Category: Goal: Prevent erosion

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Grass Seed Banks

Similar names: Community Seed Banks (also for other seeds)

Grass Seed Banks are a conservation and restoration strategy aimed at revitalizing degraded landscapes, particularly in arid and semi-arid regions. Communities can decide where they are suitable and establish them in degraded areas of about ten hectares. Grass Seed Banks are sowed with grass seedlings and should be naturally fenced using shrubs to protect the grasses against grazing livestock and wildlife. These seed banks serve as repositories of native grass seeds, which are essential for restoring vegetation cover in areas affected by desertification, land degradation, and biodiversity loss. They are a community-based initiative that restores degraded landscapes and provides economic opportunities for local communities, especially women. Grass Seed Banks can be managed and maintained by local women’s groups, who sow and harvest the grand grass seeds. Once the grasses are fully grown, they produce grass seeds, which the women can sell at local markets (for example to other restoration projects) or as fodder for livestock.

By selling the grass seeds, women can earn additional income. When grass seed bank projects are successful, the status of the women in the community can be improved. Selling the grass seeds can also help other restoration projects and thereby help to regreen other areas as well. Moreover, they can help to attract insects and small animals, which boosts local biodiversity and the growth of vegetation in the area around the seed banks.

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Fencing

Fencing around eroded soils, rills and gullies is a cheap and low-maintenance form of sediment catchment, soil and water runoff prevention on gentle, moderate and steep slopes. Three types of fencing are detailed in this intervention about their prevention of different types of soil erosion at varying topographies.

  1. Silt Fences → Softer intervention for sediment catchment, preventing runoff and wind displacement on rills, arid fields or gentle hillsides. 
  2. Woven Fences → Harder intervention for slope stabilisation and sediment build-up in gullies and rocky mountainous landscapes.
  3. Biotrampas → Harder intervention for rock catchment, landslides and slope stabilisation in gullies and heavily eroded, steep mountainous landscapes.
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Alley Cropping

Similar names: Alley Farming, Nalaad, Intercropping, Farming with Shade Trees

Alley Cropping is a farming method whereby trees and shrubs are planted in rows, and crops are grown in the spaces between these rows. This technique helps reduce soil erosion by slowing down water runoff and increasing water absorption capacity of the soil. The trees protect crops from strong winds, provide habitats for wildlife, and attract pollinators such as bees. Planting different species of trees or shrubs can bring additional benefits as they may be harvested to provide fodder for animals, food, firewood, or materials for mulching.

Farmers can start Alley Cropping on a small scale by planting hedgerows around their fields or farms. On larger farms, the distance between the rows can be increased to enable the use of machinery. Common crops used for Alley Cropping include corn, soybeans, wheat, and potatoes. Often, these crops are combined with trees that produce valuable products like hardwood timber or nuts. This technique is flexible and can be adapted to meet the specific needs of any farm, making it a practical way to improve productivity and sustainability.

NOTE: This method works particularly well in humid and semi-humid regions, but has also been successful in dry areas when undertaken with careful planning. In drier regions, it is important to ensure that hedgerows do not compete with crops for soil moisture.

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Miyawaki Forest

Similar names: Tiny Forests, Fast Growing Forests, Urban Forests, Potential Natural Vegetation

The Miyawaki method is a reforestation technique that entails the growing of a forest within a few decades – instead of centuries – by taking into account the succession of plants and plant diversity that naturally occurs in forests. This method was first conceptualised in Japan by Dr. Akira Miyawaki and has been successfully implemented in areas with relatively high rainfall rates such as India, Malaysia, and South America. However, it has also been successfully practised in other/locations/, such as the Mediterranean; the steppe zone of Jordan; and the Persian Gulf region.

This technique is particularly effective as it imitates the structure of a mature forest. It aims at recreating all the different levels of vegetation and combinations of species that would naturally occur in a native forest without human intervention – defined as “potential natural vegetation”. Practitioners must carefully select the right indigenous vegetation best adapted to local conditions, and they need to commit to watering and mulching the seedlings during the first years of implementation of the intervention. One of the advantages of using this technique is that it allows for the quick regrowth of a dense forest rich in biodiversity which can retain rainfall and create a cooling microclimate effect. Furthermore, the maintenance is comparatively low, as the forest becomes self-sufficient after 3 years.

NOTE: The implementation of this technique can be expensive as it requires a lot of seedlings for a relatively small area. However, it allows to obtain a fully functional forest in a short time, with minimal maintenance needed.

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Charco Dams

Charco Dams are a traditional means of water harvesting in arid and semi-arid landscapes of Eastern Africa, especially in Tanzania. This type of dam has a deep reservoir and limited surface area which helps to reduce water-loss from evaporation. Charco Dams are built to collect rainwater and runoff water from flat surfaces. As a result, they are suitable for livestock watering and crop irrigation, but less suitable for domestic use (unless the water is treated). Typically, trees and shrubs are planted around the edges of the dam to act as windbreaks to further reduce evaporation. Small earth dams may vary significantly in size based on the water storage capacity needed. Storage of up to 1000m3 is possible, beyond which a pond is considered large and will require different building protocols. Dams need to be thoroughly planned in order to ensure their feasibility, longevity, and safety. Please make sure to consult the additional supporting resources provided for more specific details on how to plan and build a Charco Dam, or talk to a local extension officer for help on planning and implementing a Charco Dam in your landscape.

Picture by: Rikolto (Vredeseilanden)