologies_1613 - Níger
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Expandir tudo Recolher tudo1. Informação geral
1.2 Detalhes do contato das pessoas capacitadas e instituições envolvidas na avaliação e documentação da tecnologia
Nome do projeto que facilitou a documentação/avaliação da Tecnologia (se relevante)
Good Practices in Soil and Water Conservation - A contribution to adaptation and farmers ́ resilience towards climate change in the Sahel (GIZ)Nome da(s) instituição(ões) que facilitou(ram) a documentação/ avaliação da Tecnologia (se relevante)
Deutsche Gesellschaft für Internationale Zusammenarbeit (GIZ) GmbH (GIZ) - Alemanha1.3 Condições em relação ao uso da informação documentada através de WOCAT
Quando os dados foram compilados (no campo)?
01/07/2012
O/a compilador/a e a(s) pessoa(s) capacitada(s) aceitam as condições relativas ao uso de dados documentados através da 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 de gestão sustentável de terra?
Não
2. Descrição da tecnologia de GST
2.1 Descrição curta da tecnologia
Definição da tecnologia:
Nardi/Vallerani trenches are microcatchments which are made using a special tractor-pulled plough to restore degraded and encrusted forests and rangelands
2.2 Descrição detalhada da tecnologia
Descrição:
Nardi/Vallerani trenches are microcatchments 4 m long and 0.5 m wide. They are made using a tractor-pulled plough specifically designed for this purpose. The Nardi plough cuts a furrow perpendicular to the slope, throwing up a ridge on the downhill side and thereby creating a barrier on that side of the furrow. The number of trenches varies according to the gradient of the terrain and the type of soil: the recommended number of microcatchments for flat or gently sloping terrain is between 250 and 400 per hectare, with the rows spaced 5 to 7 m apart; and for steeper slopes, the rows should be spaced 3 to 4 m apart, with a density of up to 600 microcatchments per hectare. In each Nardi/Vallerani microcatchment, two or three trees are planted or sown by direct seeding and then separated when they come up. Perennial grasses are sown a year later to allow the trees to become established first. The choice of species largely depends on the use to which the improved land is to be put and the priorities of the beneficiaries. It is recommended that the improved site be protected from grazing animals for at least three years to give the trees time to grow and the grass time to reproduce naturally, although the exact amount of time required will depend on the type of trees planted and how degraded the site is.
Nardi/Vallerani trenches are generally combined with scarification, which is carried out using a tractor-pulled scarifier. The strips between the trenches are scarified a year after they have been dug. These scarified strips are sown with perennial grasses at the same time as the trenches. The trees planted the year before are a year old, and the risk of the saplings being choked by the grass is minimal.
Runoff collects in the Vallerani microcatchments, improving the infiltration of water into the soil and the retention of water for the plants growing in them. They also serve to loosen the soil and improve the plants’ access to nutrients. Windborne seeds are trapped in the microcatchments, which helps to build up the natural grass cover.
This technique is particularly effective when rainfall is low, as the microcatchments retain water and make it available to the plants growing in them.
In the medium term, this technique is effective in protecting the land against water and wind erosion and rehabilitating barren land with no vegetation. In wet years, the microcatchments protect the land downhill from excessive run- off by retaining part of the water.
Implemented on a wide scale, this technique can extend and improve the quality of forest and rangeland and reduce the problems for livestock keepers in years when the quality of pasture is not good. In the medium and long- term, the technique can increase the supply of firewood, timber and other wood products. Even in the short term, it increases the production of straw, which can be used as forage, for making roofing and mats or sold to generate extra income.
Establishment / maintenance activities and inputs: In order to ensure the sustainability of the investment, it is necessary to take the following steps before constructing the trenches: ensure that the communities are motivated to invest in the measure; ensure that the communities have the capacity to do the work and the technical expertise required to implement the measures and develop and manage the sites; ensure that there are sufficiently strong local and regional markets for forest/rangeland products; clearly define the objective (intended uses after improvement); clarify ownership of the land to be improved; jointly define who the beneficiaries will be; formulate an agreement establishing rules governing the protection, use and upkeep of the site.
The right grass species must be chosen to ensure the successful establishment of vegetation cover, taking the following factors into consideration: needs of livestock keepers and/or agro-pastoralists; species suited to environmental conditions, taking into account climate changes; palatability and nutritive value of the species and any secondary uses they may have; availability of seeds; potential for marketing products.
The Sahel is a region where the population has always faced a high degree of climate variability, manifested both in terms of time (unexpected dry spells can occur during the rainy season) and in terms of space (rainfall can vary greatly from one area to another). The population is mainly composed of small farmers and livestock keepers.
Over the last two decades, the effects of climate change have exacerbated the already difficult conditions. Accord¬ing to projections made by climatologists, the Sahel will experience a rise in temperatures combined with highly variable rainfall and an increase in extreme weather events.
The Soil and Water conservation and rehabilitation techniques have helped people in the Sahel to manage their ecosystems more effectively and improve their productive land. As a result, communities are better prepared to cope with environmental changes (changes in the climate, land degradation, etc.) and the im¬pact of shocks, particularly droughts
2.3 Fotos da tecnologia
2.5 País/região/locais onde a tecnologia foi aplicada e que estão cobertos nesta avaliação
País:
Níger
Região/Estado/Província:
Niger
Especificação adicional de localização:
Regions of Tillabéri, Filingué, Ouallam, Téra and Tahuoa
Map
×2.6 Data da implementação
Caso o ano exato seja desconhecido, indique a data aproximada:
- 10-50 anos atrás
2.7 Introdução da tecnologia
Especifique como a tecnologia foi introduzida:
- através de projetos/intervenções externas
Comentários (tipos de projeto, etc.):
developed, implemented and disseminated as part of projects and programmes undertaken from the 1980s onwards to combat desertification and improve natural resource management. Implemented by GIZ (German Federal Enterprise for International Cooperation), PDRT (Projet de développement rural de Tahoua - Tahoua Rural Development Project), PASP (Projet de protection intégrée des ressources agro-sylvo-pastorales Tillabéri-Nord - Project for the Integrated Protection of Agricultural, Forest and Rangeland Resources in Tillabéri-Nord)
3. Classificação da tecnologia de GST
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 extensiva:
- Seminomadismo/pastoralismo
Pastagem intensiva/produção de forragem:
- Semiestabulação/sem pastagem
Floresta/bosques
Florestas/bosques (semi)naturais:
- Derrubada seletiva
Produtos e serviços:
- Madeira
- Lenha
- Frutas e nozes
- Outros produtos florestais
- Pastagem/Alimentação de folhas e brotos
Comentários:
Major land use problems (compiler’s opinion): crusting, surface runoff, water and wind erosion, unadapted land use methods, rapidly growing population increasing pressure on land, reduced or abandoned fallow periods, insecure access to land.
Farmers are mainly agropastoralists with some communities specialised on pure pastoralism
Constraints of forested government-owned land or commons
3.3 Mais informações sobre o uso da terra
Abastecimento de água para a terra na qual a tecnologia é aplicada:
- Misto de precipitação natural-irrigado
Número de estações de cultivo por ano:
- 1
Especifique:
Longest growing period in days: 120, Longest growing period from month to month: August to October
Densidade animal (se relevante):
1-10 LU /km2
3.4 Grupo de GST ao qual pertence a tecnologia
- Solo/cobertura vegetal melhorada
- Perturbação mínima ao solo
- Medidas de curva de nível
3.6 Medidas de GST contendo a tecnologia
Medidas vegetativas
- V1: cobertura de árvores/arbustos
- V2: gramíneas e plantas herbáceas perenes
Medidas estruturais
- S4: Valas de nível, fossos
3.7 Principais tipos de degradação da terra abordados pela tecnologia
Erosão do solo pela água
- Wt: Perda do solo superficial/erosão de superfície
- Wo: efeitos de degradação externa
Erosão do solo pelo vento
- Et: Perda do solo superficial
Deteriorização química do solo
- Cn: declínio de fertilidade e teor reduzido de matéria orgânica (não causado pela erosão)
Deteriorização física do solo
- Pc: Compactação
- Pk: quebra e ressecamento
Degradação biológica
- Bc: redução da cobertura vegetal
Degradação da água
- Ha: aridificação
Comentários:
Main causes of degradation: soil management (Unadapted land use methods, reduced or abandoned fallow periods), crop management (annual, perennial, tree/shrub) (Neglect of fallow periods and crop rotation), droughts (due to heat waves), population pressure (rapidly growing population increasing pressure on land), land tenure (insecure access to land and collectively managaed commons), poverty / wealth (very poor population)
Secondary causes of degradation: deforestation / removal of natural vegetation (incl. forest fires) (deforestation through overgrazing and fire wood collection), over-exploitation of vegetation for domestic use (firewood collection), overgrazing (cattle, shee and goats), change in temperature (Climate change: heat waves), change of seasonal rainfall (more variable onset of rain), Heavy / extreme rainfall (intensity/amounts) (more variable and intensive rains), wind storms / dust storms (frequent storms), floods (due to intensive rains), labour availability (some migration of men to nearby cities), education, access to knowledge and support services (high level of illiteracy)
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
4.2 Especificações técnicas/ explicações do desenho técnico
Nardi/Vallerani trenches are microcatchments 4 m long and 0.5 m wide. The Nardi plough cuts a furrow perpendicular to the slope, throwing up a ridge on the downhill side and thereby creating a barrier on that side of the furrow. The recommended number of microcatchments for flat or gently sloping terrain is between 250 and 400 per hectare, with the rows spaced 5 to 7 m apart; and for steeper slopes, the rows should be spaced 3 to 4 m apart, with a density of up to 600 microcatchments per hectare.
Source of drawing: Ministère du Développement Agricole Niger (without date): Recueil des fiches techniques en gestion des ressources naturelles et de productions agro-sylvo-pastorales.
Location: Niger
Technical knowledge required for field staff / advisors: high
Technical knowledge required for land users: moderate
Main technical functions: control of dispersed runoff: retain / trap, control of dispersed runoff: impede / retard, control of concentrated runoff: retain / trap, control of concentrated runoff: impede / retard, improvement of ground cover, improvement of surface structure (crusting, sealing), improvement of topsoil structure (compaction), increase of infiltration, increase / maintain water stored in soil, water harvesting / increase water supply
Secondary technical functions: stabilisation of soil (eg by tree roots against land slides), increase in nutrient availability (supply, recycling,…), sediment retention / trapping, sediment harvesting, reduction in wind speed, promotion of vegetation species and varieties (quality, eg palatable fodder)
Vegetative measure: within each microcatchment 2-3 trees
Vegetative material: T : trees / shrubs, G : grass
Number of plants per (ha): 700-1250
Vegetative measure: Vegetative material: T : trees / shrubs, G : grass
Retention/infiltration ditch/pit, sediment/sand trap
Spacing between structures (m): 5-7
Depth of ditches/pits/dams (m): 0.4
Width of ditches/pits/dams (m): 0.5
Length of ditches/pits/dams (m): 4
Vegetation is used for stabilisation of structures.
4.3 Informação geral em relação ao cálculo de entradas e custos
Outro/moeda nacional (especifique):
CFA Franc
Indique a taxa cambial do dólar norte americano para a moeda local (se relevante): 1 USD =:
521,18
4.4 Atividades de implantação
Atividade | Tipo de medida | Periodicidade | |
---|---|---|---|
1. | The Nardi plough cuts a furrow perpendicular to the slope, throwing up a ridge on the downhill side and thereby creating a barrier on that side of the furrow | Estrutural | |
2. | In each Nardi/Vallerani microcatchment, two or three trees are planted or sown by direct seeding | Vegetativo |
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 | labour | ha | 1,0 | 16,3 | 16,3 | 100,0 |
Equipamento | machine use | ha | 1,0 | 23,6 | 23,6 | 100,0 |
Equipamento | transport and planting trees | ha | 1,0 | 12,3 | 12,3 | 100,0 |
Material vegetal | seedlings | ha | 1,0 | 52,0 | 52,0 | 100,0 |
Custos totais para a implantação da tecnologia | 104,2 |
4.6 Atividades recorrentes/manutenção
Atividade | Tipo de medida | Periodicidade/frequência | |
---|---|---|---|
1. | Separating trees when they come up | Vegetativo | |
2. | Perennial grasses are sown a year after the trees to allow the trees to become established first. | Vegetativo | |
3. | The strips between the trenches are scarifieda year after they have been dug. These scarified strips are sown with perennial grasses at the same time as the trenches. | Vegetativo |
4.7 Custos e entradas necessárias pata a manutenção/atividades recorrentes (por ano)
Comentários:
Microcatchments on low-gradient terrain
• 1 Nardi plough (imported from Italy)
• tractor hire.
Labour
• 8.5 man-days per ha.
Other costs
• 800 seedlings and 15 kg of seeds (plus transport and replacement plants).
4.8 Fatores mais importantes que afetam os custos
Descreva os fatores mais determinantes que afetam os custos:
The slope determines the costs. The number of trenches varies according to the gradient of the terrain and the type of soil: the recommended number of microcatchments for flat or gently sloping terrain is between 250 and 400 per hectare, with the rows spaced 5 to 7 m apart; and for steeper slopes, the rows should be spaced 3 to 4 m apart, with a density of up to 600 microcatchments per hectare.
5. Ambiente natural 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
Zona agroclimática
- Semiárido
Thermal climate class: subtropics
5.2 Topografia
Declividade 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 s.n.m.
- 101-500 m s.n.m.
- 501-1.000 m s.n.m.
- 1.001-1.500 m s.n.m.
- 1.501-2.000 m s.n.m.
- 2.001-2.500 m s.n.m.
- 2.501-3.000 m s.n.m.
- 3.001-4.000 m s.n.m.
- > 4.000 m s.n.m.
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)
- Fino/pesado (argila)
Matéria orgânica do solo superficial:
- Médio (1-3%)
5.4 Disponibilidade e qualidade de água
Lençol freático:
5-50 m
Disponibilidade de água de superfície:
Médio
Qualidade da água (não tratada):
apenas para uso agrícola (irrigação)
5.5 Biodiversidade
Diversidade de espécies:
- Baixo
5.6 Características dos usuários da terra que utilizam a tecnologia
Orientação de mercado do sistema de produção:
- Subsistência (autoabastecimento)
- Misto (subsistência/comercial)
Rendimento não agrícola:
- 10-50% de toda renda
Nível relativo de riqueza:
- Muito pobre
- Pobre
Nível de mecanização:
- Trabalho manual
- Tração animal
Gênero:
- Homens
Indique outras características relevantes dos usuários da terra:
Population density: 10-50 persons/km2
Annual population growth: 3% - 4% (mostly poor households below poverty line).
Off-farm income specification: men migrate temporarily or permanently to cities for off-farm income, women and men seasonally carry out paid farm work
5.7 Média da área de terra própria ou arrendada por usuários da terra que utilizam a tecnologia
- < 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
É considerado pequena, média ou grande escala (referente ao contexto local)?
- Pequena escala
5.8 Propriedade de terra, direitos de uso da terra e de uso da água
Propriedade da terra:
- Estado
- Comunitário/rural
Direitos do uso da terra:
- Acesso livre (não organizado)
- Comunitário (organizado)
Direitos do uso da água:
- Acesso livre (não organizado)
- Comunitário (organizado)
Comentários:
traditional land use rights prevail. On fields individual land use rights, communal land on pasture and forest land (collection of wood and other products (fruits, medicinal plants))
5.9 Acesso a serviços e infraestrutura
Saúde:
- Pobre
- Moderado
- Bom
Educação:
- Pobre
- Moderado
- Bom
Assistência técnica:
- Pobre
- Moderado
- Bom
Emprego (p. ex. não agrícola):
- Pobre
- Moderado
- Bom
Mercados:
- Pobre
- Moderado
- Bom
Energia:
- Pobre
- Moderado
- Bom
Vias e transporte:
- Pobre
- Moderado
- Bom
Água potável e saneamento:
- Pobre
- Moderado
- Bom
Serviços financeiros:
- Pobre
- Moderado
- Bom
6. Impactos e declarações finais
6.1 Impactos no local mostrados pela tecnologia
Impactos socioeconômicos
Produção
Produção de forragens
Qualidade da forragem
Produção animal
Comentários/especificar:
It is recommended that the improved site be protected from grazing animals for at least three years to give the trees time to grow and the grass time to reproduce naturally
Produção de madeira
Área de produção
Renda e custos
Rendimento agrícola
Outros impactos socioeconômicos
amount of straw (used as forage or sold and/or used for roofing, doors and fencing)
Impactos socioculturais
Segurança alimentar/auto-suficiência
Atenuação de conflitos
contribution to human well-being
Comentários/especificar:
Implemented on a wide scale, this technique can extend and improve the quality of forest and rangeland and reduce the problems for livestock keepers in years when the quality of pasture is not good. In the medium and long-term, the technique can increase the supply of firewood, timber and other wood products. Even in the short term, this technique increases the production of straw, which can be used as forage, for making roofing and mats or sold to generate extra income. The forest/rangeland sites help communities to bridge the hunger gap, and in lean years, the women collect forest products, such as leaves, pods and fruit to supplement their diet. Sometimes, small quantities of wood are sold to buy cereals. Ingredients for medicinal products and other secondary products, such as gum arabic, are collected from the trees and bushes.
Impactos ecológicos
Ciclo hídrico/escoamento
Colheita/recolhimento de água
Escoamento superficial
Solo
Umidade do solo
Cobertura do solo
Perda de solo
Ressecamento/ selagem do solo
Compactação do solo
Ciclo e recarga de nutrientes
Biodiversidade: vegetação, animais
Biomassa/carbono acima do solo
Quantidade anterior à GST:
100 kg/ha
Quantidade posterior à GST:
540 kg/ha
Diversidade vegetal
Clima e redução de riscos de desastre
Velocidade do vento
6.2 Impactos externos mostrados pela tecnologia
Cheias de jusante
Sedimentos transportados pelo vento
6.3 Exposição e sensibilidade da tecnologia às mudanças climáticas graduais e extremos/desastres relacionados ao clima (conforme o ponto de vista dos usuários da terra)
Mudança climática gradual
Mudança climática gradual
Estação do ano | Tipo de mudança climática/extremo | Como a tecnologia lida com isso? | |
---|---|---|---|
Temperatura anual | aumento | bem |
Extremos (desastres) relacionados ao clima
Desastres meteorológicos
Como a tecnologia lida com isso? | |
---|---|
Temporal local | não bem |
Tempestade de vento local | bem |
Desastres climatológicos
Como a tecnologia lida com isso? | |
---|---|
Seca | bem |
Desastres hidrológicos
Como a tecnologia lida com isso? | |
---|---|
Inundação geral (rio) | não bem |
Comentários:
Physical structures can be biologically stabilized through planting of grass, bushes or trees. Damages are generally small but need to be repaired quickly.
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:
positivo
Retornos a longo prazo:
muito 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:
muito positivo
Comentários:
In the short term, this technique increases the production of straw, which can be used as forage, for making roofing and mats or sold to generate extra income. In the medium and long-term, the technique can increase the supply of firewood, timber and other wood products.
6.5 Adoção da tecnologia
Comentários:
The techniques were implemented with food for work in the 1990s to 2000. At the end, the work provided by land users was not compensated. Only small equipment and transportation were provided for free. Some adoption (without support by the project) has been observed in some places.
There is a little trend towards spontaneous adoption of the Technology. Some adoption (without support by the project) has been observed in some places.
6.7 Pontos fortes/vantagens/oportunidades da tecnologia
Pontos fortes/vantagens/oportunidades na visão do/a compilador/a ou de outra pessoa capacitada |
---|
In the medium term, this technique is effective in protecting the land against water and wind erosion and rehabilitating barren land with no vegetation. |
Runoff collects in the Vallerani microcatchments, improving the infiltration of water into the soil and the retention of water for the plants growing in them. They also serve to loosen the soil and improve the plants’ access to nutrients. Windborne seeds are trapped in the microcatchments, which helps to build up the natural grass cover. |
In wet years, the micro-catchments protect the land downhill from excessive runoff by retaining part of the water. |
This technique is particularly effective when rainfall is low, as the microcatchments retain water and make it available to the plants growing within them. |
The average additional output of dry matter in the form of herbaceous biomass was approximately 540 kg/ha, compared with less than 100 kg per hectare on land where the technique was not applied |
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? |
---|---|
Animal production is reduced because the improved site should be protected from grazing animals for at least three years to give the trees time to grow and the grass time to reproduce naturally | |
Vallerani microcatchments are recommended for use on well-structured soils (soils with high clay content and lateritic and stony soils). On poorly structured soils (sandy, silty soils), the furrows tend to close over after the first rains, rendering them ineffective. | |
The Acacia holosericea species is not considered suitable for reforestation purposes, owing to its limited life span. |
7. Referências e links
7.1 Métodos/fontes de informação
- visitas de campo, pesquisas de campo
- entrevistas com usuários de terras
7.2 Referências às publicações disponíveis
Título, autor, ano, ISBN:
Good Practices in Soil and Water Conservation. A contribution to adaptation and farmers´ resilience towards climate change in the Sahel. Published by GIZ in 2012.
Disponível de onde? Custos?
http://agriwaterpedia.info/wiki/Main_Page
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