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Development of 'climate smart'
cropping systems for southern
Africa?
Leonard Rusinamhodzi26 March 2014
1400-1500 HRS (GMT + 1)
Presentation outline
Context / issues in Southern Africa
Highlights research experience
New project
Maize based mixed crop-livestock systems are dominant
• Crop residues are important
for livestock feed
• Manure is important for
crop production
Background - Farming systems of southern Africa
Conflicts of resource use……….
Degraded pastures intensify the conflict for crop residue uses
Other systems/ conditions
Extensification systems also exist….
Slash and burn
Lack of inputs (manure, fertiliser, improved germplasm)
Extension support is very weak
charcoal
Soil fertility status….Predominantly sandy soils (Arenosols)• Pockets of fertile red clays soils• Current crop production systems lead to accelerated loss of soil
fertility
Time of cultivation (years)
0 5 10 15 20
SO
C (
t h
a-1
)
30
40
50
60
70
80
90
Time of cultivation (years)
0 2 4 6 8 10 12 14 160
20
40
60
80
Clay soil Sandy soil
Beyond farmers’ control - poor rainfall distribution
Poor rainfal distribution
Severe mid-season dry spells
(b)
Days after planting
0 50 100 150 200
Cum
ulative rainfall (mm
)
0
200
400
600
800
1000
2007/08 season 2009/10 season 2010/11 Season
(a)
Cropping season
2002/032003/04
2004/052005/06
2006/072007/08
2008/092009/10
20010/11
Total seasonal rainfall (m
m)
0
200
400
600
800
1000Long-term average Average = 730 mm,
CV = 9 %
Presence of different farm types
• Differences in resource ownership, production orientation
• Need specific targeting to specific constraints and opportunities
CA
How do we intensify crop production?
Gra
in le
gum
es
Gre
en
manure
s
Basket of technologies exists but…..• mismatch between farmers’
objectives and technology outputs
• Farmers are interested in technologies that ensure food security and cash income
• Improving soil fertility is seldom mentioned
Agro
fore
stry
Fodder
legum
es
Manure
Fert
ilize
rs
The approach -AfricaNUANCES FrameworkNUtrient Use in Animal and Cropping Systems - Efficiencies and Scales
Used to analyse current livelihoods, explore options for their development and reveal trade-offs
• Mainly relied on field based methods (interviews, transect walks, FGD)
http://www.africanuances.nl/
Outputs and insights• Downloadable from Researchgate
Updated list Google scholar…………..
Literature review – what role for conservation agriculture?
• Continuous maize• Early seasons lead to
smaller yield• Overall, no yield
advantage of CA
• Maize-legume rotation• Yield advantage in the
long-term
NT, continuous maize
Duration of study (years)
0 5 10 15 20 25 30 35 40 45 50
Weighted m
ean diference (t ha-1
)
-6
-4
-2
0
2
4
6n = 364 NT with rotation
Duration of study (years)
0 5 10 15 20 25 30 35 40 45
Weighted m
ean difference (t ha-1
)
-4
-2
0
2
4
6
n = 294
What is needed for CA……………….
• Crop residues need to be retained in situ to reduce labour demands
• need for fencing in combination with alternative feed
• Integration of legume crops
Cotton-cowpea intercropping
• Increases productivity, high LER, increased BNF
• Increases productivity of rotational maize
• Pesticide concerns on cowpea leaves
• Cowpea in the middle of the rows hampers mechanical weeding
Maize pigeonpea intercropping………..
• Within row intercropping• Alternate hills in same row,
3 plants per hill
• Distinct row intercropping• 2 rows of maize alternate with a
row of legume
The beauty of maize-pigeonpea intercropping
Early growth• Pigeonpea does
not compete with maize
Late growth• Maize does not
compete with pigeonpea
Time (minutes)
0 10 20 30 40 50 60 70 80 90 100 110 120
Infiltration rate (mm
hr-1
)
0
10
20
30
40
50
60
70
80
Continuous maize1 year intercropping3 year intercropping5 year intercropping
Duration of intercropping on rainfall infiltration
• Long-term large biomass production in combination with reduced tillage
Pigeonpea vs. communal grazing
• late maturity of pigeonpea delays free-grazing of cattle
• allows farmers to retain crop residues as mulch if they choose to
• use of ‘ratoon’ pigeonpea reduces costs of seed and the need for tillage
Relay intercrop vs. climatic risk
Vunduzi (2009/10 season)
Days after planting
0 20 40 60 80 100 120 140 160
Cum
ulative rainfall (mm
)
0
200
400
600
800
1000
54 Days
• Relay intercropping reduces climatic risk of total crop failure
Pushing the envelope - where to apply cattle manure?
Homefield Outfield
Yield
A
B
C
Midfield
D
E
• Should farmers maintain current status
• Or they should rebuild fertility of the outfields at the expense of homefields
• Manure quantities are often limiting at the farm level
Results – yield recovery potential
• Application of 100 kg N ha-1 maintained yields below 1 t ha-1 in sandy homefields but approached zero in sandy outfields
• Restoration of crop productivity in the degraded sandy soils was only relevant when a combination of mineral fertiliser and manure were used
• Yields on outfields were significantly smaller than on homefields after nine seasons for both soil types.
Trade-off analysis on crop residue use suggested that…
farmers who own cattle have limited scope to allocate crop residues for soil cover as it leads to significant loss in animal productivity and economic value
e.g. retention of all crop residues in the field reduced farm income by US$937 and US$738 per year for RG1 and RG2 farmers respectively
(a) crop versus animal productiviy
Maize grain yield (t farm-1)
3.5 4.0 4.5 5.0 5.5 6.0
Cattle body w
eight (t farm-1
)
3.2
3.4
3.6
3.8
4.0
4.2
20% manure retention40% manure retention60% manure retention
(b) crop yield versus milk produced
Maize grain yield (t farm-1)
3.5 4.0 4.5 5.0 5.5 6.0
MIlk for household (t farm
-1)
1.1
1.2
1.3
1.4
1.5
1.6
Summary
(a) Crop production intensification is needed but options need to be targeted for improved impact
(b) There is limited scope for CA for most farmers in
southern Africa - adoption currently does not exist
(c) Maize–legume intercropping has potential to push the boundary of crop production and reduce the risk of total crop failure
(d) Cattle manure need to be applied in combination with fertiliser and targeted to fields where crop responses are large
(e) External ideas should be used to stimulate local innovations in search of locally adapted solutions for improved crop productivity
Climate smart cropping systems
Climate Smart Cropping Systems (CSCS) must remain productive and profitable under variable weather circumstances, weather shock and projected climate conditions.
High resource efficiency • Water• Nutrients
CSCS should reduce GHG emissions (CO2).
Why Conservation agriculture?
Why intercropping?
Vunduzi (2009/10 season)
Days after planting
0 20 40 60 80 100 120 140 160
Cum
ulative rainfall (mm
)
0
200
400
600
800
1000
54 Days
• Relay intercropping reduces climatic risk of total crop failure
Research objectiveTo explore alternative
cropping and farming
systems for increased
productivity, efficiency,
resilience and adaptive
capacity of smallholder
farmers in SSA.
Framework to develop a climate smart cropping systems (CSCS).
Modelling approach………….
The seasonal analysis option of DSSAT model will be used to predict the response of maize and or legume under the three climate scenarios
DSSAT - Simulates growth and development of a crop growing on a uniform area of land under prescribed management and soil conditions.
Parameterization of the DSSAT crop growth model to explore scenarios of performance of maize-based cropping system under possible climate and weather pattern
Data sources – experimental data
CIMMYT long-term on-farm and on-station trials under ‘CA’ in Malawi, Mozambique, Zambia and Zimbabwe
Experiments been running since 2004/2005 season
Tillage, mulching, fertility, rotation
Climate change scenarios - MarskSim
• BCCR_BCM2.0, CNRM-CM3, CSIRO-Mk3.5, ECHam5, INMCM3.0, MIROC3.2 (medres)
• AVERAGE (CNRM-CM3, CSIRO-Mk3.5, ECHam5, MIROC3.2 (medres))
Expected outputs
Quantified impacts of climate change on the perfomance of current and novel farming systems
Cropping systems and resource allocation domains for farming systems adapted to future climate conditions
Several peer reviewed manuscripts
Collaborations (SIMLESA, COMESA, ABACO, DREAM, CCAFS, UR SCA, UMR Innovation, GCAP-CIMMYT)
Who am I ? …………my family
Dalitso Thabo5 years
Steve Melusi8 weeks
Gra
ce