ADAPTATION TO THE THREATS
OF CLIMATE CHANGE:
Plantation crops with special reference
to tea
MAJOR PLANTATION CROPS IN SRI LANKA
• Tea
• Rubber
744,000 ha
• Coconut
C
t
# 13% of the GDP
# 19% of the Export earnings
>15% from Tea
# 2.5 Million dependents
Smallholders
Estate workers
Statistical Pocket Book - Plantation Sector, 2008
Coconut
3000
2500
2000
Tea
1500
1000
500
Rubber
PRODUCTION - 2008
• Tea
: 317.7 million kg
• Rubber
: 129.2 million kg
• Coconut
: 2,909 million nuts
Year
20
08
20
06
20
04
20
02
20
00
19
98
19
96
19
94
0
Cocon
nut (Million nu
uts)
3500
Drought
1992
19
92
500
450
400
350
300
250
200
150
100
50
0
19
90
Tea & R
Rubber (Milion
n kg)
NATIONAL PRODUCTION
SENSITIVITY TO CLIMATE CHANGE
# Rain-fed crops
# Productivity depends on
Soil & Climate (Weather)
# Climate Change Consequences
Rainfall variations
Temperature rise
CO2 increase
SENSITYVITY TO CLIMATE CHANGE…..
Ideal weather
Annual Rainfall
Temperature
Tea
Rubber
Coconut
Rainfall
(mm/yr)
2500-3000
1650-3000
> 1500
Temperature
(oC)
18-25
23-28
27
Tea:
Critical
environmental
conditions
Temp: > 30oC; Rainfall< 1200mm/year
R bb
Rubber
Rainfall < 500mm over 6 months; More rainy days
Coconut:
Dry spells over two months
Climate
change
g
C b h d t A
Carbohydrate
Assimilation
i il ti
Respiration
Rainfall
Temperature
p
CO2
Evapo-transpiration
Pest/Disease infestation
Drought/Flood
Soil Erosion
Soil Degradation
Prooductivvity of P
Plantattion crrops
CLIMATE CHANGE IMPACTS…..
EFFECT OF RAINFALL ON YIELD -TEA
Rainfall (mm) & Productivity (kg/ha/month)
Opt.RF=Optimum Rainfall (mm/month)
M=Loss of productivity (kg/ha/month/100 mm RF deficit)
AER
WL
WM
IM
WU
IU
Opt.RF
Opt
RF (mm)
350±20
417±49
417
49
227±10
223±38
303±34
M
29±3
36±6
36
6
81±11
55±7
39±3
Wijeratne et al.-2007
EFFECT OF TEMP. ON TEA YIELD
Temperature & Monthly yield (kg/ha)
Yield (kg
g/ha/month)
450
y = - 508 + 63.7x -1.46x 2
R2 = 0.11
0 11
400
350
300
+15kg/ha/month/oC
- 9.6kg/ha/month/oC
250
200
150
100
50
0
10
15
20
22
25
30
35
Monthly Mean Temperature (o C)
Wijeratne et al.-2007
EFFECT OF CO2 ON TEA YIELD
CO2 vs Mean yield (WL)
Yield (g/bush//week)
Y
120
100
80
60
40
20
0
1
8
15
22
29
36
43
50
57
64
71
Weeks
ENRICHED
CONTROL
Wijeratne et al.-2007
CO2 Enrichment (600ppm) has given
33-37% increase in tea yield
TEA YIELD PREDICTIONS FOR 2050
Baseline
CGCM-A1F1
CGCM B1
CGCM-B1
HadCM3-A1F1
HadCM-B1
HadCM
B1
CSIRO-A1F1
CSIRO-B1
Ratnapura Kandy
N’Eliya
2489
2314
2380
2348
2419
2401
2472
2454
3108
3072
3130
3115
3167
3137
2217
2217
2228
2174
2189
2246
2245
Wijeratne et al.-2007
WL, WM and IU regions are more vulnerable to
adverse impacts of CC
IMPACT ON COCONUT & RUBBER
# Improved assimilation with CO2 increase
# Decline in Coconut Yield due to drought & heat
stress
# Decline in Rubber yield due to heavy rainfall
# Soil deterioration with erosion & loss of organic
matter
# Changes to pest & disease behaviour
ADAPTATION MEASURES
Adaptation measures:
# Preserve beneficial effects
# Minimize adverse effects
# No-regret strategies
# Economically viable
ADAPTATION MEASURES - TEA
Adaptation measures aim at:
• Crop Improvement
• Soil Improvement
• Improvement
I
off aerial
i l environment
i
Proposed adaptation measures
# Select most suitable lands for new/re-planting
# Use of drought & heat tolerant cultivars & crop diversification
p
& Irrigation
g
# Soil Improvements
# Planting & management of shade trees
ADAPTATION MEASURES - TEA
• Use of drought & heat tolerant cultivars
& crop diversification
# Selection of very suitable lands for new/re planting
# Diversification of marginal lands as energy/timber
plantations and thatch banks (green manure)
# Planting of drought/heat tolerant cultivars or improved
seed varieties and grafted plants
# Planting of a basket of cultivars in one land
ADAPTATION MEASURES - TEA
• Soil improvements and irrigation
# Improve moisture retention capacity
# Improve ECE
# Soil & soil moisture conservation
Physical methods and agronomic practices
# Improvement of organic carbon levels
SA
SALT/Burying
i off prunings/Composting/Mulching
i
C
i
l hi
# Rainwater harvesting techniques
# Irrigation during dry spells
ADAPTATION MEASURES - TEA
• Planting and management of shade trees
# Reduce temperature
pp y organic
g
matter
# Supply
# Planting of high & medium shade trees as recommended
# Management of shade trees according to changes of
weather
ADAPTATION MEASURES – COCONUT
Drought effects and Soil Degradation take high priority
# Selection of very suitable lands (new/re-planting)
#A
Avoid
id less
l rainfall
i f ll areas (new-replanting)
(
l ti )
# Soil & soil moisture conservation measures
# Improvement of soil organic carbon levels
g
tolerant cultivars
# Use off drought/heat
# Rainfall harvesting techniques
# Irrigation during dry weather
# Intercropping/Mixed cropping
ADAPTATION MEASURES – RUBBER
Soil Degradation and heavy rainfalls take high priority
# Soil & soil moisture conservation measures
# Improvement of soil organic carbon levels
# Intercropping/Mixed cropping
# Use of rain guards
Summary for plantation sector (with special
reference to tea)
# Plantation crops are vital for the economic and social
development of Sri Lanka
# Beingg rain-fed crops
p ggrown in all elevations & terrains
plantation crops are vulnerable to climate change
# Tea plantations at high elevations are predicted to receive
beneficial effects of climate change
# Climate change can adversely affect production of all 3
plantation crops at low elevations
# Good agricultural practices improving soil and microclimate
li t around
d the
th tree
t
crops minimize
i i i adverse
d
impacts
The End…