An assessment of climate variability and change and its effects on millet yields in Paicho sub county, Gulu District

Abstract

Climate variability and change are generally expected to adversely affect crop yields and livelihoods of agro-dependent societies especially in Sub Saharan Africa (SSA). However, there remain gaps on the dynamics of the expected regional climatic changes and impacts on key food security crops. In this study, an assessment of historical and projected climatic conditions and expected changes in millet yields for Paicho S/C up to the year 2033 was undertaken. Also assessed were the coping, adaptive and institutional roles with respect to climate change threats in the region. The study adopted a cross sectional survey design and engaged a compendium of methods to realize the formulated objectives. To determine historic climatic trends, rainfall and temperature data for 32 years and 19 years respectively was obtained from the Department of Meteorology of Uganda and subjected to trend analysis. For future climate, the PRECIS (Providing Regional Climates for Impact Studies) model was used based on projected conditions at a 50 km spatial resolution. The projected climate outputs from the PRECIS model were input in the Penman Grindley model to simulate future millet yields under changed climatic regimes. To elicit coping and adaptation measures, household interviews based on a statistically determined sample of 147 respondents were conducted. This was subjected to a range of statistical analysis techniques including regression analysis and cross tabulations to generate relationships as well as descriptive statistics. Differences in means were detected at a 95% confidence level. The results indicate seasonal and decadal variations in rainfall amounts while annual rainfall amount remained quasi uniform (P>0.05) for the period 1980-2010) implying that the area is currently contending more with climate variability rather than climate change. In general, the area receives adequate annual rainfall amount of over 1150mm which should be supportive to crop growth and abundant yields. However, the rainfall is distributed in one long season spanning from March to October and characterized with inconsistencies in amounts. Both mean annual maximum and minimum temperature trends show a statistically strong and significant increase (p<0.05). Comparatively, the minimum temperatures have varied more than the maximum temperatures. PRECIS projected changes for 2033 reveal a strong and significant decrease in rainfall (p< 0.05). This is likely to decrease millet yields by 2.6% below the average current yields of 1.8t/ha/yr under the business as usual scenario. The current coping mechanisms to climate variability and change in the community include buying food (27%), exchange of labor for food (25%), and getting food help (21%). The major adaptation strategies to climate change include; getting jobs outside agriculture (20%), adjusting planting dates and diversifying production (19%) and mixed cropping (15%). Existing institutions include; Local councils, clan/elders networks, family networks, religious institutions, NGO’s and CBO’s. Their major roles include; governing entitlements to key resources, decision on planting dates, limiting tree cutting and bush burning, access to credit and relevant information regarding climate variability and change.