Impacts of climate change and variability continue to be felt in Uganda as manifested by recent floods in the Teso sub region and Kasese, landslides in Bududa and prolonged droughts in the Karamoja sub region, all of which severely impact on food security in the country. Agriculture in Uganda, being rain-fed, is adversely affected by climate change often leading to substantial crop failure and/or crop losses. Much of this is attributed to highly erratic rains during the growing seasons. Flash floods and strong winds have accelerated soil erosion which threatens sustainable agricultural production. Soil erosion is also accelerated by deforestation, overgrazing and other poor farming methods. In some areas, crop cultivation is done up to stream banks causing siltation. Also to be noted is that Uganda, like other developing countries, lacks comprehensive long-term meteorological data. Most of the historical station weather data have gaps as a result of stolen or old equipment and shortage of trained observers. This confounds analysis of climate change trends, extremes and related risks.
In regard to the challenges above, studies on land use and soil carbon stocks have been done and show that natural forests, when compared to other land uses, store the highest amount of soil carbon (146 t ha-1). The implication is that they can be used as carbon sequesters/sinks in mitigating against the adverse effects of anthropogenic climate change and thus need to be conserved. In addressing the soil erosion concern, specifications for soil and water conservation measures, especially mulching have been developed and tested in drought prone areas of western and central Uganda. In order to overcome soil moisture stress and soil erosion, the combination of manure and mulch is highly recommended for uptake by crop farmers as it can potentially reduce soil and water losses by up to 18.5 kg ha-1 and 2,340 l ha-1 respectively when compared to farmers’ up-and-down cultivation practice. Other measures being promoted in water catchment areas of Sembabule, Rukungiri and Isingiro, include agro-forestry trees (Caliandra, Grevellia Robusta), napier grass (Pennisetum Purpureum) and water retention trenches. These interventions are also known to restore soil fertility in degraded lands. In addressing drought, valley tanks/ dams have been constructed to enable local communities harvest rainwater as a way of coping with water shortages during the long dry spells. In regard to the highly unpredictable rainfall, adjustment algorithms to harmonize historical climate data have been developed that help bridge the existing data gaps. From this data, hotspot maps of rainfall/ temperature change have also been generated. Seasonal rainfall characteristics (onset, cessation and length of growing period) based on long-term estimations and analogue forecasting methods have been computed for 4 rainfall zones in Uganda to help farmers make informed decisions and also aid in early warning/ forecasting.
Oratungye J. K., Oludhe, C., Manene M. M. and Komutunga E. (2016). A multivariate analysis approach in determining potential hotspots of seasonal rainfall change over Uganda. International Journal for Research in Mathematics and Mathematical Sciences. 1(12):1-17
Akodi, D., Komutunga, E., Agaba, C., Oratungye, J. K. and Ahumuza, E. (2016). The effect of land use on soil organic carbon stocks in Lake Victoria Crescent Agro-Ecological Zone, Uganda. Journal of Agricultural Science and Technology A. 6(3):154-160
Komutunga E., Tushemereirwe, W., Kubiriba, J., Namanya, P., Oratungye, J. K., Akodi, D., Agaba, C., Ahumuza, E. and Kamusingize, D. (2015). Physical Effectiveness of Soil and Water Conservation Technologies in Drought Prone Areas of Western and Central Uganda. Journal of Agricultural Science and Technology B. 5(8):523-529
Komutunga, E., Oratungye, J. K., Ahumuza, E., Akodi, D. and Agaba, C. (2015). New procedure in developing adjustment algorithm for harmonizing historical climate data sets. Journal of Dynamics in Agricultural Research. 2(3):21-30