American Journal of Climate Change, 2020, 9, 228-242 https://www.scirp.org/journal/ajcc ISSN Online: 2167-9509 ISSN Print: 2167-9495 An Appraisal of Adaptation Measures to Climate Variability by Smallholder Irish Potato Farmers in South Western Uganda Frank Mugagga* , Alex Nimusiima, Julius Elepu Department of Geography, Geo-Informatics and Climatic Sciences, Makerere University, Kampala, Uganda How to cite this paper: Mugagga, F., Ni- Abstract musiima, A., & Elepu, J. (2020). An Ap- praisal of Adaptation Measures to Climate Climate change and variability are a reality and have had marked effects on Variability by Smallholder Irish Potato Far- both human and ecological systems. Adaptation to such effects either directly mers in South Western Uganda. American or indirectly is viewed as a novel way of reducing the spread of the associated Journal of Climate Change, 9, 228-242. https://doi.org/10.4236/ajcc.2020.93015 risks. The study was conducted in Rubanda District with a general aim of evaluating the effectiveness of adaptation measures to climate variability used Received: February 21, 2020 by smallholder Irish potatoes farmers. Specifically, we sought to appraise small- Accepted: September 5, 2020 holder Irish potato farmers’ perceptions about the effectiveness of climate va- Published: September 8, 2020 riability adaptation measures and implications on Irish potato productivity. Copyright © 2020 by author(s) and We undertook a cross-sectional study to collect data from total of 197 farmers Scientific Research Publishing Inc. using a structured questionnaire. Other participatory methods such as focus This work is licensed under the Creative group discussions and key informant interview were also used to complement Commons Attribution International License (CC BY 4.0). the household survey. Data were analyzed using SPSS Version 23 to generate http://creativecommons.org/licenses/by/4.0/ descriptive statistics as well as relationships between the adaptation measures Open Access and the productivity of the Irish potatoes using a Cobb-Douglas production function. The Cobb-Douglas model revealed that the use of fertilizers was significantly and positively associated with productivity of Irish potato (P < 0.001). Furthermore, Smallholder Irish potato farmers perceived the use of technology, terracing, early planting and application of fertilizers as the most effective climate variability adaptation measures. The study recommends that measures that are cost-effective, efficient and coherent should be promoted to offset the impacts of climate variability which would include the adoption of improved potato varieties and use of fertilizers with proper management of erosion. Off-season planting of Irish potatoes in the wetlands should be dis- couraged by the local administration and the National Environment Man- agement Authority. This calls for a collective action involving the agricultural practitioners and inline civil society organizations to ensure that farmers have access to such inputs. DOI: 10.4236/ajcc.2020.93015 Sep. 8, 2020 228 American Journal of Climate Change F. Mugagga et al. Keywords Adaptation Measures, Climate Variability, Efficacy, Irish Potato Farmers, South Western Uganda 1. Introduction Uganda’s climate is naturally variable and is susceptible to impacts of climate variability such as floods, landslides and drought among others (Hepworth & Goulden, 2008; NAPA, 2007; Mugagga et al., 2019). These events are already having negative socio-economic impacts such as water scarcity, proliferation of pests and diseases, and reduction in crop yields (Ampaire et al., 2017; CDKN, 2015). Kikoyo & Nobert (2015) revealed that average annual temperatures have been increasing at a rate of around 0.3 degrees per decade in most parts of Uganda since 1970 while rainfall does not show any significant trend in the same period but is highly variable from year to year. For example, Hepworth (2010) observed that rainfall in Uganda is expected to increase by 14% or fall by 7% below the 1970-1999 average by 2030. The implications of these changes in rainfall and temperature will be significant for food security and rain-fed agriculture which is the main source of livelihood among the rural farm households (Hepworth & Goulden, 2008; Kikoyo & Nobert, 2015). Studies show that there is a strong rela- tionship between climate variability and quality of Irish potato farming in many regions in Africa (Hijmans, 2003; Karanja et al., 2014). For example, high tem- peratures cause a decrease in tuberisation and heavy rains damage potatoes. Byishimo (2017) observed that an increase in maximum temperatures by 1˚C may lead to a decrease of potato yields by 31.8% in Rwanda. These changes will cause a decline in Irish potato yields and yet the crop is an important food and cash crop in Uganda and one of the dominant crops in South-Western Uganda, with over 80% of smallholder farmers in Rubanda District involved in it (MAAIF, 2010; Mbowa & Mwesigye, 2016; Mugagga et al., 2019; UBOS, 2016). A study by Byamukama et al. (2018) revealed that climate variability related disasters like droughts and floods are key factors affecting potato growing in Rubanda Dis- trict. Adapting to these changes is therefore key given that the calculated de- crease in potato yields is large for many regions without adaptation by 2040 to 2060 (Hijmans, 2003). Farmers have adopted measures to counter the climate variability risks (Hisali et al., 2011; Kikoyo & Nobert, 2015; Mugagga et al., 2019; Twagiramaria & Tolo, 2016), however the effectiveness of such adaptation meas- ures and their impact on crop production is not yet well understood in Rubanda District. A few studies (Kikoyo & Nobert, 2015; Zizinga et al., 2015) conducted in Uganda to measure the performance of adaptation strategies further highlight the need for research into effectiveness of adaptation measures employed by farmers. Kikoyo & Nobert (2015) revealed that adaptation measures applied by DOI: 10.4236/ajcc.2020.93015 229 American Journal of Climate Change F. Mugagga et al. farmers in Uganda are questionable in terms of their effectiveness. This limited knowledge is also spelled out in the Uganda Climate Action Report (2015). This exemplifies a plausible gap in scholarship to which this study sought to address. According to Brooks et al. (2011), success of adaptation measures can be measured in terms of efficacy, efficiency, acceptability, equity and implementa- bility. Effectiveness has been observed as major criteria for evaluating the success of adaptation measures (Regmi, 2018). Effectiveness is the capacity of a system to adapt to achieve its objectives and it involves a reduction of impacts, expo- sure, risks and the avoidance of danger (Adger et al., 2005; Regmi et al., 2018). The study set out to appraise effectiveness because it relates to how successful an intervention is in delivering intended results. In order to achieve this, we sought to appraise smallholder Irish potato farmers’ perceptions about the effectiveness of climate variability adaptation measures and implication on Irish potato prod- uctivity in Rubanda District 2. Conceptual Framework The study hinges on the economic theory of production. The production func- tion (PF) describes the relationship of transformation of inputs into outputs given the available level of technology that the farmer has (Gorgess & Naby, 2012). Under given technological conditions, farm output is viewed as a function of farm size, labour, capital and other variables such as for example weather, agronomic practices and farm management practices. To put in the context of climate variability, the output production is viewed as a function of the tradi- tional factors of production (land, labour and capital) and the different response mechanisms that a farmer applies to counter climate variability. These could in- volve application of fertilizers, use of improved seed varieties, timely planting and water harvesting. Given its importance, several studies (Adams, 2005; Dharmasiri, 2009; Gor- gess & Naby, 2012; Kotulič & Pavelková, 2014; Prasad & Wagle, 2016) have ap- plied the production function to unravel the interrelations between inputs and outputs of production; More so because of its ability to describe the rate at which resources are transformed into products (Kotulič & Pavelková, 2014). The most common of the production functions used to analyse the effective- ness of smallholder agricultural production is the Cobb-Douglas Production Function because of its superiority over the other functions. It is linear in loga- rithm transformation, empirically simple, computerization feasibility and ade- quate fit to data (Asefa, 2011; Bhanumurthy, 2002). More so, the elasticity of production and marginal productivity helps to establish the productivity of in- put factors (Dharmasiri, 2009). This model was also used because of its ability to model productivity (Prasad & Wagle, 2016). The theory behind the study hinged on the household’s ability to make a pro- duction decision on the available adaptation measures such as mulching, irriga- DOI: 10.4236/ajcc.2020.93015 230 American Journal of Climate Change F. Mugagga et al. tion, fertilizers, improved crop varieties, borrowing and timely planting to pota- to production. However, along the decision making process are economic, environmental and social factors that affect the effectiveness of the adaptation process. Effec- tiveness of adaptation in terms of increasing the productivity of Irish potatoes would be achieved if