Anticipated Climate Change and Impact on Kenyan Agriculture

1. Anticipated Climate Change and Impact on Kenyan Agriculture E. Gacheru , P. Gicheru C. K. Gachene . and L. Claessen

2. 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

3. Observed Temperature Changes in Africa (Source: IPCC (2001) Climate Change 2001, Impacts, Adaptation and Vulnerability)

4. 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

5. 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

6. 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

7. Climate change concerns in Kenya Observed and anticipated Climate change in Kenya

8. 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

9. 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)

10. 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

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

12. 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

13. 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

14. 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,

15. 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 )

16. 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

17. 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

18. 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

19. Study area (Embu,Mbere Meru districts

20. AEZ and soil types Embu & Mbeere districts

21. 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, Farming system Embu and Mbeere

22. 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

23. Asanteni