Anticipated Climate Change and Impact on Kenyan Agriculture

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Anticipated Climate Change and Impact on Kenyan
Agriculture
E. Gacheru , P. Gicheru C. K. Gachene . and L.
Claessen
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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, 2007DFID, 2006)
• - land degradation
• - food and water insecurity
• - poverty and HIV/AIDS

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Observed Temperature Changes in Africa (Source
IPCC (2001) Climate Change 2001, Impacts,
Adaptation and Vulnerability)
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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.
• - gt75 agriculture practiced by small holder
  farmers

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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

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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
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Climate change concerns in Kenya
Observed and anticipated Climate change in Kenya
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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)
source Mariara and Karanja 2007
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Impact continued
Increased temperatures and reductions in
precipitation will increase crop water requirement
Impact of climate change in water use in Kwale
district
(Adapted from Karanja 2007)
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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

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Predicted impacts and adaptation effects on maize
Yield
Adapted from Mati 2000
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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

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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

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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,

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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 )

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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

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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

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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

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Study area (Embu,Mbere Meru districts
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AEZ and soil types Embu Mbeere districts
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Farming system Embu and Mbeere

• EMBU
• , mixed livestock system.
• Land use varies with AEZ
• Cash crops /tea and coffee(40landa 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,
  

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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 farmsgt 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

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Asanteni