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Changing Harvest Time

Value Chain
Climatic Zone
Decision Making
Farming Characteristics
Mechanisation
Labour Intensity
Initial Investment
Maintenance Costs
Access to Finance/Credit
Extension Support Required
Access to Inputs
Access to Markets
Gender/Youth Smart
Description

Changing harvest time refers to adjusting harvest time to focus on optimal moisture conditions, thereby avoiding losses from mould, decay and possible disease, while also considering optimal maturity of the crop. This approach encourages the reduction in potential losses of ripened grain and increases potential higher quality grain for consumption or market. Harvesting of crops when physiologically mature can minimise losses during transportation to the homestead. Physiological harvesting refers to the time when a grain (fruit, etc.) can be separated from its parent plant and continues to ripen over time. Farmers should consider planting earlier or later or consider planting faster or slower maturing varieties to avoid issues of post-harvest loss. This is a climate smart practice because it reduces potential losses of ripened grain, increase the quality of grain harvested, and is overall a more efficient use of resources, all while mitigating the spread of diseases and reducing GHG emissions.

Technical Application

To effectively implement Changing Harvest Time practices:

  • Step 1: Consider researching recent rainfall records and consult national meteorological services to as accurately predict start of rainy season as possible.
  • Step 2: Farmers should consult data provided by the African Post Harvest Loss Information System (APHLIS), which provides information on harvest loss and additional resources to consult.
  • Step 3: Consult with national agricultural extension and research to determine growing periods of chosen crops. Request information about quicker or slower maturing seeds.
  • Step 4: Plant crops at the right time so as to avoid harvesting during rainy season.
  • Step 5: Harvest as soon as crops are physiologically mature.
  • Step 6: Wait 24 hours after a rain period to harvest if rain is unavoidable. This may take several days, however, harvesting crops after one rain is better than leaving it for an entire rainy season.
  • Step 7: Crops should be transported to the storage for immediate drying.
Return on Investment Realisation Period
Crop Production
Fodder Production
Farm Income
Household Workload
Food Security
Soil Quality/Cover
Biological Diversity
Flooding
Crop/Livestock Water Availability
Wind Protection
Erosion Control
Increase Production
Reduces potential losses of ripened grain.
Increase Resilience
More grain of a higher quality to consume and sell.
Mitigate Greenhouse Gas Emissions
More efficient use of resources.
Additional Information
PDF File
/sites/secondsite/files/tb/CCARDESATechnicalBrief_37_ChangingHarvestTime_2019-10-17_0.pdf
Benefits and Drawbacks

Benefits

  • Reduces the potential loss of ripened grain and increases potential higher quality grain for consumption or market.
  • It improves crop production, food security and farm income.

Drawbacks

  • Moisture from rainfall at harvest time can risk crop degradation post-harvest, due to mould, decay and disease.
  • Different crops have different growing seasons, and this should be known and monitored constantly, specifically as climate change has been shown to alter growing seasons, which will in turn impact harvesting times.

Best Practice Harvesting Techniques

Value Chain
Climatic Zone
Decision Making
Farming Characteristics
Mechanisation
Labour Intensity
Initial Investment
Maintenance Costs
Access to Finance/Credit
Extension Support Required
Access to Inputs
Access to Markets
Gender/Youth Smart
Description

Best Practice Harvesting Techniques are formalised harvesting practices intended to reduce breakage and bruising of crops during collection and storage. These techniques minimise harvest losses and maintain the quality of the produce. To maximise this approach, factors such as moisture content, cleanness of the grain, colour, odour and potential pest infestation need to be considered during harvest periods. Considering each of these factors will increase grain value as quality standards are directly related to grain price. Harvesting can be performed manually or mechanically, with obvious cost implication of employing the latter.

Technical Application

To effectively implement Best Practice Harvesting Techniques:

  • Step 1: Obtain equipment and supplies needed for the harvest and post-harvest activities, e.g. clean sacks, drying mats, etc.
  • Step 2: Allocate drying and threshing areas, ensuring the areas are swept, dry, and there is no/limited access for livestock or rodents. If in a dry climate or season, drying outside is optimal. If necessary, construct drying cribs elevated from the ground with rodent guards on legs can reduce access for rodents.
  • Step 3: Allocate sufficient storage space for the harvested crop.
  • Step 4: Clear weeds from the farm to prevent weed seeds from contaminating the harvest.
  • Step 5: Place the harvested crop directly onto clean mats and bags to avoid contact with the soil, which may lead to moisture uptake and also prevent contamination with tiny Striga.
Return on Investment Realisation Period
Crop Production
Fodder Production
Farm Income
Household Workload
Food Security
Soil Quality/Cover
Biological Diversity
Flooding
Crop/Livestock Water Availability
Wind Protection
Erosion Control
Increase Production
Reduces potential losses of ripened grain.
Increase Resilience
More grain of a higher quality to consume and sell.
Mitigate Greenhouse Gas Emissions
More efficient use of resources.
Additional Information
PDF File
/sites/secondsite/files/tb/CCARDESATechnicalBrief_36_BestPracticeHarvestingTech_2019-10-17_0.pdf
Benefits and Drawbacks

Benefits

  • Best practice harvesting techniques improve grain quality and minimise post-harvest loses.

Drawbacks

  • Lodging can cause significant losses as well as contamination.

Farmer Managed Natural Regeneration

Value Chain
Climatic Zone
Water Source
Decision Making
Farming Characteristics
Mechanisation
Labour Intensity
Initial Investment
Maintenance Costs
Access to Finance/Credit
Extension Support Required
Access to Inputs
Access to Markets
Gender/Youth Smart
Description

Farmer Managed Natural Regeneration (FMNR) is a technique of restoring degraded land and monitoring restoration of the land involving the systematic regeneration and management of trees and shrubs from tree stumps, roots and seed. Degraded arid land often features left over indigenous plants, which if maintained and promoted to grow can improve pasture and crop lands while simultaneously encouraging re-growth of seeds, roots and shrubs. Key to this practice is the existence of living stumps, tree roots and seed that, if encouraged, will regrow. The land is protected from being completely cleared or further grazed and this allows trees to grow without disturbance. Once the stumps and trees start to grow, pruning and trimming of trees is required to allow space between trees and promote healthy long tree trunks. Once the trees have matured, intercropping can take place or livestock can be re-introduced to graze.

While requiring some investment in terms of effort, FMNR has climate smart advantages such as controlling rainfall/irrigation run-off, supporting water quality improvements, providing sources of timber or fodder, supporting habitant regeneration for pollinator insect species, acting as sun shade, and reducing soil erosion.

Technical Application

To effectively implement Farmer Managed Natural Regeneration:

  • Step 1: Degraded land needs to be identified and living stumps, roots and seeds need to be encouraged to regrow. This may include periodic watering. Focus should be on indigenous species, and present tree species (existing stumps).
  • Step 2: Consider leaving the field un-grazed to promote tree growth.
  • Step 3: Select tree stumps and the tallest and straightest stems to grow into trees.
  • Step 4: Prune and manage by removing stems and unwanted side branches.
  • Step 5: Maintain the process by occasionally pruning side branches.
  • Step 6: Manage the land consistently to avoid overgrazing, which can lead to further degradation.
  • Step 7: Consider rotational grazing to allow seeds, stumps and underground shrubs to re-grow. This will reduce the cost of replanting. Shrubs and growing trees and saplings need to be protected before introducing livestock. Shrubs and growing trees and saplings need to be protected before introducing livestock.
Return on Investment Realisation Period
Crop Production
Fodder Production
Farm Income
Household Workload
Food Security
Soil Quality/Cover
Biological Diversity
Flooding
Crop/Livestock Water Availability
Wind Protection
Erosion Control
Increase Production
Increase availability of biomass, which improves soil fertility and thus production. The trees/shrubs can be a source of income and reduce costs.
Increase Resilience
Reduces erosion of soil and evaporation. Increases water retention and infiltration. Diversifies income sources. Improves yield stability.
Mitigate Greenhouse Gas Emissions
Locks more carbon in plants and in soil.
PDF File
/sites/secondsite/files/tb/CCARDESATechnicalBrief_35_FarmerManagedNaturalRegeneration_2019-10-17_0.pdf
Benefits and Drawbacks

Benefits

  • FMNR improves soil quality and reduces soil erosion.
  • Improved dry-season pasture.
  • Agricultural management practices such as pruning, and trimming are carried out appropriately in turn improving growth and air circulation.
  • Higher livestock productivity.
  • Provides protection from wind and shade for livestock, when introduced.
  • Increased availability of firewood, thatch and other non-timber forest-products/materials.

Drawbacks

  • The land needs to be managed consistently to avoid overgrazing.

Agroforestry: Silvo-Pasture

Climatic Zone
Decision Making
Farming Characteristics
Mechanisation
Labour Intensity
Initial Investment
Maintenance Costs
Access to Finance/Credit
Extension Support Required
Access to Inputs
Access to Markets
Gender/Youth Smart
Description

Agroforestry is a land management practice that combines the planting and management of trees and shrubs with crops and pasture, providing benefits of soil health, crop yields, resilience to climate change, biodiversity and economic opportunities. Agroforestry encompasses numerous practices, including silvo-pasture, agro-silvo cultural, and agro-silvo-pastural. One such successful agroforestry practice is silvo-pasture – the planting of trees and shrubs within livestock grazing pasture lands. Not to be confused with agrosilvopasture (combination of crops, shrubs/trees and livestock, silvopasture is the combination of trees and shrubs with pastural grazing land. The trees can be regularly or irregularly placed, and in addition to improving soil conditions in pasture lands, also provide production of protein-rich tree fodder for on farm feeding and for cut-and-carry fodder production. If growing larger species of tree, coppicing can also produce timber for building materials and firewood.

Technical Application

To effectively implement hedge planting:

  • Step 1: Purchase saplings of selected tree species from a local nursery or grow saplings in separate on-farm nursery. If growing on-farm, saplings should be held-up with an upright support bamboo/wooden pole. Ideally, the farmer should begin exploring silvopasture tree species beginning with indigenous trees, such as acacias, and other local trees. It is worth considering a mixture of species, as well as mixed shallower and deeper rooted trees.
  • Step 2: Once at a meter or over in height, transplant to pastures, surrounding each individual sapling with a wire mesh cage-tube or insert into five-centimetre diameter PVC pipe to protect from browsers. Plant at least ten to twenty meters apart, in either a random or uniform pattern. This is a matter of preference.
  • Step 3: Once saplings are planted, only allow grazing livestock (cows, sheep, ducks, geese, chickens) in the silvopasture, avoiding browsers (goats, etc), which will strip, damage or destroy the saplings.
  • Step 4: Once mature and above browsing height, two plus meters, remove protective cage or pipe.
  • Step 5: Depending on species, pruning, coppicing etc should be performed every two months to ensure that trees remain healthy and productive, while maximising outputs for in-field and cut and carry fodder.
Return on Investment Realisation Period
Crop Production
Fodder Production
Farm Income
Household Workload
Food Security
Soil Quality/Cover
Biological Diversity
Flooding
Crop/Livestock Water Availability
Wind Protection
Erosion Control
Increase Production
Diversified agricultural outputs supports sustainable agricultural productivity, providing multiple streams of revenue, reducing labour and cost for land clearance and maintaining healthy pasture land.
Increase Resilience
As climate change alters local grazing land, silvopasture can reduce overgrazing and land degradation. Trees introduced into pasture can create a more positive environment for livestock, including shade in warmer climates, and shelter during rainfall.
Mitigate Greenhouse Gas Emissions
Retaining trees within pasture land and minimising complete conversion of land reduces greenhouse gas emissions and retains carbon in the soil.
Additional Information
  • Balehegn, M., 2017. Silvopasture Using Indigenous Fodder Trees and Shrubs: The Underexploited Synergy Between Climate Change Adaptation and Mitigation in the Livestock Sector. Chapter from book The Need for Transformation: Local Perception of Climate Change, Vulnerability and Adaptation Versus ‘Humanitarian’ Response in Afar Region, Ethiopia (pp.493-510). ResearchGate.
  • Jose, S. & Dollinger, 2019. Silvopasture: a sustainable livestock production system. Chapter in J. Agroforest Syst (2019)
PDF File
/sites/secondsite/files/tb/CCARDESATechnicalBrief_34_SilvoPasture_2019-10-17_0.pdf
Benefits and Drawbacks

Benefits

  • Presence of trees can be beneficial to livestock in terms of shade and shelter, as well as enhancing carbon storage and enriching biodiversity.
  • Manure from livestock can improve soil health in grazing land.
  • Leaf litter and pruned material also add organic matter to soil, improving productivity and drainage.
  • Presence of trees can contribute to reducing soil erosion.
  • Trees can produce numerous forest products, including timber for firewood and construction.
  • There is an opportunity to diversify income for small-holder farms and increase food security.
  • Tree trimmings and leaf litter can also be used for in-field or cut and carry fodder.

Drawbacks

  • Requires some investment in terms of purchase of seed and/or saplings.
  • May require adjustment for mixed grazing and browsing livestock patterns.
  • If dietary requirements of livestock are not complete, animals may strip bark from trees. This can be avoided by ensuring that pasture stocking is not too high, and best efforts are made to encourage pasture health and supplementing livestock feed with the necessary minerals, energy and protein.

Boundary Planting

Climatic Zone
Decision Making
Farming Characteristics
Mechanisation
Labour Intensity
Initial Investment
Maintenance Costs
Access to Finance/Credit
Extension Support Required
Access to Inputs
Access to Markets
Gender/Youth Smart
Description

Boundary planting, also known as live fence planting, is a technique used to protect crops from the interference of people and animals that can disturb plant growth. Trees/shrubs are a good example of this approach as they can form a shield when planted along the boundaries of the garden or surrounding a planted field. The trees/shrubs act as wind break to shield plants against strong winds causing physical damage to plants themselves, or the removal of soil (erosion). Additional benefits include the use of branches for firewood or building materials, and the other parts of trees can be used as fodder, fruit or leave harvested for consumption, or for medicinal use. Tree/shrub spacing is critical, as trees that have dense canopies can conversely cause destructive down-drafts, negating the intended benefits. Boundary planting helps limit global warming by mitigating GHG emissions through reducing harmful gases such as, carbon dioxide, from the atmosphere and releasing oxygen.

Technical Application

To effectively implement Boundary Planting practices:

  • Step 1: Plant long lines of two fast growing trees, Caesalpinia velutina trees, between a Bombacopsis quinate and a Swietenia humilis to be replaced over time.
  • Step 2: Consider planting the boundary trees 1.5 metres apart along pre-existing fences.
  • Step 3: Attach metal fencing to the trees to support the large trees without endangering their growth. Harvest fodder when the tree is overgrown.
  • Step 4: Prune lower brunches to encourage upward growth of trees and reduce shed on the plants.
Return on Investment Realisation Period
Crop Production
Fodder Production
Farm Income
Household Workload
Food Security
Soil Quality/Cover
Biological Diversity
Flooding
Crop/Livestock Water Availability
Wind Protection
Erosion Control
Increase Production
Increases availability of tree shrub products (nuts, fruits, timber etc.) and biomass, which improves soil fertility, and thus production.
Increase Resilience
Reduces erosion of soil and evaporation. Increases water retention and infiltration. Diversifies income sources. Improves yield stability.
Mitigate Greenhouse Gas Emissions
Locks more carbon in plants and in the soil.
Additional Information
PDF File
/sites/secondsite/files/tb/CCARDESATechnicalBrief_33_BoundaryPlanting_2019-10-17_0.pdf
Benefits and Drawbacks

Benefits

  • Live fence planting is cost effective, conserves soil moisture, acts a windbreak and reduces soil erosion. These trees have various benefits such as medicinal use, mulch, livestock feeds, fruits, bee forage, timber and firewood.
  • Maintenance of boundary trees is low with short, medium and long ecological and economic benefits.

Drawbacks

  • Boundary planting occupies more land than a single row.

System of Rice Intensification (SRI)

Value Chain
Annual Average Rainfall
Soils
Climatic Zone
Water Source
Altitudinal Zone
Decision Making
Farming Characteristics
Mechanisation
Labour Intensity
Initial Investment
Maintenance Costs
Access to Finance/Credit
Extension Support Required
Access to Inputs
Access to Markets
Gender/Youth Smart
Description

System of Rice Intensification (SRI) is an agro-ecological practice for increasing the productivity of irrigated rice cultivation by changing the management of water, plants, soil and nutrients. SRI promotes the growth of root systems, increases the abundance and diversity of soil organisms by keeping the soil moist but not flooded, and provides frequent aeration and conditioning of soil with organic matter. This agro-ecological practice stimulates plant growth by transplanting young seedlings, avoiding disturbance to roots and providing crops with wider spacing to encourage greater root and canopy growth. The agricultural methodology is based on well-founded agro-ecological principles which have been successfully adapted to upland rice and have shown increased productivity over current conventional planting practices.

Technical Application

To effectively implement SRI practices:

  • Step 1: Consider separation of high-quality seeds from low-quality seeds through soaking them in plain or salt water and the unviable seeds will float on the surface of the water.
  • Step 2: Plant the seeds on an unflooded, raised bed with adequate drainage and fertile soil.
  • Step 3: After 8-12 days, transplant single young seedlings into a grind pattern with wide spacing between hills (25 cm x 25 cm).
  • Step 4: During crop growth period, control the flooding and research and follow alternate wetting and drying irrigation practices.
  • Step 5: Consider application of compost and mineral fertiliser for nutrient enhancement.
  • Step 6: Use a mechanical weeder for the control of weeds and maximisation of soil aeration.
Return on Investment Realisation Period
Crop Production
Fodder Production
Farm Income
Household Workload
Food Security
Soil Quality/Cover
Biological Diversity
Flooding
Crop/Livestock Water Availability
Wind Protection
Erosion Control
Increase Production
Reduced inputs for greater yield.
Increase Resilience
Predictable yields. Higher production equals increased food security/income and resilience..
Mitigate Greenhouse Gas Emissions
May reduce GHG emissions from irrigation pumps.
Additional Information
PDF File
/sites/secondsite/files/tb/CCARDESATechnicalBrief_32_SRI_2019-10-17_0.pdf
Benefits and Drawbacks

Benefits

  • Increased and diversified crop yield resulting in increased farm income.
  • Improved food security.
  • SRI reduces GHG emissions.
  • Existing water availability patterns to accommodate the irrigation schedule.

Drawbacks

  • SRI is a labour-intensive agricultural practice.
  • Occurrence of methane emissions from rice fields caused by flooding.

Alternate Wetting and Drying

Value Chain
Annual Average Rainfall
Soils
Climatic Zone
Water Source
Altitudinal Zone
Decision Making
Farming Characteristics
Mechanisation
Labour Intensity
Initial Investment
Maintenance Costs
Access to Finance/Credit
Extension Support Required
Access to Inputs
Access to Markets
Gender/Youth Smart
Description

Alternate wetting and drying also called intermittent flooding is a technique developed by the International Rice Research Institute (IRRI) to control water consumption in rice fields (CGIAR 2014). This technology saves water throughout the year in areas of variable rainfall. It is designed as a pick-up water system in cases when water consumption is cut. Water levels are monitored and controlled by the removal of excess water, leaving enough water to sustain crops. Alternate wetting and drying reduces greenhouse gas emissions especially methane, which is emitted from flooded rice fields (FAO 2016). The drying phase helps to sustain and develop plant roots. Moreover, costs on fuel used for irrigation are reduced.

Technical Application

To effectively implement Alternate Wetting and Drying practices:

  • Step 1: Alternate wetting and drying should be considered by the farmer after two weeks of rice transplant.
  • Step 2: The farmer should consider digging half of 30 cm tube into soil to monitor water level.
  • Step 3: When the water level is 15 cm below the soil surface the field should be irrigated again with a depth of 3 to 5 cm before water drains.
  • Step 4: This cycle should be repeated until flowering stage to avoid disturbing reproduction because at this stage the crops are sensitive to water stress.
Return on Investment Realisation Period
Crop Production
Fodder Production
Farm Income
Household Workload
Food Security
Soil Quality/Cover
Biological Diversity
Flooding
Crop/Livestock Water Availability
Wind Protection
Erosion Control
Increase Production
Cost of production reduced through less use of water.
Increase Resilience
Maintain production with reduced inputs. Predictable yields.
Mitigate Greenhouse Gas Emissions
May reduce GHG emissions from irrigation pumps.
Additional Information
PDF File
/sites/secondsite/files/tb/CCARDESATechnicalBrief_31_AlternateWettingandDrying_2019-10-17_0.pdf
Benefits and Drawbacks

Benefits

  • Alternate wetting and drying maintains rice yields in areas with variable rainfall/irrigation water supply.
  • Reduces greenhouse gas emission such as methane.
  • The technology can be carried out in regions prone to heavy rainfall.

Drawbacks

  • Water levels need to be monitored carefully to avoid water stress which might decrease yield.
  • Not recommended in areas with potential salinity stress as reduced water inputs might aggravate salinity levels and cause yield decline.

Rainwater Harvesting

Annual Average Rainfall
Climatic Zone
Decision Making
Farming Characteristics
Mechanisation
Labour Intensity
Initial Investment
Maintenance Costs
Access to Finance/Credit
Extension Support Required
Access to Inputs
Access to Markets
Gender/Youth Smart
Description

Rainwater harvesting is an agricultural technique of collecting and storing rainwater or runoff in tanks or natural reservoirs. This practice is mostly practiced in arid or semi-arid areas with temporal and spatial variability of rainfall mostly lost as surface runoff or evaporation. Runoff is harvested and utilised as a preventative measure for soil erosion, as well as a water management strategy for irrigating crops and for livestock water. This technique enables farmers to capture and store rainwater during times of plenty for use during times of scarcity. Rainwater harvesting is a technology that maximises the use of existing freshwater resources and is a useful technology for water resource planners and managers in both governmental and non-governmental organisations, institutions and communities.

Technical Application

To effectively implement Rainwater Harvesting practices:

  • Step 1: Create a water collection zone connected to a gutter system.
  • Step 2: Install filters to the water collection zone.
  • Step 3: Connect a hose pipe for easy distribution of irrigation water.
  • Step 4: If a farmer intends to use water for human consumption other than flushing toilets, etc, water quality must be frequently tested using reliable and low-cost/low-tech solutions.
  • Step 5: Use of filters can be considered to reduce particulate and other pollutants but should be thoroughly investigated – as a separate subject – by the extension officer and the farmer, otherwise it could lead to illness. It is recommended that farms utilise harvested rainwater for irrigation and other farming activities only.
Return on Investment Realisation Period
Crop Production
Fodder Production
Farm Income
Household Workload
Food Security
Soil Quality/Cover
Biological Diversity
Flooding
Crop/Livestock Water Availability
Wind Protection
Erosion Control
Increase Production
More water available to plants when it is needed.
Increase Resilience
Mitigate dry spells.
Additional Information
PDF File
/sites/secondsite/files/tb/CCARDESATechnicalBrief_30_RainwaterHarvesting_2019-10-17_0.pdf
Benefits and Drawbacks

Benefits

  • Rainwater harvesting acts as a source of water at a point where it is needed, usually stored in a tank.
  • Works as an alternative water source in cases of drought or irrigation system breakdown.
  • Rooftop rainwater catchment construction is simple.
  • Success in rainwater harvesting depends on frequency and amount of rainfall.

Drawbacks

  • Asphalt, tar and wood roofs may contaminate the water making it unsafe for direct human consumption.
  • For potable water collection, lead containing gutters should not be used.
  • Harvested water may be contaminated by animal waste.

Permeable Rock Dams

Value Chain
Annual Average Rainfall
Soils
Climatic Zone
Water Source
Decision Making
Farming Characteristics
Mechanisation
Labour Intensity
Initial Investment
Maintenance Costs
Access to Finance/Credit
Extension Support Required
Access to Inputs
Access to Markets
Gender/Youth Smart
Description

A permeable rock dam is a water harvesting technique where flooding rain water is collected in valley bases or other depressions to irrigate crops later/elsewhere, filling in gullies, controlling water flows, increasing crop production and reducing soil erosion.. Permeable rock dams are long and relatively shallow to reduce erosion while accumulating silt and distributing water. They comprise of long low rock walls with smooth crests so that water can spread to avoid overflow from the dam. However, this technology is site specific; it cannot be practiced in areas where there are no rocks/stones and means of transporting these building materials. The impoundment of silt prior to runoff entering a watercourse can be beneficiary to downstream users and can contribute to improved water quality in the catchment

Technical Application

To effectively implement Permeable Rock Dam practices, the following steps should be carried out:

  • Step 1: Consider constructing a permeable rock dam across relatively wide and shallow valleys.
  • Step 2: Permeable rock dams should consist of long, low rock walls with level crest along full length although farmers should consider central spillways where water course has cracks.
  • Step 3: The dam should be between 50-300m in length and 1m in height within a gully.
  • Step 4: Consider making the dam wall flatter on the downslope side than on the upslope side.
  • Step 5: A foundation of small stones should be set in the trench.
  • Step 6: An apron of large rocks is essential to split the erosive force of the overflow.
  • Step 7: Downstream banks of the water stream should be shielded by stone pitching to prohibit the increase of the gully.
Return on Investment Realisation Period
Crop Production
Fodder Production
Farm Income
Household Workload
Food Security
Soil Quality/Cover
Biological Diversity
Flooding
Crop/Livestock Water Availability
Erosion Control
Increase Production
Supports agricultural productivity as soil structure is retained and provides access to more sustainable water supplies.
Increase Resilience
Supports adaptation strategies in climate changes scenarios with improved access to water for irrigation and reducing soil erosion.
Additional Information
PDF File
/sites/secondsite/files/tb/CCARDESATechnicalBrief_29_PermeableRockDams_2019-10-17_0.pdf
Benefits and Drawbacks

Benefits

  • Permeable rock dams increase crop production.
  • Reduce soil erosion.
  • The system increases groundwater recharge.

Drawbacks

  • The technology is site specific; should be on a site where rocks and stones are present.
  • Need for large quantities of stone.

Water Spreading Bunds

Value Chain
Annual Average Rainfall
Soils
Climatic Zone
Water Source
Decision Making
Farming Characteristics
Mechanisation
Labour Intensity
Initial Investment
Maintenance Costs
Access to Finance/Credit
Extension Support Required
Access to Inputs
Access to Markets
Gender/Youth Smart
Description

Water spreading bunds are barriers used on gradual slopes to slow down surface water and slow filter runoff, increasing the chance of infiltration, capturing runoff sediment, and decreasing soil erosion. Bunds can be built of different materials including packed earth or stones. Bunds can be spread across fields or used in micro-settings around individual trees or plants and should be applied in semi-arid or arid conditions. Bunds efficiently spread rainwater across the system and prevent streams from developing. Implementing bunds in areas with adequate rainfall or irrigation, may cause waterlogging and adversely affect crop growth.

Different types of bunds include:

  • Contour bunds: ridges of soil that follow slope contours and can be implemented at a large scale. Crops are cultivated between bunds.
  • Semi-circle bunds: ridges of varying size build in a half-moon or semi-circle. They are generally applied to rehabilitate rangelands and/or in the production of fodder.
  • Contour stone bunds: lines of stones laid in a shallow dug out areas that slow down the flow of runoff
Technical Application

To effectively Water Spreading Bunds the following should be carried out:

  • Step 1: Farmers should consider making earth bunds by hand, animal ploughs or mechanised ploughs.
  • Step 2: Contour bunds:
    • Contour lines must be plotted and marked prior to developing the bund.
    • A 40 cm deep infiltration pit is dug directly above where the bund will be plotted.
    • Bunds should be spread 5 m to 10 m apart.
    • Material from the infiltration pit will be piled and compacted to form a 25 cm to 30 cm in height with a base of 75 cm.
    • Soil is piled to form a ridge along the contour. The more significant the slope, the closer the bunds must be plotted.
  • Step 3: Semi-circle bunds:
    • Contour lines must be plotted and marked prior to developing the bund.
    • A centre point is chosen as diameter for the bund is selected (this could be 3 m or 30 m depending on the available space). From the centre point a string is used to stake out an even semi-circle.
    • Excavate a small trench before the bund and pile the excavated material. Pile and compact a bund wall, wetting it often to form the wall.
  • Step 4: Contour stone bunds:
    • Developed on less steep slopes.
    • Must have access to local stones.
    • Dig out a shallow ditch, 10 cm to 15 cm in depth.
    • Lay largest stones at the bottom of the ditch and pile smaller stone upward.
    • Step 5: Regular monitoring of bunds should take place, especially after rain events or after significant periods of time. Repairs should be done if any damage is found.
Return on Investment Realisation Period
Crop Production
Fodder Production
Farm Income
Household Workload
Food Security
Soil Quality/Cover
Biological Diversity
Flooding
Crop/Livestock Water Availability
Wind Protection
Erosion Control
Increase Production
Reduces soil erosion and enables farmers to maintain agricultural productivity.
Increase Resilience
Reduces soil erosion in higher rainfall environments, especially relevant as climates change.
Additional Information
  • The Food and Agriculture Organisation (FAO), 1991. Water Harvesting. Rome, Italy.
PDF File
/sites/secondsite/files/tb/CCARDESATechnicalBrief_28_waterSpreading_2019-10-17_0.pdf
Benefits and Drawbacks

Benefits

  • Water spreading bunds are implemented on slopes of varying degrees to slow the flow of surface water, increasing infiltration and nutrient capture.
  • Bunds capture water and spread it across an area more evenly, preventing streams, erosion channels and gullies from forming at depression points.

Drawbacks

  • Developing bunds can be laborious.
  • Bunds in areas with adequate rainfall or irrigation may cause waterlogging and affect crop growth.
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Funding Partners

4.61M

Beneficiaries Reached

97000

Farmers Trained

3720

Number of Value Chain Actors Accessing CSA

41300

Lead Farmers Supported