1.2 Detalles de contacto de las personas de referencia e instituciones involucradas en la evaluación y la documentación de la Tecnología

Nombre del proyecto que financió la documentación/ evaluación de la Tecnología (si fuera relevante)

Programme d’Appui à l’agriculture Productive (GIZ / PROMAP)

Nombre de la(s) institución(es) que facilitaron la documentación/ evaluación de la Tecnología (si fuera relevante)

Deutsche Gesellschaft für Internationale Zusammenarbeit (GIZ) GmbH (GIZ) - Alemania

Nombre de la(s) institución(es) que facilitaron la documentación/ evaluación de la Tecnología (si fuera relevante)

Misereor - Alemania

1.3 Condiciones referidas al uso de datos documentados mediante WOCAT

¿Cuándo se compilaron los datos (en el campo)?

01/07/2012

El compilador y la/s persona(s) de referencia claves aceptan las condiciones acerca del uso de los datos documentados mediante WOCAT:

Sí

2.1 Breve descripción de la Tecnología

Definición de la Tecnología:

Hand-dug trenches contribute to the restoration of tree cover and prevention of water erosion on slopes.

2.2 Descripción detallada de la Tecnología

Descripción:

This technique is designed to restore communal land on slopes and highland pediments. It involves manually excavating trenches 3 to 3.5 m long and 0.6 m deep, spaced 4 m apart in staggered rows. This results in around 625 trenches per hectare. The excavated earth is piled downhill of the trenches, which are aligned perpendicular to the slope. In the middle of each trench, a 0.40 m high step is left on which the tree seedling is planted. The tree receives the water it needs from the trench where it collects.

Purpose of the Technology: The main purpose of this technique is to restore tree cover on degraded, unfertile land and prevent water erosion on slopes by reducing the flow of water that threatens land downstream. The trenches reduce gully erosion and pedimentation of areas with a fragile soil structure. Like all afforestation measures, in the medium term, this technique is effective in protecting the land against water and wind erosion. The shade provided by the trees also lowers the temperature of the soil and the infiltration of water in the hand-dug trenches contributes to groundwater recharge.
Areas restored using hand-dug trenches can subsequently be exploited to a limited extent in accordance with strict controls.

Establishment / maintenance activities and inputs: The technique is very labour intensive. Work must begin immediately after harvesting when the soil is still moist and workable. A protection and monitoring system is required to ensure that grazing animals do not damage the young trees. The mortality of trees after planting is relatively high (survival rate is about 60%), and dead trees must be replaced systematically during the first three years. Good community organisation is required.

Natural / human environment: Hand-dug trenches are particularly useful when rainfall is low, as they retain water and make it available to the trees growing in them. In years when rainfall is abundant or there are violent downpours, the young trees are protected, as they are planted on a raised step within the trench, although there is a risk of flooding in the event of very heavy rain.

2.3 Fotografías de la Tecnología

2.5 País/ región/ lugares donde la Tecnología fue aplicada y que se hallan comprendidos por esta evaluación

2.6 Fecha de la implementación

Si no se conoce el año preciso, indique la fecha aproximada:

• 10-50 años atrás

2.7 Introducción de la Tecnología

Especifique cómo se introdujo la Tecnología:

• mediante proyectos/ intervenciones externas

Comentarios (tipo de proyecto, 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 German Development Cooperation (BMZ, GIZ, KfW) in Niger by projects e.g. PDRT (Projet de développement rural de Tahoua - Tahoua Rural Development Project)

3.1 Propósito(s) principal(es) de la Tecnología MST

• reducir, prevenir, restaurar la degradación del suelo

3.2 Tipo(s) actuales de uso de la tierra donde se aplica la Tecnología

Comentarios:

Major land use problems (compiler’s opinion): water erosion (gully, sheet), wind erosion, degraded and infertile land

Nomadism: Yes

Semi-nomadism / pastoralism: Yes

Cut-and-carry/ zero grazing: Yes

Improved pasture: Yes

Mixed: (eg agro-pastoralism, silvo-pastoralism): Yes

Other grazingland: agropastoralism

Selective felling of (semi-) natural forests: Yes

Forest products and services: timber, fuelwood, fruits and nuts, grazing / browsing, other forest products / uses (honey, medical, etc.)

Type of cropping system and major crops comments: armers are mainly agropastoralists with some communities specialised on pure pastoralism

Constraints of common grazing land

Constraints of forested government-owned land or commons

3.3 Información adicional sobre el uso de tierras

Provisión de agua para la tierra donde se aplica la Tecnología:

• de secano

Comentarios:

Water supply: Also mixed rainfed - irrigated and post-flooding

Número de temporadas de cultivo por año:

• 1

Especifique:

Longest growing period in days: 120; Longest growing period from month to month: August to October

Densidad del ganado (si fuese relevante):

1-10 LU /km2

3.4 Grupo MST al que pertenece la Tecnología

• cobertura de suelo/ vegetal mejorada
• Manejo de irrigación: (incl. provisión de agua, invernaderos)

3.5 Difusión de la Tecnología

Especifique la difusión de la Tecnología:

• distribuida parejamente sobre un área

3.6 Medidas MST que componen la Tecnología

3.7 Principales tipos de degradación del suelo encarados con la Tecnología

Comentarios:

Secondary types of degradation addressed: Et: loss of topsoil, Hg: change in groundwater / aquifer level

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 managed communal land), 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, sheep and goats), change in temperature (Climate change: heat waves), change of seasonal rainfall (more variable onset of rains), Heavy / extreme rainfall (intensity/amounts) (more variable and intensive rains), wind storms / dust storms (frequent storms), floods (due to intensive rain storms), labour availability (some migration of men to nearby cities), education, access to knowledge and support services (high level of illiteracy)

3.8 Prevención, reducción o restauración de la degradación del suelo

Especifique la meta de la Tecnología con relación a la degradación de la tierra:

• restaurar/ rehabilitar tierra severamente degradada

Comentarios:

Secondary goals: prevention of land degradation, mitigation / reduction of land degradation

4.1 Dibujo técnico de la Tecnología

4.2 Especificaciones técnicas/ explicaciones del dibujo técnico

Trenches are manually excavated 3 to 3.5 m long and 0.6 m deep, spaced 4 m apart in staggered rows. This results in around 625 trenches per hectare. The excavated earth is piled downhill of the trenches, which are aligned perpendicular to the slope. In the middle of each trench, a 0.40 m high step is left on which the tree seedling is planted. The tree benefits from the water collected in the trench.

Technical knowledge required for field staff / advisors: moderate

Technical knowledge required for land users: low

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, control of concentrated runoff: drain / divert, improvement of ground cover, stabilisation of soil (eg by tree roots against land slides), increase of infiltration, increase / maintain water stored in soil, water harvesting / increase water supply

Secondary technical functions: increase in organic matter, increase in nutrient availability (supply, recycling,…), increase of groundwater level / recharge of groundwater, sediment retention / trapping, sediment harvesting, reduction in wind speed, increase of biomass (quantity), promotion of vegetation species and varieties (quality, eg palatable fodder)

Vegetative measure: planted in trench
Vegetative material: T : trees / shrubs, G : grass

Vegetative measure: Vegetative material: T : trees / shrubs, G : grass

Retention/infiltration ditch/pit, sediment/sand trap
Spacing between structures (m): 4
Depth of ditches/pits/dams (m): 0.6
Length of ditches/pits/dams (m): 3.5

Vegetation is used for stabilisation of structures.

4.3 Información general sobre el cálculo de insumos y costos

Especifique la moneda usada para calcular costos:

• dólares americanos

4.4 Actividades de establecimiento

	Actividad	Tipo de medida	Momento
1.	marking out the contour line	Estructurales
2.	laying out the trenches in staggered rows	Estructurales
3.	digging two rectangular microcatchments separated horizontally by a flat surface	Estructurales
4.	making a hole in the central area	Vegetativas
5.	planting the seedlings	Vegetativas
6.	sowing grass on the ridges	Vegetativas

4.5 Costos e insumos necesarios para el establecimiento

	Especifique insumo	Unidad	Cantidad	Costos por unidad	Costos totales por insumo	% de los costos cubiertos por los usuarios de las tierras
Mano de obra	All the Labour	unit	1,0	220,76	220,76
Material para plantas	Seedlings	unit	1,0	41,55	41,55
Otros	Transport of seedlings	unit	1,0	1,93	1,93
Costos totales para establecer la Tecnología					264,24

4.6 Actividades de establecimiento/ recurrentes

	Actividad	Tipo de medida	Momento/ frequencia
1.	A protection and monitoring system is required to ensure that grazing animals do not damage the young trees	Vegetativas
2.	dead trees must be replaced systematically during the first three years	Vegetativas

4.8 Factores más determinantes que afectan los costos:

Describa los factores más determinantes que afectan los costos:

Other costs
• equipment, such as jumper bars, shovels and axes
• 625 tree seedlings
• 15 kg of grass seed
• cost of transporting 2 cartloads of seedlings
• 120 seedlings to replace dead trees.

5.1 Clima

5.2 Topografía

Comentarios y especificaciones adicionales sobre topografía :

Altitudinal zone: 200 m a.s.l.

Landforms: Also footslopes and valley floors

5.3 Suelos

Si se halla disponible, adjunte una descripción completa de los suelos o especifique la información disponible, por ej., tipo de suelo, pH/ acidez de suelo, capacidad de intercambio catiónico, nitrógeno, salinidad, etc. :

Soil fertility is very low - medium

Soil drainage / infiltration is poor - medium

Soil water storage capacity is low - medium

5.4 Disponibilidad y calidad de agua

Comentarios y especificaciones adicionales sobre calidad y cantidad de agua:

Ground water table: > 10m

Availability of surface water: Surface runoff generated by limited but intense rainfalls

5.5 Biodiversidad

5.6 Las características de los usuarios de la tierra que aplican la Tecnología

Indique otras características relevantes de los usuarios de las tierras:

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

Market orientation of production system: Most households crop for subsistence , but surplus is sold on the market. Some vegetable growing is just for commercial/ market.

Level of mechanization: Oxes and donkeys used for animal traction.

5.7 Área promedio de la tierra que pertenece a o es arrendada por usuarios de tierra que aplican la Tecnología

5.8 Tenencia de tierra, uso de tierra y derechos de uso de agua

Tenencia de tierra:

• estado
• comunitaria/ aldea

• not titled

Derechos de uso de tierra:

• individual

Comentarios:

Traditional land use rights prevail. On fields individual land use rights, communal rights on pasture and forest land (collection of wood and other products (fruits, medicinal plants))

5.9 Acceso a servicios e infraestructura

6.1 Impactos in situ demostrados por la Tecnología

Impactos socioeconómicos

Producción

Ingreso y costos

Impactos socioculturales

Impactos ecológicos

Ciclo de agua/ escurrimiento de sedimento

Suelo

Biodiversidad: vegetación, animales

Reducción de riesgos de desastres y riesgos climáticos

6.2 Impactos fuera del sitio demostrados por la Tecnología

6.3 Exposición y sensibilidad de la Tecnología al cambio climático gradual y a extremos relacionados al clima/ desastres (desde la percepción de los usuarios de tierras)

Cambio climático gradual

Cambio climático gradual

	Estación	tipo de cambios climáticos/ climas extremos	¿Cómo es que la tecnología soporta esto?
temperatura anual		incrementó	bien

Extremos (desastres) relacionados al clima

Desastres climatológicos:

	¿Cómo es que la tecnología soporta esto?
tormenta de lluvia local	no muy bien
tormenta de viento	bien

Desastres climatológicos

	¿Cómo es que la tecnología soporta esto?
sequía	bien

Desastres hidrológicos

	¿Cómo es que la tecnología soporta esto?
inundación general (río)	no muy bien

Otras consecuencias relacionadas al clima

Otras consecuencias relacionadas al clima

	¿Cómo es que la tecnología soporta esto?
periodo reducido de crecimiento	no se sabe

Comentarios:

Damages are generally small but need to be repaired quickly.

6.4 Análisis costo-beneficio

¿Cómo se comparan los beneficios con los costos de establecimiento (desde la perspectiva de los usuarios de tierra)?

¿Cómo se comparan los beneficios con los costos de mantenimiento/ recurrentes (desde la perspectiva de los usuarios de tierra)?

Comentarios:

Establishment of the trenches involves considerable labour and growth of trees takes a couple of years.

6.5 Adopción de la Tecnología

De todos quienes adoptaron la Tecnología, ¿cuántos lo hicieron espontáneamente, es decir, sin recibir incentivos/ pagos materiales?

• 0-10%

Comentarios:

Comments on acceptance with external material support: The technology has been applied by PDRT on common land using food/cash for work in order to inject money and food into the local communities.

Comments on spontaneous adoption: There was no spontaneous adoption. The technology is designed for common lands and takes considerable labour that only very well organised communities are able to mobilise.

There is no trend towards spontaneous adoption of the Technology

6.7 Fuerzas/ ventajas/ oportunidades de la Tecnología

Fuerzas/ ventajas/ oportunidades desde la perspectiva del usuario de la tierra
The young trees are protected of flooding, as they are planted on a raised step within the trench

Fuerzas/ ventajas/ oportunidades desde la perspectiva del compilador o de otra persona de referencia clave
Hand-dug trenches retain water and make it available to the trees growing in them. Although the trenches are progressively filled with sediment, which reduces their capacity to retain water, at the same time, the trees develop and become less dependent on stored water.
This technique has proved effective in restoring forest/rangeland sites. The progressive development of grass and tree cover continues on the improved sites, where the tree population is up to 20 years old. After around ten years, the average annual production of wood is 1.3 steres per hectare.
The shade provided by the trees also lowers the temperature of the soil.
In the medium term, this technique is effective in protecting the land against water and wind erosion.
Areas restored using hand-dug trenches can subsequently be exploited to a limited extent in accordance with strict controls.

6.8 Debilidades/ desventajas/ riesgos de la Tecnología y formas de sobreponerse a ellos

Debilidades/ desventajas/ riesgos desde la perspectiva del compilador o de otra persona de referencia clave	¿Cómo sobreponerse a ellas?
The technique is very labour intensive. Work must begin immediately after harvesting when the soil is still moist and workable.	Good community organisation is required.
A protection and monitoring system is required to ensure that grazing animals do not damage the young trees. The mortality of trees after planting is relatively high (survival rate is about 60%), and dead trees must be replaced systematically during the first three years.

7.3 Vínculos a la información relevante disponible en línea

Título/ descripción:

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.

URL:

http://agriwaterpedia.info/wiki/Main_Page