Category: Land use: Grazing & Rangeland

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Gully Rehabilitation Stem Cuttings

Similar names: Gully Plugging with Stem Cuttings, Check Dams from Stem Cuttings, Brushwood Check Dams, Live Check Dams

Gully Rehabilitation Stem Cuttings is an intervention that “plugs” particularly active gullies and streams by building Check Dams made of Stem Cuttings to control erosion and runoff. These living barriers are efficient in slowing down runoff water and stopping sediment buildup in the gullies. Field research has proven that they work well in soils of sandy/loamy texture, where the performances of these dams are greater than ones made of stone dams due to rooted poles and the stabilised root system of the living barrier.

Stem Cuttings involve taking sections of woody stems from suitable plants and inserting them into the soil in a gully or erosion-prone area. These stems will develop roots and grow into new plants, helping to stabilize the soil and prevent further erosion. Stem Cuttings are cost-effective and environmentally friendly, promoting natural vegetation growth, and enhancing biodiversity, and ecosystem health. They also provide erosion control once established, preventing further degradation of the gully.

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Contour Bunds

Similar names: Level Bunds, Contour Stone Bunds, Earthen Bunds, Contour Bunding

Contour Bunds are a form of micro-catchment technique and are a very simple and cheap form of water control. The bunds are created along the contour lines. There are also small earth ties, perpendicular to the bunds, that subdivide the system into micro-catchments. Contour Bunds are very similar to Negarim in that they aim to slow down runoff and improve water infiltration in the soil. For this reason, Contour Bunds are often associated with the cultivation of crops, fodder or trees which are grown between the bunds. Contour Bunds also help to control soil erosion. Contour Bunds for tree planting is suitable in arid and semi-arid areas with rainfall rates between 200 and 750 mm. They can be applied on slopes of up to 5% but they require even terrains, without the presence of gullies or rills. The soil should preferably be 1.5 to 2 m deep in order to ensure proper root development and water storage.

Contour Bunds are also a cost-effective nature-based solution, which is relatively cheap, especially on a larger scale and on even lands because less earth is moved. The intervention could be combined with machinery, which additionally enables the technique to be scaled up to larger areas. Finally, fodder crops can be grown before the trees become productive, which as a result could lead to a reduction in the amount of runoff that can reach the trees.

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Swales

A swale is an intervention designed to retain water run-off on a slope. It is a long, small ditch on the contour lines, i.e. at the same elevation. Several swales can be constructed next to each other to increase their effect. Swales have a small berm on the downslope side, which often contains vegetation and acts as a retaining wall.

Swales are cost-effective and relatively easy to implement, preventing soil erosion, nutrient run-off, and flooding. They capture water which runs down the hill and let it infiltrate into the soil. Growing vegetation on the berm will strengthen the berm and the soil and will hold water and nutrients better. Trees, in particular, work well for strengthening berms and are watered by the water held by the swales. If possible, it is also an option to add stones to a berm to make it even stronger. In the Perma Atlas Initiative, swales have been a great success in preventing flooding. Swales are similar to Contour Bunds and Fanya Chini and they can be used on a small or large scale. The greatest reduction observed when swales are introduced are in water runoff, soil loss, phosphorus runoff and nitrate-nitrogen runoff.

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Gabions

Similar names: Riprap, Gabion Baskets

Gabions are metal baskets filled with stones. Gabions act as retaining walls and will mitigate the effects of heavy rainfall, which is accelerating due to climate change. They can be placed in streams and gullies to slow the flow of water and prevent flooding. If the water is not slowed down, the topsoil is washed away and erosion worsens. With the topsoil gone, there are no nutrients left, making the soil unsuitable for vegetation and water absorption. Gabions will hold this and prevent erosion and further degradation. Moreover, the Gabion allows water to pass through while trapping soil particles. Where possible, the community should be involved as Gabions play a role in protecting their communities and land. Gabions can also be used for coastal protection and slope stability. Sometimes they are also used for aesthetic purposes.

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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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Silvopasture

Similar names: silvopastoral system, mixed pastures.

Silvopasture is a technique that integrates trees and shrubs with the keeping of grazing livestock on the same piece of land. Silvopasture interventions aim to realise the benefits of combining two systems: grazing animals help to keep weeds away from trees and fertilise the soil with manure, while trees (often fruit trees) provide additional fodder for the livestock through their extra leaves/biomass. Silvopastoral systems are used as an alternative to conventional cattle farming systems to combat deforestation problems.

This intervention is traditionally applied in tropical and temperate zones but also in subhumid, semiarid, and arid regions. Some other variations are agro-silver-pastures, which combine trees or shrubs, wish crops and cattle. A more complex system should be well planned but that can bring a variety of benefits. Also called the crop-livestock-forest system (CIF). Another alternative is silver fishery, which combines woody perennials and fish resources.

Silvopasture offers numerous ecological benefits, including improved water management by reducing runoff and increasing retention, which prevents soil erosion and landslides. It enhances soil quality and nutrient content, supports carbon sequestration through tree planting, and boosts biodiversity by introducing trees that provide habitats for various species. Additionally, it reduces the risk of fire by controlling understory vegetation and improves livestock conditions by providing shade, which can increase their lifespan and milk yield. Economically, silvopasture lowers costs by using livestock for weed control, diversifies income sources through harvesting trees and livestock products, and enhances food security and sustainability for farming communities. It also supports indigenous livelihoods by preserving traditional knowledge and culture.

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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)