effects of climate change and adaptation on crops...
TRANSCRIPT
Effects of climate change and adaptation
on crops and livestock in mixed farming systems
in southern Africa
Katrien Descheemaeker (WUR), Patricia Masikati (ICRAF),
Sabine Homann-Kee Tui (ICRISAT), Olivier Crespo (UCT)
Crop-livestock farming systems
Climate change Temperature, rainfall, CO2
Variability, extremes
Biomass production
Species composition
Herbage quality
Biomass production (grain + stover)
Crop suitability
Cropping patterns
Feed intake
Animal growth and health
Milk production
Fertility
Pests Weeds Diseases
Crop
Animal
Grazing land
Water resources
Climate Change Effects
on Mixed Systems
Nkayi District in semi-arid Zimbabwe
Maize-based crop-livestock farming systems - Low crop productivity; e.g. 0.7 t/ha for maize, 0.5 t/ha for sorghum
- Low livestock productivity; e.g. mortality rates 15%; < 1.5 l/cow/day
- High poverty levels; 76% poor and 22% extremely poor
- Food self-sufficiency: 3-10 months
High vulnerability
Nkayi District in semi-arid Zimbabwe
Small Medium Large
43%
38%
19% extremelypoor
poor
non-poor
Small Medium Large
Cultivated
land (ha)
1.4 2.0 2.7
Cattle (TLU) 0 5.4 13.9
Family size 6 7 7
Farm heterogeneity in Nkayi district
(TLU = tropical livestock unit)
Introduction
What is the likely impact of climate change for rural
households?
What are options for climate change adaptation?
Taking into account:
- Mixed farming systems: crops, grazing lands, livestock
- Heterogeneity in rural communities
Climate data
Historical (1980-2010): Mid century (2040-2070):
20 GCMs
Projected changes in temperature, precipitation
Crop Model
APSIM, DSSAT
Crop management: fertilizer, rotation,
varieties,…
Effects on on-farm crop production; rangeland
grass production
Livestock model
LivSim
On-farm feed production; rangeland biomass
Effects on livestock
production (milk, off-take, mortality rates)
Economic model TOA-MD
Household characteristics Agricultural production
Prices, costs
Economic effects of climate change and
adaptations on entire farms
Economic impacts Heterogeneous populations Types of households
Modelling framework
All households
(n=160)
Climate change Temperature, rainfall
APSIM Grass production
APSIM,DSSAT Maize Sorghum Groundnut Mucuna
LIVSIM Herd size Milk production Offtake Mortality Manure production
Crop
Livestock
Grazing land
Climate Change Effects
on Mixed Systems
Fertilizer rates
Sowing dates
Soil types
Farm size
Crop allocation
Herd size
Herd management
Rangeland area
Stocking rate
On-farm
fodder
availability
Potential
pasture
intake
Household information – 160 households, 3 types
Cow
LivSim structure
Inputs - Feed quantity and
quality
- Herd size & composition
- Herd management
Parameters - Breed characteristics
Cow Cow
Potential growth & intake
Nutritive requirements
- Maintenance
- Growth
- Gestation
- Lactation
Actual growth & intake
Outputs
- Milk
- Calves and offtake
- Manure
Cow
Herd
Model calibration and
performance
evaluation reported in
Rufino et al., 2009;
2011
Climate
10
Hot and dry
climate scenario
Graph design by Alex Ruane
Climate model classification for
Nkayi, Zimbabwe
Current system
11
Maize production: - Three soil types
- No inputs
Grassland production
poor average good
poor average good
Apsim calibration and evaluation:
- Rurinda et al., 2015
- Masikati et al., 2015
Current system
0.5 TLU/ha 2 TLU/ha
Model behaviour in current system:
- Range of initial herd sizes and stocking densities
- Medium and large households
Herd size
- Less variability compared to
crop yields
- Herd is very important
asset: saving, insurance,
draught power, manure
medium large
Current system
13
medium large medium large
Milk Manure
Climate change impact - crops
14
Maize yield
Sorghum
yield
Groundnut
yield
poor average good
poor average good
poor average good
Climate change impact - fodder
15
Maize stover yield
Grass production
in rangelands
Intake from the
rangelands
poor average good
Climate change impact - livestock
16
Milk production Calving rate
medium large medium large
Climate change impact - livestock
17
Offtake Mortality
medium large medium large
Adaptation
18
Maize; three soil types
Adaptation package 1:
- Micro-dosing on maize (17 kg N/ha)
- Introduction of forage legume crop Mucuna (Masikati et al., 2014)
Milk; two farm types
poor average good medium large
Adaptation
19
Calving rate
Adaptation package 1:
- Micro-dosing on maize (17 kg N/ha)
- Introduction of forage legume crop Mucuna
Offtake
medium large medium large
Conclusions
Integrated modelling framework: assess effects on crops and
livestock, whole-farm economics
Take into account farm heterogeneity
LivSim captures indirect effects of climate change through
changes in feed production
Future work:
- Analysis of extreme events
- Incorporate direct effects of temperature on heat stress in
animals
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