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CONSERVATION AGRICULTURE IN EAST AND SOUTHERN AFRICA MAIN MESSAGES
What is and what is not climate-smart agriculture (CSA)? That existential question sparks debate, complicates implementation and fractures the development community. CSA X-rays provide a detailed analysis of what science and scientists tell us about the ‘climate-smartness’ of proposed CSA interventions. Each section contains an infographic that illustrates the potential impact of the intervention on outcomes when changing practices1. Key messages for the CSA X-ray on Conservation Agriculture in East and Southern Africa are:
1 X-rays were designed to print as either 4-page leaflets that include key messages and hints on interpretation or 2-page briefs.
Productivity
Yield benefits from using conservation agriculture, by comparison to conventional systems, are typically positive in the literature from this region but vary depending both on the cropping system, year and site (ranging from -20 to 200%). Information on the impacts on income is sparse and shows a diversity of possible affects.
Resilience/
Adaptive Capacity
Mitigation
Climate Risks
The Business Case
Scaling up
Barriers to adoption
Most of the data available relates to impacts on the physical resilience of the systems such as changes in soils chemical properties and affects on drought and largely suggests that conservation agriculture improves these system properties. Much less is known about the impact of conservation agriculture on economic and social properties of the system. However, expert opinion and limited data indicates that there may be tradeoffs in terms of labor and gender concerns with conservation agriculture. Conservation agriculture is unlikely to reduce greenhouse gas production or increase soil carbon stocks in East and Southern Africa with any of the many possible variations in implementation. Because of the positive affects on soil physical properties, conservation agriculture has potential to mitigate many of the precipitation and seasonal affects of climate change. In addition, the impact of rising temperatures may be mitigated to some degree due to soil cover. Conservation agriculture performs poorly across indicators of system performance including negative net present value, cost benefit and with delayed returns on investment. There has been relatively limited uptake of conservation in East and Southern Africa, with only 100,000 households or less predicted to be utilizing the practice in Zambia, Malawi or Zimbabwe, for example. The factors affecting adoption of conservation agriculture are inconsistent across studies. Many of factors have both positive and negative impacts depending on the study and few are universally influential in the same direction. Furthermore, most characteristic are only statistically significant in fewer than half of the studies except for ones such as income.
X
RESILIENCE
Bare bones evaluation of climate-smart agriculture practices & technologies
RAY
MITIGATION
COMpONENT pRACTICES
pRODUCTIVITY
CSA TECHNOLOGY
Combinations of minimal soil disturbance, crop rotations and maintaining soil cover
Conservation agriCulture (Ca)
in East & Southern Africa
Percent change in yield or income from the CSA practice relative to a baseline
practice for all crops combined. Dashed lines represent the mean Percent
change, and bar length shows the 95% confidence intervals around the mean.
Heat map showing effects of improved practice on greenhouse gas emissions and removals
land preparation
ploughing (p)
reduced tillage (rt)
Zero tillage (zt)
residue retention (r)
Cover Crops (cc)
Mulch (mul)
rotations (rr)
soil & Water ManageMent
nutrient ManageMent
Manure (man)
inorganic fertilizer (if)
agrobiodiversity
local variety (lv)
improved variety (iv)
trees (t)
The magnitude (size of bubble), sign (position of bubble), and amount of evidence (fill of bubble) for impact of CSA practices on resilience indicators. Color of the buble indicates the type of resilience.
YEILD
MaiZe (Ca)
CoWpea
INCOME
ChiCkpea
teF
groundnut
sorghuM
Wheat
Cotton
MaiZe & beans
MaiZe
MaiZe (rt)
beans
500-50-100 100 150 200 250 300
% changeEmissions intensity
Soil fluxes
Soil Carbon
Reduced tillagert
Zero tillagezt
Crop rotationrot
Residue retentionres
Cover cropcc
Mulchmul
Manureman
Inorganic fertilzerif
Improved varietiesiv
Treest
reduced tillage & crop rotation
ct rot
Biomasscarbon
No change
Increases GHG Emissions
Decreases of of fsets GHG emissions
reduced tillage & mulch
rt mul
reduced tillage & crop rotation & mulchCA
pHYSICAL
ConflictingWorsens Improves
ECONOMIC
SOCIALA lot
Some
None
SIZE OF EFFECT
TYpE OF RESILIENCE
AMT OF EVIDENCE
Water
Drought
female
work hours
ouput control by
women
ouput control by
men
water use effeciency
soil
moisture
field
farm
target
vulnera-
ble
male
work
hours
heat
no. products consumed
nitrogen use effe-ciency
genetic
no. product sales
amt. of product for sale
land-scape
soil carbon
soil nitrogen
erosion
labour
CLIMATE RISKS
BUSINESS CASE
SCALING UpCURRENT ADOpTION
1. High mean temperature2. Days with a max temp > 35ºC3. Days with a max temp > 40ºC
Temperature
4. Lower mean rainfall5. Higher mean rainfall6. Large scale flood
1
2 3
4
5
6
7 8 9 10 11 12 13 14 15 1
6 1
7 1
8
TEMpERATURE
pRECIpITATION
SEASONAL CHANGES7. Flash floods8. High 1-hour rainfall intensity9. Heavy hail events10. Rainfall distribution (variability) within season11. 10-day dry spells12. Seasonal droughts13. Consecutive seasonal droughts14. Later onset of rainfall season15. Earlier end date of the rainfall season16. Decreased predictability of the rainfall season17. Increased uncertainty in rainfall distribution18. Increases in cloudiness and humidity
significant reductionmoderate reductionminimal reduction
ZAMBIA 5-20%
MALAwI
ZIMBABwE
= 10k households
The relative reduction in climate risk by using conservation agriculture. Dots closer to the center indicate greater mitigation of each climate risk, identified by numbers.
(A)Change in economic performance relative to the conventional practice, (B) Semi-quantitative assessment of risk (change of decrease in yields) vs. reward (mean increase in yield) for various crops under CSA practices identified by code (C) Net returns (USD/ha) on investment over time.
BARRIERS TO ADOpTION
FarM & household CharaCteristiC
aMt oF evidenCe
0 100
iMpaCt on adoption
awareness
Attitude toward conservationProgram participation
Concern of erosionAwareness of environmental threats
Perceived health threatConcern for groundwater pollution
information
ExperienceTechnical assistanceSource of informationAccess to information
Management knowledge/skills
site conditions
RainfallSlope
Soil typeTemperature
High productivity soilHighly erodable land
Length of growing season
Market access
Output pricesDistance to paved road
availability of technology
Farm equipmentAvailability of machinery
household demographics
EducationAge
Farm sizeKin as partners
income
IncomeGross farm incom
Farm profitabilityOff-farm income
Importance of crop revenues in income
policy
Tenure
social connectivity
Membership in organizations
-100 0 100
Farm management
Area plantedImportance of livestock
Soil erosion rateFarm/field types
Proportion of ha irrigatedEmphasis on grain farming
Pesticides appliedCropping system/crop rotation
Impact of CA on production costs
Wealth & assets
Family laborHired labor
Debt level/ratio Wealth indicators
Impact on adoption shows the proportion of studies where farm and household characteristics have a positive (to the right) or negative (to the lef t)s impact on adoption, and significance shows the number of studies where that factor was significant (filled bar) or insignificant (open bar) on adoption.
(zt)
-7
(zt)
-5%
(zt)
-5%
(zt+mul)
-13%
(zt+mul)-4%
(zt+mul)
0%
(zt+mul)
-23%
(zt+rot+mul)
-23%
AConventional
practice
-25 %
Cost Benefit
Cost Benefit
net present value (20yr)
net present value (10yr)
net present value (3yr)
net present value (20yr)
net present value (10yr)
net present value (3yr)
Current rates of adoption of Conservation agriculture
BLOW RISK/HIGH REWARD
LOW RISK/LOW REWARD HIGH RISK/LOW REWARD
HIGH RISK/HIGH REWARD
cf
rtrt
rtrt
rt
rt
rt
rtrt
maize
sorghum
cotton
wheat
beans
tef
chickpea
cowpea
groundnut
2006 2007 2008 2009 2010 2011
1,600
1,200
800
400
0
conventional location 1 location 2
C
The CSA X-ray is based on published data and expert opinion. Sources used for each indicator can be found on the ‘CSA X-ray’ repository on Harvard’s Dataverse. We thank the CGIAR Research Program on Climate Change, Agriculture, and Food Security for funding the Partnerships for Scaling Climate-Smart Agriculture (P4S) Project that conceived of the X-rays and the United States Agency for International Development for their support of staff executing the vision.
Christine Lamanna: [email protected] For general inquiries contact Todd Rosenstock: [email protected]
MORE INFORMATION CONTACT
READING THE X-RAY
Description of the CSA technologies covered. Each has an abbreviation that will be used throughout the X-RAY. Percent change (%) in productivity indicators under CSA technologies as compared to conventional practices. The vertical line at 0% represents no change in productivity. In each colored bar, the mean percent change is shown as a dashed line, and the width of the bar represents the 95% confidence interval around the mean for percent change in productivity. The position of the bar indicates the magnitude of change and the size the bar is indicative to the variability for the crop and practice. Change in greenhouse gas emissions and carbon stocks under CSA shown as a heat map. Warm colors (orange to purple) mean an increase in climate forcing or lower mitigation potential, while cool colors (green to blue) mean a decrease in climate forcing or higher mitigation potential. Where there is no expected change or no data, the square is empty. Data based on published literature and expert opinion are shown for soil carbon, aboveground biomass, soil GHG fluxes, and emissions intensity (emissions per unit product). Impact of CSA practices on indicators of physical (blue), economic (green), and social (orange) resilience. The size of the bubble relates to the magnitude of change, for example a larger change in that indicator under CSA. The location of the bubble on the horizontal axis indicates the direction of the change. Bubbles to the right of the dotted line show improvement in resilience, while bubbles to the left decrease that proxy for resilience. Bubbles siting on the dotted line mean that there is conflicting evidence – sometimes that resilience indicator improves and sometimes it doesn’t. The fill (shading) of the bubble indicates how much evidence is available. Open bubbles mean the change is theorized but no evidence is available, shaded bubbles mean some evidence is available, and filled bubbles mean a lot of evidence is available. Around the semi-circle, unique numbers identify eighteen climate risks potentially addressed by CSA. The semi-circle is divided into three levels (boxes) indicating the degree to which the practice may mitigate climate risks (minimal, moderate, or significant) and colors representing various categories of climate risks (temperature, precipitation, and seasonal changes). For each climate risk, a circular mark is placed in the respective position (box) indicating how well that intervention addresses that climate risk. (A) Percent change in economic performance relative to the conventional practice for various indicators. Increases in economic performance are positive bars, whereas decreases in economic performance are negative bars. (B) Risk vs. Reward for CSA practice/crop combinations. Reward relates to the change in yield is on the vertical axis, and risk relating to the chance of decrease in yields is on the horizontal. (C) Illustrative economic performance of CSA practices relative to a control over time. For current adoption, each person icon represents a number of small farmers who have adopted that particular practice in that location. In Barriers to Adoption, each farm and household characteristic (listed in grey) has an associated impact on adoption (left orange panel) and significance (right blue-green panel). Impact on adoption panel shows the proportion of studies where that factor positively (to the right) and negatively (to the left) affected adoption. Interesting to note bars that cross the vertical center line (positive and negative effects depending on context) and the size of the bar indicating how many studies have included that factor. The significance panel shows the number of studies conducted on that factor (open bar) and the number where that factor significantly impacted adoption (filled bar).
PRODUCTIVITY
MITIGATION
RESILIENCE
CLIMATE RISKS
BUSINESS CASE
SCALING UP
TECHNOLOGIES