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)

1.3 Condiciones referidas al uso de datos documentados mediante WOCAT

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

Sí

1.4 Declaración de la sostenibilidad de la Tecnología descrita

¿La Tecnología aquí descrita resulta problemática en relación a la degradación de la tierra, de tal forma que no puede considerársela una tecnología sostenible para el manejo de la tierra?

No

1.5 Referencia al (los) Cuestionario(s) de Enfoques MST (documentados usando WOCAT)

Community Organizations and Mobilization for Soil and Water … [Etiopía]

Community mobilization for soil and water conservation work in a watershed planning unit is an approach for collective action by organizing all active labor forces living in the kebele/peasant association into development group of 20-30 members and further divide into 1:5 work force to implement construction of soil and water …

• Compilador: Gizaw Desta Gessesse
• 14/03/2014 00:00

'Cut and Carry' Grazing system or 'Zero Grazing' … [Etiopía]

Cut and carry grazing system (alternatively called zero grazing) is an approach where the community is consulted to identify and agree on areas to be closed and protected from free grazing; establish user groups are established to share the fodder biomass harvested from communal closed areas equitably; they utilize tree/shrub …

• Compilador: Gizaw Desta Gessesse
• 16/05/2014 00:00

2.1 Breve descripción de la Tecnología

Definición de la Tecnología:

Vegetated graded soil bund is a soil conservation practice meant for cultivated lands and constructed by excavating graded channel on upper side and develop embankment on lower side which is planted with grass or shrub species in order to control soil erosion and drain excess runoff implemented through community mobilization.

2.2 Descripción detallada de la Tecnología

Descripción:

Vegetated graded soil bund is a practice or soil conservation technology for cultivated lands and constructed by excavating graded channel and form embankment. It is practiced in areas where there is excess runoff to be disposed and where there is no stones available for construction. The design specifications (ditch gradient, width and height) and layout (spacing/vertical interval) vary on the amount of excess runoff and slope of the land. Soil bund construction begins from top of the catchment. Cut off drains are constructed on top of the catchment and where needed to drain excess runoff to well stabilized natural or man-made waterways. this helps to reduce runoff impact on gullies. The bund ditch/channel should be sufficient enough to drain excess runoff safely without causing channel erosion and creating downstream damages. At same time the embankment should be stable to withstand overflows and damage due to free grazing. One technique to stabilize bunds is to plant the embankment with grass and shrub species of multiple economic value in order to compensate production area lost by bund construction. Often, the species are preferably used for livestock feed. Thus, free grazing has to be controlled. To protect damage of channels and embankments by extreme runoff and floods, frequent supervision and maintenance is required.

The purposes are:
1) Reduce nutrient loss and soil erosion by shortening the slope length,
2) Safely drain excess runoff from upstream of gully into protected waterways,
4) Produce biomass of fodder and cash values.

Vegetated graded bunds are established by doing surveying using hand level to determine the layout of the technology along the slope. During the surveying, the position of bunds (spacing) and cutoff drains and connection to waterways are determined. Bunds are laid following 0.05% gradient and up to 80 m maximum length. The specifications of the structure are: height of bund is a minimum of 60 cm after compaction; depending on the soil, base width range between 1.0 and 1.5m; top width is between 30 and 50 cm. The construction is made across different parcels owned by different land users. If there is no natural waterways and where it is appropriate, paved waterways are constructed at every 80 m or less bund length to dispose drainage water. At the beginning of the rainy season, the embankments are covered with grass and/or shrubs either by direct sowing of seeds or planting the seedlings raised in the nurseries. Monitoring of damages due to flooding and animals, maintenance of the structure as well as replanting of dead seedlings on bunds is required to sustain the soil conservation technology.

The technology is appropriately applied in high rainfall and sub-humid areas of the sub-tropics, particularly where the soil is moderately deep and poorly drained. It is constructed on cultivated lands having slopes in the range of 3-15%. The practice can be constructed by land users. It also requires collective decision and actions to drain excess runoff through waterways. The living condition depends on subsistence crop-livestock mixed farming. On average households have 5-6 family size. Crop production is meant for home consumption with small surplus for local market. The services related to water supply, energy supply, and infrastructure are low. Besides it is an asset, animals often used to cope shocks during drought periods.

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:

• hace menos de 10 años (recientemente)

2.7 Introducción de la Tecnología

Especifique cómo se introdujo la Tecnología:

• mediante proyectos/ intervenciones externas

Comentarios (tipo de proyecto, etc.):

The soil bunds are introduced before 30-40 years, however the integration of structural and combination of vegetative measures are applied in three years period in the WLRC learning watersheds.

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

Tierras cultivadas

• Cosecha anual
• Cultivos perennes (no leñosos)
• Cosecha de árboles y arbustos

• Rhamnus, Napier grass

• Cordia Africana, Polycantha, Sesbania Susban, Pigeon pea, Treelucer

Número de temporadas de cultivo por año:

• 1

Especifique:

Longest growing period in days: 210, Longest growing period from month to month: June-December; Second longest growing period in days: 180, Second longest growing period from month to month: June-November

Tierra de pastoreo

• free grazing

Comentarios:

Major land use problems (compiler’s opinion): Land degradation due to sheet erosion, rills and gullies, soil nutrient depletion, overgrazing, shortage of fuel wood, excessive removal of crop residuals, loss of vegetation and deforestation
Major land use problems (land users’ perception): Soil erosion, soil nutrient depletion, shortage of pasture

3.4 Provisión de agua

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

• totalmente irrigada

3.5 Grupo MST al que pertenece la Tecnología

• medida de pendiente transversal

3.6 Medidas MST que componen la Tecnología

medidas vegetativas

• V1: Cubierta de árboles y arbustos
• V2: Pastos y plantas herbáceas perennes

medidas estructurales

• S2: Taludes, bancos
• S3: Acequias graduadas, canales, vías fluviales

Comentarios:

Type of vegetative measures: aligned: -graded strips

3.7 Principales tipos de degradación del suelo encarados con la Tecnología

erosión de suelos por agua

• Wt: pérdida de capa arable/ erosión de la superficie
• Wo: efectos de degradación fuera del sitio

degradación del agua

• Hs: cambio en la cantidad de aguas superficiales

Comentarios:

Main causes of degradation: soil management (High tillage frequency on annual basis and steep slope cultivation), crop management (annual, perennial, tree/shrub) (The cropping system is cereal based that induce erosion), overgrazing (Livestock graze on crop residues after harvesting of crops), Heavy / extreme rainfall (intensity/amounts) (Extreme rainfall cause for high erosion), other natural causes (avalanches, volcanic eruptions, mud flows, highly susceptible natural resources, extreme topography, etc.) specify (Steep slopes or rugged topography), population pressure (Result in expansion of crop lands to steeper slopes)
Secondary causes of degradation: deforestation / removal of natural vegetation (incl. forest fires) (Deforestation of scattered trees in the farm and forests upstream of crop lands), land tenure (Insecure tenure play role not to invest on long term), poverty / wealth (Poor can not afford to invest on soil conservation on his parcel), education, access to knowledge and support services, governance / institutional

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:

• reducir la degradación del suelo

4.1 Dibujo técnico de la Tecnología

Especificaciones técnicas (relacionadas al dibujo técnico):

Vegetated graded soil bund showing the excavated ditch or channel and the embankment planted with grass and shrubs
Location: Amhara Region. Mecha, Yilmana Densa, Bahir Dar Zuria and Dessie Z

Technical knowledge required for field staff / advisors: high (Layout and design specification of soil bunds and cutoff drains vary on soil types, slopes, and rainfall conditions. Experts thus should acquire knowledge on specific hydrologic conditions)
Technical knowledge required for land users: moderate (Land users need skill to layout and construct bunds, monitor structures before the occurrence of excessive damage, and do regular maintenance)

Main technical functions: control of dispersed runoff: impede / retard, reduction of slope length, sediment retention / trapping, sediment harvesting, increase of biomass (quantity)
Secondary technical functions: control of dispersed runoff: retain / trap, reduction of slope angle, increase / maintain water stored in soil, increase of groundwater level / recharge of groundwater

Aligned: -graded strips
Vegetative material: T : trees / shrubs, C : perennial crops, G : grass
Number of plants per (ha): T=5333, C=160, G=1600
Vertical interval between rows / strips / blocks (m): 1-1.5
Spacing between rows / strips / blocks (m): 10-20
Vertical interval within rows / strips / blocks (m): T=0.3, C=5, G=0.5
Width within rows / strips / blocks (m): 0.3
Trees/ shrubs species: Cordia Africana, Polycantha, Sesbania Susban, Pigeon pea, Treelucer
Perennial crops species: Rhamnus
Grass species: Napier grass
Slope (which determines the spacing indicated above): 3-15%
Gradient along the rows / strips: 0.05%
Diversion ditch/ drainage
Depth of ditches/pits/dams (m): 0.3-0.7
Width of ditches/pits/dams (m): 1.2-2.8
Length of ditches/pits/dams (m): 100-250

Waterway
Depth of ditches/pits/dams (m): 0.3
Width of ditches/pits/dams (m): 1.5-2.0

Bund/ bank: graded
Vertical interval between structures (m): 1-1.5
Spacing between structures (m): 10-20
Depth of ditches/pits/dams (m): 0.5
Width of ditches/pits/dams (m): 0.3
Height of bunds/banks/others (m): 0.6
Width of bunds/banks/others (m): 1-1.5
Length of bunds/banks/others (m): 50-80

Construction material (earth): in-situ excavated soil
Slope (which determines the spacing indicated above): 3-15%
Lateral gradient along the structure: 0.05%
Vegetation is used for stabilisation of structures.

Autor:

Bekure Melesse, WLRC, P.O.Box 8707, Addis Ababa, Ethiopia

4.2 Información general sobre el cálculo de insumos y costos

otra / moneda nacional (especifique):

ETH BIRR

Si fuera relevante, indique la tasa de cambio de dólares americanos a la moneda local (ej. 1 U$ = 79.9 Reales Brasileros): 1 U$ =:

20,0

4.3 Actividades de establecimiento

4.4 Costos e insumos necesarios para el establecimiento

Comentarios:

Duration of establishment phase: 15 month(s)

4.5 Actividades de establecimiento/ recurrentes

4.6 Costos e insumos necesarios para actividades de mantenimiento/ recurrentes (por año)

Comentarios:

Machinery/ tools: Cart, plastic tubes, spade, pickaxe, hand level, graduated ranging pole, spade, pickaxe, crowbar, hammer
The costs are calculated based on the labour, seedling/seed, grass splits required per hectare

4.7 Factores más determinantes que afectan los costos:

Describa los factores más determinantes que afectan los costos:

The cost variation in implementing vegetated soil bund is dependent upon availability of stones, workability of the soil, cost of seeds or seedlings for plantation, and distance for transporting seedlings.

5.1 Clima

5.2 Topografía

5.3 Suelos

5.4 Disponibilidad y calidad de agua

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:

Land users applying the Technology are mainly common / average land users
Difference in the involvement of women and men: Women are involved in the construction of bunds with role of collecting stones, stabilize/compact the embankments and sometimes help men in excavating the earth
Population density: 200-500 persons/km2
Annual population growth: 2% - 3%
80% of the land users are average wealthy.
20% of the land users are poor.
Off-farm income specification: Land users often do not have access to off-farm income unless those who are young and own small size of land go for seasonal labor to towns during the slack period

5.7 Área promedio de la tierra usada 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

Derechos de uso de tierra:

• individual

Derechos de uso de agua:

• acceso abierto (no organizado)
• comunitarios (organizado)

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

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)

Extremos (desastres) relacionados al clima

Desastres climatológicos:

Desastres hidrológicos

Comentarios:

The technology has sufficient drainage ditch to tolerate excess runoff occurred during heavy rainfall events. However, it is sensitive to floods unless flood management measures such as strong cutoff drains and waterways are implemented

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:

The short term economic benefits of the technology includes increase in fodder production and slightly crop productivity due to improved soil moisture. Whereas the long term benefit can be obtained as a result of increased yield on areas where sediment accumulation occurs as well as production of fodder on soil bunds for livestock feed

6.5 Adopción de la Tecnología

Comentarios:

The technology is implemented using community mobilization approach which involves all land users. All land users, who cultivate land in areas where bunds are suitable, implemented the technology. All parcels are covered with the technology/bunds except homesteads and degraded hillsides and gullies which are treated with different SLM technologies
Since the approach encourages collective action (through community organizations) to integrate different SLM technologies in the watershed level, there is no attempt by individual land users. However, there are motivations and implementation of land users on adjacent watersheds to implement the technology.
There is a moderate trend towards spontaneous adoption of the Technology
The trend is at increasing rate although land users need material support such as multipurpose seedlings to stabilize bunds. There is shortage of supply of fodder seeds. Community nurseries are inadequate and not well supported to raise seedlings to meet community demands.

6.7 Fuerzas/ ventajas/ oportunidades de la Tecnología

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

7.1 Métodos/ fuentes de información

7.2 Vínculos a las publicaciones disponibles

Título, autor, año, ISBN:

Vegetated Graded Soil Bund: A Technique to Reduce Runoff Impact and Increase Soil Moisture Storage and Fodder Biomass, WLRC Brief No. 4

¿Dónde se halla disponible? ¿Costo?

WWW.wlrc-eth.org