Category: Stones no

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Negarim

Similar names: diamond-shaped micro catchment, V-shaped micro catchment, V-shaped bunds, Triangular bunds, small run-off basins

Negarim is an intervention that consists of small runoff micro basins characterised by a diamond shape, bound by low earth bundles. This water harvesting technique is mainly used for growing trees and bushes in arid and semi-arid areas but, as a side effect, it also preserves soil from erosion. It works great with rainfall rates starting from 150 mm/y and can be applied on slopes of up to 15%. This technique is more suitable for small-scale tree-planted areas and is pretty easy to create. Since Negarim mostly targets tree- and bush-planting, the area in which this technique is performed should be characterised by a soil depth of at least 1.5 metres, but preferably 2m. This is to ensure enough space for the roots to develop and for adequate storage of the water harvested.

The technique was originally developed in the Negev desert in Israel; in fact, the word Negarim comes from “Neger”, the Hebrew word for runoff. Nonetheless, the first report of this water harvesting technique comes from the south of Tunisia. This microcatchment system is widely spread in Israel, especially among research farms in the Negev desert where the yearly amount of rainfall reaches 100-150 mm. However, Negarim and its variations are well known, and used also, in other arid and semi-arid areas like in North- and Sub-Saharan Africa.

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Fanya Chini

Similar names: Retention trenches, infiltration trenches

The name Fanya chini means “throw it downwards” in Kiswahili. It consists of trenches and earthen ridges facing downslope. This intervention aims to reduce soil erosion by breaking down long slopes into smaller sections. Thus, the speed of runoff will decrease, and water can infiltrate into the soil between the bunds. This will result in a reduction of nutrient leaching and increased water availability for crops. Fanya chini is common in areas with 300-600 mm of annual rainfall on 1-25% slopes. It is suitable for all types of relatively permeable soils (e.g. alluvial, red, laterite, brown, and shallow and medium black soil). Still, it doesn’t work very well with clayey soils or vertisols as these are not permeable.

One of the main benefits of Fanya chini is that it limits soil erosion from water runoff, and simultaneously improves water retention in the soil and increases water availability for crops. Furthermore, an increase in yield is observed, as well as improved soil fertility.

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Zai Pits

Similar names: Chololo pits (Tanzania), Zaï pits (Burkina Faso), tassa (Niger), agun pits (Sudan), kofyarpits (Nigeria), yamka (Kyrgyzstan), planting pits.

Zai Pits are small basins in which the seeds of annual or perennial crops are planted. The pits are then filled with Mulch, manure, compost or good soils to increase soil fertility and the capacity of the soils to retain water. Zai Pits can be beneficial for soil conditions and they are a very successful method which can allow for the growth of vegetation in dry areas. They are also very efficient in protecting seeds and soil organic matter from being washed away from water runoff. One of the major advantages of Zai Pits is that it increases water filtration, through the collection and concentration of water for the plants due to increasing termite activity. What is more, Zai Pits can collect more than 25% or more of run-off water. This as a result decreases water run-offs and evaporation. When looking at the bigger picture, Zai Pits can improve soil fertility and agricultural productivity of several crops and can increase production by up to 500% if well executed.

Zai Pits are an efficient method to increase yield productivity due to more water and nutrients available. This intervention is most suitable for flat or gently sloped terrains (0-5%) with a precipitation range of 350-600 mm/y.  Zai Pits can also work with other techniques such as stone contours and hand-dug trenches.

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Farmer Managed Natural Regeneration

Similar names: tree recovery, natural regeneration, tree-based regeneration, Kisiki Hai

Natural regeneration is a biological process that can be assisted and managed by farmers and landowners to increase the recovery of native ecosystems and their functions. Usually practised on wooded agricultural land, Farmer Managed Natural Regeneration (FMNR) is an approach that aims to increase the number of trees by protecting, managing and pruning existing tree and shrub stumps and roots to create the optimal conditions for them to flourish and germinate seeds again. 

An advantage of FMNR is the freedom that farmers have in implementing and adapting this technique to their specific landscape. Farmers can make decisions based on their knowledge and experience and choose which tree species they want to target, for example, fruit trees. Farmers can also select which species they want to save or remove during the pruning process, as well as when and what preferred tree density they want.

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Conservation Agriculture

Similar names: No-Tillage Agriculture, No-Till Farming, Zero Tillage, Zlimate-Smart Agriculture

The Conservation Agriculture approach is a system of managing agricultural lands based on certain farming practices. It aims to achieve sustainable production through minimizing soil disruption, while preserving soil quality and improving its biodiversity. Indeed, the main goal of Conservation Agriculture is to tackle land degradation and increase efficiency in the use of water and nutrients. For this reason, this technique works well with degraded agro-ecosystems as it helps in the restoration of resources, and to increase profits and food security. Beside the conservation of soil structure and fertility, this practice plays an important role in preventing soil erosion caused by machineries, especially in hilly and mountainous areas.

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Mulching

Similar names: Covering, Groundcover, Topping, Blanket Mulching

Mulching involves applying a layer of material to the soil surface mainly in order to improve soil health and enhance plant growth. Either organic or inorganic materials can be used as mulch. Mulching simulates a natural forest environment. In a natural forest, soil is covered by leaves and organic material, and it is rich in living organisms that recycle nutrients. Mulch can be composed of a wide variety of materials (see method of application) and has a number of potential uses. It is an especially helpful technique in climactic zones with high evaporation rates. 

The physical and ecological benefits of Miyawaki are numerous. Firstly, the layer of mulch helps retain soil moisture by reducing the soil’s exposure to direct sunlight and preventing evaporation. Mulching is also effective at stifling weed growth by physically impeding their growth and stopping their access to sunlight needed for photosynthesis (amongst other mechanisms of weed prevention such as allelopathy with certain Mulching materials). Other benefits of Mulching include that it helps prevent soil erosion, is an effective means of regulating soil temperature by acting as insulation and improves the fertility and structure of soil (especially organic Mulching). Please refer to the conditions section for information on potential problems with Mulching so as to ensure the best chances of successful implementation.

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Tilling

Similair names: ploughing

Tilling is one of the most important and widely used agricultural techniques in the world. It dates back to ancient times. Tilling involves physically manipulating the soil to achieve optimal conditions for seed sowing and crop planting. Different tools and techniques for tilling agricultural land exist. Put simply, tilling consists of breaking, cutting, or turning over the first layer of soil (usually between 15 and 25 cm) before planting crops. This helps to achieve a range of potential benefits such as increased aeration of the soil, increased water infiltration capacity, improved nutrient availability, burying of leftovers of previous crops, and weed control. These effects provide good conditions for plant growth and root establishment. Although tilling aims to improve soil structure for planting crops, excessive tilling can have the opposite effect and create a detrimental impact on the soil by leading to a depletion of soil microorganisms and fertility. By loosening the soil, tilling also increases the vulnerability of land and soil to erosion.

Tilling offers several ecological and socioeconomic benefits. Ecologically, it improves soil aeration and drainage by breaking up compacted soil, facilitating better root growth and nutrient uptake, and aids in weed control by disrupting weed roots, reducing competition for resources. Socioeconomically, tilling enhances soil structure, creating a favourable seedbed for planting, which can boost crop yields and contribute to food security. It also accelerates nutrient cycling by decomposing organic matter and releasing nutrients back into the soil, reducing the need for chemical fertilizers. However, excessive tilling can lead to soil degradation and nutrient loss.

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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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Tree Islands

Similar Names: applied nucleation, cluster planting, Assisted Natural Regeneration, Tree Island Planting

Tree islands, also known as “applied nucleation” or “cluster planting”, are a forest restoration technique that combines tree planting and natural regeneration. The primary goal of tree islands is to restore degraded landscapes by accelerating natural forest regeneration. It involves the strategic planting of small clusters of trees (“tree islands”), creating focal points for ecosystem restoration and accelerating natural regeneration in between the islands. They enhance natural forest recovery, rely on animal species for the dispersal of native tree seeds, and promote high levels of native biodiversity. 

The tree islands act as biodiversity hotspots, improving soil fertility, water retention, and microclimate, creating resilient ecosystems. They increase the availability of tree seeds and attract seed dispersers. They also provide shade, suppressing sun-loving plants that can overgrow in the area,  leaving no space for trees to establish. By creating tree islands, a base is offered from which the forest can re-establish itself and grow back much faster than conventional natural regeneration approaches.

Overall, tree islands represent an innovative and promising approach to forest restoration, offering a sustainable method for accelerating the recovery of temperate, tropical, and subtropical forests. It is a cost-effective forest restoration technique that uses only about 20% of the trees that would be needed for a whole forest plantation of the same area. This makes it more accessible and the structure more natural.

When implementing this intervention in a certain area, it is best to involve the community. It can even become a community-driven initiative, with community members working on the implementation, monitoring, and maintenance of the tree islands. This enables them to play an active role in local forest regeneration.