Transcript Country Report Kenya

Anticipated Climate Change and Impact
on Kenyan Agriculture
E. Gacheru , P. Gicheru
C. K. Gachene .
and L. Claessen
General overview
Climate change and Agriculture
• “Climate change. a serious global risks, demanding urgent global
response” Stern review 2006)
• Global warming trend for Africa (0.50C-20C) % 10% reduction in
rainfall
•
Agriculture sector from developing countries most vulnerable
• Africa is the most affected by negative impacts (TAR ,IPCC 2001)
• Vulnerability and adaptation challenges highlighted by TAR IPCC
2001
• Contributing to further deterioration existing challenges ( PCC 2001;
Mathews et al 2007, UNFCCC, 2007;DFID, 2006)
-
land degradation
food and water insecurity
poverty and HIV/AIDS
Observed Temperature Changes in Africa (Source: IPCC (2001)
Climate Change 2001, Impacts, Adaptation and Vulnerability)
Kenya
• Situated at the Eastern coast of Africa
• Neighbours, Sudan & Ethiopia, north; Somalia east; Uganda,
west; and Tanzania in the south
• Area ~582 km2 ; Popn 28.7 mill (1999 census)
• Agriculture main stay of Kenyan economy
-26% GDP
-60% foreign exchange
- Employment to 75% of counties labour force
-Lifeline for 85% of population
- Generates 60% of foreign exchange earnings
Agricultural production systems
-Mainly mixed farming – raising of crops and livestock.
- More intensive high potential areas
-Maize main staple food crop,
-Dry bean most important legume crop.
- Coffee, tea, and sugarcane major commercial crops.
- >75% agriculture practiced by small holder farmers
Importance of Potato and Sweet
potato
Sweet potatoes (Republic of Kenya 2006)
– important food security crop after cassava
– Mainly grown in, Nyanza and western and central province
– Production increased from 546,309 in 2004, to 671,709 in
2005
• Irish potatoes (republic of Kenya 2006)
– Ranked second as staple after maize and 5th among the 20
most important agric commodities
– Grown in the high altitude zones of central province, eastern
(Embu, Meru and Machakos*) and rift Valley
– Grows best between 1500m to 3000m
– In urban areas, utilization indicates improving standards of
living
Kenya
Divided into seven agro-climatic zones (ACZ) based on suitable area for
growing major food and cash crops. 18 % high agriculture potentials &
80% ASAL
ACZ
CLASS
RAINFALL
(mm)
I
humid
1100-2700
II
Sub-humid 1000-1600
III
Semi
humid
800-1400
IV
Sh-SArid
600-1100
V
Semi Arid
450-900
VI
Arid
300-550
VII
V Arid
150-350
Climate change concerns in Kenya
Observed and anticipated Climate change in Kenya
Period
Temp
∆ (0C)
∆ in Rainfall
(mm)
GCM
1869-2000
0.9
-91.8
Observed
2000-2100
5.9
+213
HadCM3LC
By 2030 (AEZ
III-IV)
2.89
Variation LR(-)
SR (+)
GFDL
By 2030 (AEZ
III-IV)
2.29
Variation LR(-)
SR (+)
CCCM
By 2030
3.5
-
CCCM
4.0
-
GFDL
0.350.5
-
Observed
Mean for 19371968 vs 19812000 LM &LL
Zones E. Kenya
Source
Falloon et al
2007
Mati 2000
Mariara &
Karanja 2007;
Karanja 2007
Jaetzod 2006
Impacts of climate change; on agriculture
productivity
– Increased temperature and reduction in precipitation expected to
reduce crop
– Impact will vary from zone to zone
– Increased temperature is more critical than rainfall (Mariara &
Karanja 2007)
Predicted impacts on net revenue by Zones, Richardia analysis in (US$
ha-2)
Climate Scenario
Medium & low
potential
Zones
High
potential
All zones
+3.5 0C
80.05 (24%)
-3.54 (-1%)
68.45 (20%)
+4.00C
108.79 (32%)
11.91 (3%)
93,04 (27%)
20% reduction in rainfall
69.54 (21%)
20.14 (7%)
24/39 (7%)
+3.5 0C+ 20% reduction in
rainfall
149 (44%)
32.05 (27%)
92.84 (27%)
+4.00C+20% reduction in
rainfall
178.33 (53%)
32.05 (9%)
117.43 (34%)
source Mariara and Karanja 2007
Impact continued
Increased temperatures and reductions in precipitation will increase
crop water requirement
Impact of climate change in water use in Kwale district
Crop
Beans
Scenario
ET0
(mm)
ETm
(mm)
Ya
Ym
ETA (mm) % ∆ in
crop
water use
IWR
Original
509
321
471
2500
94.4
19
CCCM-LR
559
352
471
2500
103.7
9.8
29.3
CCCM-HR
559
352
471
2500
103.7
9.8
21.5
GDFL-LR
566
357
471
2500
105.1
11.3
30.1
GDFL-HR
566
357
471
2500
105.1
11.3
22.2
Original
663
444
1137
9000
133.7
CCCM-LR
727
487
1137
9000
146.6
9.7
93.1
727
487
1137
9000
146.6
9.7
72.8
GDFL-LR
735
493
1137
9000
148.3
10.9
95.1
GDFL-HR
735
493
1137
9000
148.3
10.9
74.7
Maize CCCM-HR
(Adapted from Karanja 2007)
61.3
Adaptation
• Policy/national level ( TNA 2000)
Increased frequency and intensity of extreme events has
contributed to an increased awareness of impacts of climate
Examples of effort to responded include
– Formation of the National Disaster mgt Authority
– Crop early warning systems
– Dissemination of weather & climate information ( Radio
internet& the formation of the Kenya Network of Journalists
& Meteorologists
– Formation of a Inter-Ministerial Committee on Environment,,
– Plant breeding drought/disease tolerant crop varieties
At community level examples include
– crop diversification,
– different dates of planting,
– irrigation, water
– conservation and tree planting
Lack of capital/credit a constraint to adaptation
Predicted impacts and adaptation effects
on maize Yield
Site
Homa
Bay
Paponditi
Kichaka
Simba
Kampi ya
Mawe
Climate Model
Yields for different planting dates
Original
15th
Feb
1st March
15th
March
1st April
15th April
Normal climate
5813
4740
1500
0
77
CCCM ((2xCO2)
6684
5652
3534
296
0
GDFL( 2xCO2)
6609
5538
3724
474
0
Normal climate
1559
1407
1149
821
158
CCCM ((2xCO2)
1337
633
1416
1692
396
GDFL( 2xCO2)
1112
558
949
1644
554
Normal climate
2056
2399
2393
2166
2190
CCCM ((2xCO2)
1988
2402
2566
1966
1861
GDFL( 2xCO2)
1820
2185
1800
1848
1217
Normal climate
1153
343
123
0
0
CCCM ((2xCO2)
1881
1293
608
7
216
GDFL( 2xCO2)
1440
1306
420
0
322
Adapted from Mati 2000
Study Title
Effects of farmers resource endowment,
anticipated temperature increase and rainfall
variation, on soil Organic carbon and intern
its effect on potato and sweet potato yields
in Eastern Kenya
Justification
•
Exacerbation of existing vulnerability/ challenges of poor farmers
(land degradation, food insecurity, pests & diseases)
•
Warmer temperatures /hydrological changes are likely to affect soil
processes (SOM) mineralization and other processes that affect soil
fertility (IPCC 2007).
•
Technologies that may assist farmers reduce the anticipated global
warming impact available
•
•
•
•
•
Impact of climate change on agriculture Ecosystem
Climate change may impact directly or indirectly on ecosystems
Direct effects
• Temperature; Rainfall amounts/distribution
Indirect
Human activity as they respond to climate change
• Change of crop/diversification and change in mgt
Som whose dynamics is driven by climate, plays an essential role in
in determining soil fertility and productivity
Justification
Earlier studies on climate change and agriculture
• Looked at individual systems in isolation and failed to consider other
interacting factors (Cohen et al 1994)
• Earlier studies on climate change and agriculture emphasized on
crop response and impacts on food security and failed to consider
other interacting factors like soil fertility (Parry 1990; Morton
2000)
• In Kenya most available information is on impacts; on agriculture in
general or cereals
• Developing countries have different and unique circumstances, such
as variable biophysical conditions, social cultural and economic
situation that influence the impacts of climate change (Fischer and
Velthuizen 2003).
• Shepherd and Soule 1998 reported variation on soil nutrient
balances in western Kenya based on resource endowment; with low
and medium resource endowment farms indicating negative nutrient
balances,
Justification continued
In order to develop effective, such heterogeneity must be put
into consideration when designing climate change adaptation
strategies.
• Also the differences in adaptation capacity/options between
the poor and wealthy need to be considered.
• Understanding on how systems will respond to change
(Adaptation) is crucial in reducing vulnerability to climate
change
• The relevance adaptive strategies to climate change impacts to
a given region/community
• Agriculture should be managed to enhance ecosystem services
beyond production (The millennium ecosystem service evaluation
2007 )
Objectives
•
Broad objective
Assess the effects of temperature, precipitation and farmers’
resource endowment and soil mgt on soil organic carbon and
the effect of soil organic carbon on sweet potato and potato
yields in different AEZ.
Specific objectives
To assess the role of farmers’ resource endowment and soil
fertility mgt on soil organic carbon
To determine the impact of anticipated temperature and
precipitation due to climate change on soc and nitrogen
dynamics in different AEZ
To determine the yield of potato and sweet potato varieties under
varying soil organic matter content in small holder farms of
Easten of Kenya
To assess the interaction effects of climate change and soil
fertility on selected potato and sweet potato varieties yield in
small holder farms in Kenya
To analyse the potential contribution of potato and sweet potato to
climate change adaptation of small holder farms in Kenya
farming systems
Materials and Methods
• a) Literature review (Climate change analogies)
• Analogues scenarios represent possible future climate based
on observed climate regime in space or time
• This method have advantages over controlled conditions (Lab
and green house) by providing ecosystem microclimate
dynamics and cheaper( Harts & Perry 1999)
• Even small changes in temperature will affect N cycling
(Harts and Perry 199
• Using spatial analogue, Bottnier et al 2000, estimated a
possible C mineralization of 25-25% with a temperature
increase of 30C
Materials and methods continued
• Role of resource endowment and soil fertility mgt on
SOC
Participatory wealth ranking, Participatory Learning and action
research (PLAR) for soil fertility mgt classification and soil
sampling
• Impact of climate change on soc
Using PCV soil cores, soil will be tran-slocated across a AEZ
transect and soc and N dynamics monitored (See Harts and Perry
1999, Harts 2006, Bottner et al 2000)
• Potato and sweet potato yield trials
Farms will be selected on the bases of soc content and the
performance of yield performance of potato and sweet potato
determined
Analysis of adaptation potential
Using down scaled data from GCM, climate change analogue
procedures the impact of climate change on soc, N dynamics and
adaptation potential of potato and sweet potato will be analysed
Study area (Embu,Mbere Meru districts
Characteristics
District
Embu
Mbeere
Meru Central
Size (km2)
729
2097
2982
Administration divisions
6
4
11
Population
278196
170,953
498880
Population density
381
82
167
Arable land (km2)
300.1
1695
1952
0.86
4.8
Main AEZ
UM1-3
LM3-5
UH1-2, UM1-3,
UM2-5, LM2-5
Area cover (ha)/or %
133.9 (67%)
1813 (86%)
Several AEZ
Altitude
600m in Mbeere - 2100m Embu
750M -2900
Mean temperature (0C)
15.8 in UH to 25.5 in LM
11.7-20.6
Rain fall (Bimodal)
640mm in Mbeere -2200mm Embu 500mm-2600mm
Ave Farm size (ha)
AEZ and soil types Embu & Mbeere districts
Farming system Embu and Mbeere
•
EMBU
– , mixed livestock system.
– Land use varies with AEZ
– Cash crops /tea and coffee(40%landa rea
– Declining yields
– Important food crops Maize, beans and potato
– At individual farm occupies 30%, 15 and 7% respectively
•
Mbeere
-Most of the district is marginal land
- 48% of population depend on mixed farming and 56% marginal
mixed livestock and farming
- Main food crops-maize, beans, cowpea pigeon peas,
Meru central
•
•
•
•
•
•
Land use
International level -Conservation of forest/national parks
National level-part of national food and cash crop basket
Cash crops-tea, coffee, tobacco, & horticultural crops
1000 farms> 20 ha and 8100 less than 2 ha
In 2002, 39\000, 40,00 and 15700 ha grown to Maize,
beans and potato respectively
• Potato production threatened by incidences of bacteria wilt,
blight & potato moth