Cashew living fence on a ditch next to an irrigation channel (Stefan Graf)
Cashew living fences (Cambodia)ដំណំ◌ាចនីដំ◌ា របងរស់ (Khmer)
DESCRIPTION
Living fences of cashew, reinforced with bamboo and/or barbed wire, are used to keepLiving fences of cashew, reinforced with bamboo and/or barbed wire, are used to keepthe cattle off the garden or the rice seedbed.the cattle off the garden or the rice seedbed.Cashews (Anacardium occidentale) are fast growing, waterlogging tolerant tropical treesthat can be used as living fences. The cashews act as fence posts, and are reinforced withbamboo poles and/or barbed wire. The living fences are used to either fence cattle intofields or fence them off, usually around the house. The fenced areas can be plantedduring the dry season. Without fences, the cattle are free roaming and use to destroy thecrops.Besides fencing the cattle, the purposes of cashew living fences are the production ofnuts and fruits, fuel, and soil enhancer. The nuts are sold, but there is no market for thefruits, thus they are fed to cattle or let to rot. The wood is used to cook or to producecharcoal; the ash is added to the compost. The leaves are gathered as well and added tothe compost.Although cashews can stand waterlogged conditions, they prefer a well-drained soil.Thus a small berm is built up on the emplacement of the fence, and sown with cashewseeds spaced from 0.5 to 3 m. Cashews grow faster when directly sown than whentransplanted. The spacing varies according to the farmers’ purpose. If a higherproduction of nuts is intended, the spacing is wider; if the fence is more important, theplants are grown closer. Cattle do not eat the leaves and branches, thus do not needprotection from grazing. One year after sowing the cashews, the trees are tall enough toact as fence posts and support bamboo pole as well as barbed wire. The bamboo iseither gathered from the wild or grown in the fields and home gardens. The bamboo isfixed to the living posts with natural fibers/vines or old clothes, and has to be replacedevery two to three years to withstand cattle.The analysed area is flat (slope < 2%), with a tropical climate (dry season from Novemberto May and wet season from June to October), and the soils are mostly sandy or loamy.The soil has a low fertility, contains little organic matter, and acidifies. The area has beendeforested a long time ago, and the groundwater table is rather high (1-2 m during thedry season, on the surface during wet season). Due to climate change, farmers notice more erratic rainfalls, temperature rises andmore recurrent droughts. Rice is the predominant crop grown in the area, since it servesas staple food (mix subsistence and commercial activities). Cattle are usually grazing onthe fields after the harvest, without much control. Thus the cattle grazes too often andtoo much on the same spot, leading to degradation.The increasing migration rate (the young generation leaves the villages to work in thecities, garment industry or abroad) results in a decrease of available labour force in thearea which has detrimental effects on the agricultural activities. Furthermore, the civilwar in the 1970s (Khmer Rouge) led to the loss of agricultural knowledge. Several NGOsare trying to re-establish the knowledge.
LOCATION
Location:Location: Krang Liav, Rolea Pha-er,Kampong Chhnang, Cambodia
No. of Technology sites analysed:No. of Technology sites analysed:
Geo-reference of selected sitesGeo-reference of selected sites104.55439, 12.22968
Spread of the Technology:Spread of the Technology: evenly spreadover an area (approx. < 0.1 km2 (10 ha))
Date of implementation:Date of implementation: 10-50 years ago
Type of introductionType of introductionthrough land users' innovation✓as part of a traditional system (> 50years)during experiments/ researchthrough projects/ externalinterventions
Wocat SLM Technologies Cashew living fences 1/6
Cashew living fence on a ditch next to an irrigation channel(Stefan Graf)
Close view on a cashew living fence, with bamboo poles andbarbed wire. (Stefan Graf)
CLASSIFICATION OF THE TECHNOLOGY
Main purposeMain purposeimprove productionreduce, prevent, restore land degradationconserve ecosystem✓protect a watershed/ downstream areas – in combination withother Technologiespreserve/ improve biodiversityreduce risk of disastersadapt to climate change/ extremes and its impactsmitigate climate change and its impactscreate beneficial economic impactcreate beneficial social impact
Land useLand useMixed (crops/ grazing/ trees), incl. agroforestryMixed (crops/ grazing/ trees), incl. agroforestry - Silvo-pastoralism
Water supplyWater supply
Number of growing seasons per year:Number of growing seasons per year: 1Land use before implementation of the Technology:Land use before implementation of the Technology: n.a.Livestock density:Livestock density: 25-50 LU /km2
rainfedmixed rainfed-irrigated✓full irrigation
Purpose related to land degradationPurpose related to land degradationprevent land degradationreduce land degradation✓restore/ rehabilitate severely degraded land✓adapt to land degradationnot applicable
Degradation addressedDegradation addressedsoil erosion by windsoil erosion by wind - Et: loss of topsoil
chemical soil deteriorationchemical soil deterioration - Cn: fertility decline andreduced organic matter content (not caused by erosion)
biological degradationbiological degradation - Bc: reduction of vegetationcover, Bl: loss of soil life
SLM groupSLM groupintegrated crop-livestock management
SLM measuresSLM measuresvegetative measuresvegetative measures - V1: Tree and shrub cover
TECHNICAL DRAWING
Technical specificationsTechnical specifications
Wocat SLM Technologies Cashew living fences 2/6
Author: Stefan Graf, Switzerland
On a dike cashews (Anacardium occidentale) wereplanted a few years back. After they grew up, thefence was done with barbed wire and bamboopoles.Kampong ChhnangDate: 2014
Technical knowledge required for field staff /advisors: lowTechnical knowledge required for land users: lowMain technical functions: increase of biomass(quantity), spatial arrangement and diversificationof land useSecondary technical functions: increase in organicmatter, increase in nutrient availability (supply,recycling,…), improvement of water quality,buffering / filtering water, reduction in wind speed
Aligned: -along boundaryVegetative material: T : trees / shrubs, F : fruit trees/ shrubsVertical interval within rows / strips / blocks (m):0.5-3mFruit trees / shrubs species: Cashew, seeded.
ESTABLISHMENT AND MAINTENANCE: ACTIVITIES, INPUTS AND COSTS
Calculation of inputs and costsCalculation of inputs and costsCosts are calculated:Currency used for cost calculation: n.a.n.a.Exchange rate (to USD): 1 USD = n.aAverage wage cost of hired labour per day: 5.00
Most important factors affecting the costsMost important factors affecting the costsThe costs are most determined by the availability of bamboo. Ifit is not grown in the garden, it has to be gathered in the forestthat is related to time consuming transportation. Or barbedwire has to be purchased. Note: The time used to gather theleaves for the compost or to cut the branches to makecharcoal/ash as soil amendment was not included in therecurrent activities as these activities are neither related to themain purpose of living fences nor done by all the farmersapplying this technology.
Establishment activitiesEstablishment activities1. Building small bound to sow the cashews. (Timing/ frequency: Dry season, before sowing)2. Sowing cashews on the bounds (Timing/ frequency: Beginning of rainy season)3. Gathering bamboo in the forest, building the fence (Timing/ frequency: None)
Establishment inputs and costsEstablishment inputs and costs
Specify inputSpecify input UnitUnit QuantityQuantityCosts perCosts perUnit (n.a.)Unit (n.a.)
Total costsTotal costsper inputper input
(n.a.)(n.a.)
% of costs% of costsborne byborne by
land usersland usersLabourLabourlabour 1.0 17.5 17.5 100.0EquipmentEquipmenttools 1.0 12.0 12.0 100.0barbed wire 1.0 21.0 21.0 100.0Plant materialPlant materialseeds 1.0 1.0 1.0 100.0Total costs for establishment of the TechnologyTotal costs for establishment of the Technology 51.551.5
Maintenance activitiesMaintenance activities1. Gathering bamboo in the forest, building the fence (Timing/ frequency: Every 2-3 years)
Maintenance inputs and costsMaintenance inputs and costs
Specify inputSpecify input UnitUnit QuantityQuantityCosts perCosts perUnit (n.a.)Unit (n.a.)
Total costsTotal costsper inputper input
(n.a.)(n.a.)
% of costs% of costsborne byborne by
land usersland usersLabourLabourlabour 1.0 3.0 3.0 100.0Total costs for maintenance of the TechnologyTotal costs for maintenance of the Technology 3.03.0
NATURAL ENVIRONMENT
Average annual rainfallAverage annual rainfall< 250 mm251-500 mm501-750 mm751-1,000 mm1,001-1,500 mm✓1,501-2,000 mm
Agro-climatic zoneAgro-climatic zonehumidsub-humid✓semi-aridarid
Specifications on climateSpecifications on climate1486.45 mm 2013 in Kampong Chhnang Thermal climate class: tropics. 27-35°C
Wocat SLM Technologies Cashew living fences 3/6
2,001-3,000 mm3,001-4,000 mm> 4,000 mm
SlopeSlopeflat (0-2%)✓gentle (3-5%)moderate (6-10%)rolling (11-15%)hilly (16-30%)steep (31-60%)very steep (>60%)
LandformsLandformsplateau/plains✓ridgesmountain slopeshill slopesfootslopesvalley floors
AltitudeAltitude0-100 m a.s.l.✓101-500 m a.s.l.501-1,000 m a.s.l.1,001-1,500 m a.s.l.1,501-2,000 m a.s.l.2,001-2,500 m a.s.l.2,501-3,000 m a.s.l.3,001-4,000 m a.s.l.> 4,000 m a.s.l.
Technology is applied inTechnology is applied inconvex situationsconcave situationsnot relevant
Soil depthSoil depthvery shallow (0-20 cm)shallow (21-50 cm)✓moderately deep (51-80 cm)deep (81-120 cm)very deep (> 120 cm)
Soil texture (topsoil)Soil texture (topsoil)coarse/ light (sandy)✓medium (loamy, silty)✓fine/ heavy (clay)
Soil texture (> 20 cm belowSoil texture (> 20 cm belowsurface)surface)
coarse/ light (sandy)medium (loamy, silty)fine/ heavy (clay)
Topsoil organic matter contentTopsoil organic matter contenthigh (>3%)medium (1-3%)✓low (<1%)✓
Groundwater tableGroundwater tableon surface✓< 5 m5-50 m> 50 m
Availability of surface waterAvailability of surface waterexcessgood✓mediumpoor/ none
Water quality (untreated)Water quality (untreated)good drinking waterpoor drinking water(treatment required)
✓for agricultural use only(irrigation)unusable
Is salinity a problem?Is salinity a problem?
Occurrence of floodingOccurrence of flooding
YesNo
YesNo
Species diversitySpecies diversityhighmedium✓low
Habitat diversityHabitat diversityhighmedium✓low
CHARACTERISTICS OF LAND USERS APPLYING THE TECHNOLOGY
Market orientationMarket orientationsubsistence (self-supply)mixed (subsistence/commercial
✓commercial/ market
Off-farm incomeOff-farm incomeless than 10% of all income10-50% of all income✓> 50% of all income
Relative level of wealthRelative level of wealthvery poorpooraverage✓richvery rich
Level of mechanizationLevel of mechanizationmanual work✓animal traction✓mechanized/ motorized
Sedentary or nomadicSedentary or nomadicSedentarySemi-nomadicNomadic
Individuals or groupsIndividuals or groupsindividual/ household✓groups/ communitycooperativeemployee (company,government)
GenderGenderwomen✓men✓
AgeAgechildrenyouthmiddle-agedelderly
Area used per householdArea used per household< 0.5 ha0.5-1 ha1-2 ha✓2-5 ha5-15 ha15-50 ha50-100 ha100-500 ha500-1,000 ha1,000-10,000 ha> 10,000 ha
ScaleScalesmall-scalemedium-scale✓large-scale
Land ownershipLand ownershipstatecompanycommunal/ village✓groupindividual, not titled✓individual, titled
Land use rightsLand use rights
Water use rightsWater use rights
open access (unorganized)communal (organized)✓leasedindividual✓open access (unorganized)✓communal (organized)leasedindividual
Access to services and infrastructureAccess to services and infrastructurehealth poor ✓ good
education poor ✓ good
technical assistance poor ✓ good
employment (e.g. off-farm) poor ✓ good
markets poor ✓ good
energy poor ✓ good
roads and transport poor ✓ good
drinking water and sanitation poor ✓ good
financial services poor ✓ good
IMPACTS
Socio-economic impactsSocio-economic impactsCrop production decreased ✓ increased
Wocat SLM Technologies Cashew living fences 4/6
Due to shading and root competition.wood production decreased ✓ increased
Used as fuel and charcoal.energy generation (e.g. hydro,bio)
decreased ✓ increased
Firewood production.demand for irrigation water increased ✓ decreased
Quality, trough bioremediation of groundwater.Difficult to quantify.
diversity of income sources decreased ✓ increased
If spaced, production of cashew nuts and apples.
Socio-cultural impactsSocio-cultural impactsfood security/ self-sufficiency reduced ✓ improved
Improved self-sufficiency on firewood.contribution to human well-being
decreased ✓ increased
Every additional income source/diversificationincreases the human well-being.
Ecological impactsEcological impactsevaporation increased ✓ decreased
But increased evapotranspiration.nutrient cycling/ recharge decreased ✓ increased
Nutrients are picked up from the groundwater, andput back into the cycle.
soil organic matter/ belowground C
decreased ✓ increased
Leaves used for compost.biomass/ above ground C decreased ✓ increased
beneficial species (predators,earthworms, pollinators)
decreased ✓ increased
Wormcasts could be seen under the trees. Difficult toquantify.
habitat diversity decreased ✓ increased
Tree layer.wind velocity increased ✓ decreased
Off-site impactsOff-site impactsgroundwater/ river pollution increased ✓ reduced
Bioremediation difficult to quantify.wind transported sediments increased ✓ reduced
Slowing down of wind speed.
COST-BENEFIT ANALYSIS
Benefits compared with establishment costsBenefits compared with establishment costsShort-term returns very negative ✓ very positive
Long-term returns very negative ✓ very positive
Benefits compared with maintenance costsBenefits compared with maintenance costsShort-term returns very negative ✓ very positive
Long-term returns very negative ✓ very positive
CLIMATE CHANGE
Gradual climate changeGradual climate change
Climate-related extremes (disasters)Climate-related extremes (disasters)
Other climate-related consequencesOther climate-related consequences
annual temperature increase not well at all ✓ very well
local rainstorm not well at all ✓ very well
local windstorm not well at all ✓ very well
drought not well at all ✓ very well
general (river) flood not well at all ✓ very well
reduced growing period not well at all ✓ very well
ADOPTION AND ADAPTATION
Percentage of land users in the area who have adopted thePercentage of land users in the area who have adopted theTechnologyTechnology
single cases/ experimental1-10%10-50%more than 50%
Of all those who have adopted the Technology, how many haveOf all those who have adopted the Technology, how many havedone so without receiving material incentives?done so without receiving material incentives?
0-10%10-50%50-90%90-100%
Has the Technology been modified recently to adapt to changingHas the Technology been modified recently to adapt to changingconditions?conditions?
To which changing conditions?To which changing conditions?
YesNo
Wocat SLM Technologies Cashew living fences 5/6
climatic change/ extremeschanging marketslabour availability (e.g. due to migration)
CONCLUSIONS AND LESSONS LEARNT
Strengths: land user's viewStrengths: land user's viewCattle are fenced in or off. The cattle do not enter the homegardens of the neighbours and cannot escape on the ricefields.Branches can be used as firewood or to make charcoal, andthe leaves can be used as compostProduction of fruits and nuts.
Strengths: compiler’s or other key resource person’s viewStrengths: compiler’s or other key resource person’s viewReduced wind speed.Bioremediation of groundwater.Increased soil cover.
Weaknesses/ disadvantages/ risks: land user's viewWeaknesses/ disadvantages/ risks: land user's view how toovercome
Shading of crops nearby. Cut back the cashews since theyare pollarding trees. However, this will drastically reduce thefruit production.Root competition with other trees. Plant next to shallowrooted crops.No more market for cashew apples as there is anoverproduction. Process as wine or dry. Can also be fed tocattle.
Weaknesses/ disadvantages/ risks: compiler’s or other keyWeaknesses/ disadvantages/ risks: compiler’s or other keyresource person’s viewresource person’s view how to overcome
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→REFERENCES
CompilerCompilerStefan Graf ([email protected])
ReviewerReviewerDeborah Niggli ([email protected])
Date of documentationDate of documentation: Oct. 27, 2014 Last updateLast update: Feb. 28, 2017
Resource personsResource personsStefan Graf ([email protected]) - SLM specialistLean Hak Khun ([email protected]) - SLM specialistBin Sreytouch ([email protected] ) - SLM specialistKhonhel Pith ([email protected]) - SLM specialist
Full description in the WOCAT databaseFull description in the WOCAT databasehttps://qcat.wocat.net/en/wocat/technologies/view/technologies_1643/
Linked SLM dataLinked SLM datan.a.
Documentation was faciliated byDocumentation was faciliated byInstitution
Local Agricultural Research and Extension Centre (LAREC) - CambodiaSociety for Community Development in Cambodia (SOFDEC) - Cambodia
Projectn.a.
Wocat SLM Technologies Cashew living fences 6/6