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Promoting Conservation Agriculture in the context of the CCAFS Research
Program in West Africa
Dr Robert ZougmoréCCAFS Regional Program Leader West Africa
Development of Conservation Agriculture based cropping systems for sustainable soil management in West Africa, 05 Feb 2014, Ouagadougou
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1. Major constraints in West Africa2. Key challenges3. CA: a proven climate-smart
agriculture option4. Way forwards
Outline
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WEST AFRICA REGION
Rain-fed agriculture
Chronic Food insecurity
70% rural populations – natural resources
Poverty
Desertification
High climate variability (droughts, flooding)
Population and income
1. A significant increase in the population of all countries except Cape Verde – pessimistic: population of all countries will more than double except Cape Verde
2. Income per capita in the optimistic scenario could range from US$ 1,594 for Liberia to US$ 6,265 for Cote d’Ivoire.
3. Income per capita does not improve significantly in the pessimistic scenario.
Rainfall
Change in average annual precipitation, 2000–2050, CSIRO, A1B (mm) MIROC, A1B (mm)
Despite variations among models, there is a clear indication of: 1.changes in precipitation with either a reduction in the heavy-rainfall areas, particularly along the coast, 2.or an increase in areas of the Sahel hitherto devoid of much rain.3.Southern parts of Ghana, Togo, Benin and Nigeria will be dryer
Changes in yields (percent), 2010–2050, from the DSSAT crop model: CSIRO A1B MIROC A1B
Maize
Sorghum
Groundnut
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Greater demand for food due to population & income growth
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To 2090, taking 18 climate models
Four degree rise
Thornton et al. (2010) Proc. National Academy Science
>20% loss5-20% lossNo change5-20% gain>20% gain
Length of growing period (%)
Length of growing season is likely to decline..
11Vermeulen et al. 2012 Annual Review of Environment and Resources (2012)
19-29% global GHGs from food systems
Environmental footprint
How can smallholder farmers achieve food security under a
changing climate?
Agriculture must become “climate-smart”
• contributes to climate change adaptation by sustainably increasing productivity & resilience
• mitigates climate change by reducing greenhouse gases where possible
• and enhances the achievement of national food security and development goals
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Farm and community:climate-smartpractices, institutions
Global: climate models, international agreements, finance
Climate-smart agriculture happens at multiple levels
National and regional:enabling policies, extension, support, research, finance
• Approach where CCAFS in partnership with rural communities and other stakeholders (NARES, NGOs, local authorities…), tests & validates in an integrated manner, several agricultural interventions
• Aims to boost farmers’ ability to adapt to climate change, manage risks and build resilience.
• At the same time, the hope is to improve livelihoods and incomes and, where possible, reduce greenhouse gas emissions to ensure solutions are sustainable
“Climate-smart villages”
Conservation agriculture is an effective Climate-Smart Agriculture option• CA: farming practices that contribute to
the three key principles of: reducing soil disturbance, maintaining soil cover and practicing crop rotation
• We adopt a broader view of CA (than its current definition): concept for natural resource-saving that strives to achieve acceptable profits with high and sustained production levels while concurrently conserving the environment (FAO, 2009).
• CAWT, where a woody perennial is used as a technological element within the practice (Bayala et al., 2013)
Slide from J. Bayala
CA potential: Soil C sequestration seen as #1 priority (IPCC 2007), has vast potential for climate change mitigation
Mitigation options Mt CO2-eq. yr-1
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CCAFS CA work
• Measuring C sequestration from CA and assessing as a low-emissions agriculture option (Ghana, Burkina, Benin, Senegal, Mali)
• Meta-analysis of crop responses to Conservation Agriculture (Ghana, West Africa)
• SAMPLES Program for GHG quantification, • CA for adaptation and risk management in
maize-legume systems (SIMLESA)• Identifying incentives for adoption of CA
(Indo- Gangetic Plains, East Africa)
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Parklands• Parklands of preserved trees from natural
vegetation: F. albida, V. paradoxa, P. biglobosa…; • Some species are regularly pruned for fodder
healthier livestock;• FMNR consists in selecting & thinning stems which
sprout from indigenous tree and shrub stumps; • Adoption rate may be as high as 63% like in Maradi
region where tree density varies from 60 to 374 individuals ha-1 (Adam et al., 2006);
• Plantation on communal lands: A. macrostachya, A. nilotica, B. rufescens, E. camaldulensis, F. albida, L. leucocephala, M. indica, P. aculeata, P. biglobosa, P. juliflora, Z. mauritiana;
• Plantations on individual lands: A. occidentale, A. indica, Citrus spp., M. indica, P. guayava, P. africana, etc.
Slide from J. Bayala
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Coppicing trees• Trees/shrubs leguminous species planted
at high density as fallows or in associations with crops for biomass production to be used for soil fertility replenishment. Trees are regularly cut to ground level and allowed to re-grow.
• Woody species: Acacia senegal, Sclerocarya birrea and Acacia raddiana, Acacia seyal, A. raddiana, Pterocarpus erinaceus, Prosopis africana, Parkia biglobosa, Acacia auriculiformis, Acacia mangium, Albizzia lebbeck, Gliricidia sepium, Leucaena leucocephala;
• Sometimes associated with annual legumes: Stylosanthes hamata or Mucuna spp.
Slide from J. Bayala
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Green manure• Green manure is the biomass from
herbaceous cover crops grown to be turned under soil as soil amendment and nutrient sources for subsequent crops. Usually the cover crop is established through relay cropping with the staple food crop
• Some tested species: Stylosanthes hamata, Mucuna spp, Crotalaria sp., Tephrosia vogelii, Indigofera astragalima, Tithonia diversifolia; Mucuna spp., Dolichos lablab, Canavalia ensiformis, Cajanus cajan; Calopogonium mucunoides, Lablab purpureus, Macroptilium atropurpureum, etc.;
• Cover crops are used in rotation or in association with crops.
Mucuna spp
Slide from J. Bayala
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MulchingMulching consists of covering the ground with a layer of plant materials in order to conserve soil water, to stimulate the activity of soil biota (e.g. termites) and to reclaim a degraded soil for crop production
• The two most widespread species in farmed fields are G. senegalensis and P. reticultaum (Lufafa et al., 2009);
• This practice exits alone through biomass transfer (northern Burkina) or associated with FMNR (Niger, Mali, Burkina);
• Tested species: Cassia sieberiana, C. lecardi, G. senegalensis, P. reticulatum.
• Protecting soil surface using crop residues reduces water erosion, run off, soil T° and soil evaporation;
• Main constraints are: low availability of the straws and their fraudulent collection and uses for other purposes (feed, building materials, sales, etc.)
Tree/shrub prunings
Crop residues
Slide from J. Bayala
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Rotations/Associations
• Legumes (e.g. cowpea, groundnut) are frequently intercropped or rotated with cereals in the drylands
• Most common association is legumes-cereals (sorghum or millet-cowpea).
• Other types of associations are: peanut-cereals, millet+sorghum+cowpea, Mucuna-cereals, cereals-pigeon pea;
• Rotations vary: cotton-maize-sorghum, peanut-cereals and other legumes-cereals
• Types of fields (homestead, bush fields) and the types of soil (sandy, loamy, clay) or toposequence.
Slide from J. Bayala
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• Technique for recovering encrusted soils that consists in digging pits of 20 to 40 cm in diameter and 10 to 15 cm of depth in order to collect surface waters and to increase infiltration;
• Production increase can go up to 428% in some cases (Reij et al. 2009).
• A basin of half-circle shape with the excavated soil laid out in a semicircular pad;
• Dimensions: 2 to 4 m in diameter, 15 to 25 cm depth and spacing 2 to 4 m;
• Increase in yield of 49 to 112% (Belemviré et al., 2008).
Traditional practices such as zaï, half-moon, stone and earth bunds and grass strips. Increased infiltration, soil moisture retention, SOM content and improving soil structure besides reducing soil erosion.
Soil and Water Conservation practices
Slide from J. Bayala
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Climate-smart villages
Local knowledge & Institutions
Climate information
services
Climate-smart
technologies
Local adaptation
plans
• Learning sites• Multiple partners• Capacity building
Scaling up•Policy•Private sector•Mainstream successes via major initiatives
Scaling up and out
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Outputs/Pathways
Capacity enhancement
Capacity enhancement
Policy impactsPolicy impacts
Informed scientific research
Informed scientific research
OutcomesOutcomes•Enhanced adaptation plansEnhanced adaptation plans•Technology targeted at Technology targeted at climate resilienceclimate resilience•Improved early warning and Improved early warning and social safety netssocial safety nets•Carbon management for Carbon management for improved soilsimproved soils
Policy makersPolicy makers
Policy makersMet agencies
Input suppliers
PartnersPolicy makers
Village leaders
Farmers
Activities
Models and Models and datadata
Policy analysis/ Policy analysis/ engagement engagement
and and communicationcommunication
Participatory Participatory research and research and
capacity capacity buildingbuilding
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WEST AFRICA SAHEL
Water harvesting boosts yields in the
Sahel
oSahel – Droughts common and farming difficult with sparse rainfall.
oChanges in land management – stone bunds and zai pits.
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WEST AFRICA SAHEL Success at scale
oContour bunds established on 200,000 to 300,000 ha.
oYields double those on unimproved land.
oTree cover and diversity increased.
oGroundwater levels rising.
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WEST AFRICA SAHEL
Benefits for food production, adaptation
and mitigationoFood production:
predicted that the improved land will produce enough to feed 500,000 to 750,000 people.increased diversity of food, health benefits.
oAdaptation:contour bunds able to cope with changing weather.
oMitigation: land management prevents further worsening of soil quality.
How do we scale up CA to Landscapes?
•What works?
•Where does it work?
•When does it work?
•Why does it work?
•Who does it work for?
•How does it work?
Determinants of adoption of CA: Adoption (A) is conditioned by its technical performance (P), subject to the opportunities and tradeoffs (T) that operate at farm and village scales and constrained by different aspects of the context (C) in which the farming system operates including market, socio-economic, institutional and policy conditions
The broad framework:
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CSA research & development in West Africa: way forwards
Low adoption rate of CA in West Africa•Cost-effectiveness of CA options•Enabling environment of existing technologies•Participatory testing of CA options•Tools for defining the potential of CA options in various regions•Incentives needed to promote CA and bring it at scale (institutional arrangements and policy measures) •Bring policy and science together to support farmer-led innovations and options in order to achieve outcomes and impacts at national level
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Thank you!www.ccafs.cgiar.org