Category: Land use: Agricultural

Posted on

Dune Fencing

Building semi-permeable fences along the seaward or the prevailing wind side of dunes encourages windblown sand to accumulate, reduces trampling, and protects both existing and newly planted vegetation. Various fencing materials can effectively enhance natural dune recovery. This type of fencing is often combined with other management practices to promote dune stabilization and minimize environmental impact.

The use of dune fencing for wind erosion control and dune stabilization has a long history. Its success relies on factors such as the fence’s void-to-solid ratio, the availability of wind-driven sand, the frequency of wave activity at the fence line, and the amount of vegetation present to help stabilize accumulated sand. Combining dune fencing with other strategies, such as Dune Planting or Dune Thatching, can help establish new foredunes and further enhance stability.

Posted on

Muvuca Direct Seeding

Similar names: Seed-based land restoration, Direct sowing

Muvuca direct seeding is a nature restoration method, where a mix of seeds from dozens of native species at different successional stages are planted simultaneously into the ground. The method mimics natural regeneration mechanisms such as seed soil banks and seed rain. Better known conventional practice is direct seeding’s popular counterpart – transplanting, which is a technique of moving plants from one location to another, usually to preserve the optimal condition of the seedlings. Despite providing more control over the plant’s growth, transplanting doesn’t allow for a high variety of plant seeds to grow simultaneously.

The Muvuca system uses a high diversity of species and ensures longer-term operational efficiency, which in return enables mechanised restoration with reduced planting, low maintenance in terms of time and reduced costs. Planting can be done either manually or mechanised (using machinery such as tractors), which enables the scalability of the intervention. Furthermore, the grown plants through Muvuca become more robust and resistant to various weather conditions, which results in stronger root systems and overall healthier vegetation. Overall, Muvuca direct seeding can contribute to the scaling up of restoration efforts, while reducing costs and increasing the species diversity. Meanwhile, the demand for native species enables the promotion of conservation and well-being.

Posted on

Composting

Similar names: Organic Amendments

Composting is an effective method of organic waste management, involving the controlled aerobic decomposition of organic matter, such as plant and animal waste. This process results in Compost, a stable, humus-like material that can be directly applied to soil. The primary goal of Composting is to reduce the amount of organic waste sent to landfills while providing economic, environmental, and social benefits. When used in soil, Compost enriches it, reducing the need for chemical fertilizers and lowering potential methane emissions from landfills.

The Composting process (Source)

Due to its recycling nature, Composting is a cost-effective tool for managing organic waste, utilizing leftover materials from land-based processes. It offers a range of co-benefits that enhance land and soil regeneration practices. Agronomically, Composting supports crop yields, improves soil moisture content and workability, enhances crop nutritional quality, and suppresses weeds, pests, and diseases. Additionally, Composting provides broader environmental benefits by supplying essential nutrients (such as mineralized nitrogen, phosphorus, and potassium), reducing soil erosion, sequestering carbon, and improving soil biological properties and biodiversity.

Furthermore, Compost can be used as a mulching material in landscaping, garden management, and the restoration of abandoned quarries, among other applications.

Agricultural benefits of Composting (Source)

Posted on

Assisted Natural Regeneration

Similar names: Pruning, Kisiki Hai, Managed Regrowth

Assisted Natural Regeneration (ANR) is a simple, low-cost forest restoration method that can effectively convert deforested and degraded lands into productive forests and rangelands. The method uses a blend of active planting and passive restoration techniques, which help vegetation to naturally recover by eliminating barriers and threats to their growth. ANR is similar to Farmer-Managed Natural Regeneration (FMNR), with the difference that ANR applies to degraded forest lands and rangelands while FMNR is usually practised on croplands. Overall, ANR mimics the natural systems and habitats by supporting the land processes through ANR. 

ANR is a flexible restoration approach and could be adapted to various contexts and objectives. A set of ecosystem restoration techniques are being facilitated, to eliminate obstacles to plant growth and survival. Those could vary depending on a range of factors, such as location, land type, restoration goal, etc. Hence, local community engagement is crucial for successfully implementing and managing ANR. Their knowledge of the land and ancestral traditions offers the best indication of what techniques and practices would be most beneficial. The most common ANR techniques are visualized in the figure below.

(source)

In comparison to other regeneration techniques such as tree-planting campaigns, ANR has comparatively low implementation and maintenance costs. The method could be applied on a local and larger scale level, with some areas and contexts being more favorable than others when it comes to implementation (see Requirements). However, where implemented, ANR can create jobs and bring income to local communities, as the implementations would require establishment and maintenance.

Posted on

Stone Lines

Similar names: Cordons pierreux, stone bunds.

Stone lines are stones grouped in the shape of a line and placed along contours. The stones can be of different sizes. The goal of these lines is to conserve the soil and reduce runoff, as they are used to slow down water runoff and break its velocity. Hence, they increase infiltration and retain sediment and seeds to make water and nutrients available for crops. Stone lines are most suitable for water harvesting on slightly sloping plains (up to 5%) in semi-arid regions. For slopes starting from 5%, stone bunds can be used (see eyebrow terraces).

Stone lines are an easy and cheap intervention if stones are available in the immediate surroundings. This intervention is widely used in Africa, both in dry and humid areas. Moreover, stone lines are often used in combination with Zai Pits intervention for the rehabilitation of degraded and crusted lands. It is applied in semi-arid areas, on sandy and loamy soils where the slope is lower than 5%. A great example can be seen in Niger, where the combination of the two techniques is applied to capture runoff, making infiltration more efficient and improving nutrient availability. The pits have a diameter of 20-30 cm, and a depth of 20-25 cm and are spaced about 1 m apart in each direction. Stone lines are spaced 20-25 m apart on slopes of 2-5%. With this layout stone lines are quite small, usually, three stones wide and only one stone high and they are placed, along the contour lines, by hand. Very often grass grows between the stones leading to a greater infiltration and helping the accumulation of fertile sediments. Maintenance-wise, stone lines need to be repaired annually, in particular after heavy precipitation events.

Posted on

Terracing

Terracing is a method of farming and soil conservation on hills and sloped lands. It was traditionally used by the Incas and is widely practised around the world today. It involves the building of platforms, and forming step-like structures along a slope. The main goal of bench terraces is to periodically interrupt the slope of the terrain with flat sections; this helps to decrease the speed of water runoff,  significantly reducing soil erosion and surface runoff. By slowing down water speed, this intervention stops the washing away of topsoil containing important nutrients and promotes better water infiltration and soil moisture. The flat benches of the terraces create more effective and productive areas to farm on steep terrain.

There are two main types of terracing techniques: graded terracing and level terracing. With graded terracing, the slope can vary along the length of the terrace to direct water in the desired direction; this is especially useful for less permeable land. With level terracing, the terraces follow a contour line and do not vary in slope along this line, this ensures that water is more evenly distributed along the terrace. Stone or wooden walls are often used to hold terraces in place, although a simple earth wall without supporting material can be used with slopes and terraces on the smaller side. This intervention is similar to Fanya Juu and Fanya Chini which are specific types of terraces.

Terracing offers several ecological and socioeconomic benefits. Ecologically, it prevents soil erosion by slowing water flow, allowing it to infiltrate the soil and retain valuable topsoil, which is essential for agriculture. Terracing also manages water more effectively by evenly distributing it across levels, conserving water, reducing irrigation needs, and promoting nutrient cycling. It creates diverse habitats for various plant and animal species, enhancing biodiversity. Additionally, terracing stabilizes slopes, reducing the risk of landslides by minimizing soil pressure and movement, especially in regions with wet seasons. Socioeconomically, terracing increases land productivity on slopes, allowing for larger crop beds and easier use of machinery, thus boosting agricultural efficiency.

Posted on

Vegetative Lines

Vegetative lines involve the planting of lines of vetiver grass following the contour lines, along stream banks and roadsides, to create a hedge. These hedges act like semi-permeable barriers, aimed to hinder surface erosion as they slow down run-off and retain sediments picked up by excess rainwater. This setup improves water infiltration and helps to increase the ground moisture level. Their root systems also help stabilise the soil and prevent further soil erosion. Thus this provides increased stabilisation of embankments, gully erosion, roads and slopes. Furthermore, water runoff and soil runoff reductions are observed, at around 57% and 80% respectively.

Vetiver grass can grow on slopes of > 50% and can be planted on a high variety of soils (red latosols, black cracking vertisols, roadside rubble, C-horizon gravels, laterites, sodic, and saline soils). Furthermore, vetiver grass is resistant to different types of climatic conditions: rainfall from 600mm to 6000 mm /year and extreme temperatures of -14°C to 55°C, and could survive several months submerged in water. Vetiver grass can support high levels of toxicity by manganese, aluminium and other metals and high levels of soil acidity, salinity, alkalinity, and acid sulphate conditions. All in all, they provide great solutions as they are non-invasive, fire resistant, and regrow quickly and be used as mulch, fuel (vetiver energy value is 55% the energy value of coal), and as fodder. Finally, vetiver grass is very efficient in stabilising Semi-Circular Bunds, Eyebrow Terraces or Negarim.

Very similar to the intervention described above is the so-called “Vegetative lines with cactus”. This intervention is based on the same principle as the Vegetative lines with vetiver grass, but it is suitable for drier environmental conditions (0 – 600mm). Like some other interventions, over time, this type of intervention can lead to the formation of terraces due to tillage and water erosion between the hedges.

Posted on

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.

Posted on

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.

Posted on

Fanya Juu

Similar names: Terracing, Retention Trenches, Infiltration Trenches

The Fanya Juu technique is an agricultural practice that involves creating ridges along the contour lines of sloping land. The name Fanya Juu means “throw it upwards” in Kiswahili and is very similar to Fanya Chini as it consists of terrace bunds and ditches along the contour. This technique rapidly spread during the 1970s and 1980s and it is well known throughout Eastern Africa, the goal of Fanja Juu contour bunds is different depending on the environmental conditions of the areas within which they are applied. Their aim in semi-arid areas is to harvest and conserve rainfall, whereas, in sub-humid zones, contour bunds are constructed to discharge excess runoff. However, their main purpose is to prevent water and soil loss and to make conditions more suitable for plants to grow. 

Fanya Juu is suitable for slopes of 5-20%, similar to the ones that characterize Fanya Chini interventions. The species most often used in drier zones are Pennisetum Purpureum (Napier grass or Uganda grass) and Panicum Coloratum (also known in southern Africa as “white buffalograss”) and the harvest can be used as fodder for livestock. Fruit trees (e.g. citrus or bananas) can be planted either immediately above the embankment or below the ditch, where runoff tends to concentrate.