1Department of Geography, Environmental Management and Energy Studies, University of Johannesburg, Auckland Park, South Africa.
2School of Geography, Archaeology and Environmental Studies, University of Witwatersrand, Johannesburg, South Africa.
3South African Medical Research Council, Biostatistics unit, Durban, South Africa.
This paper investigated the response of major food crop yields namely beans, cassava, Irish potatoes, maize and sweet potatoes to ongoing changes in climate in Rwanda. The projected daily precipitation and temperature data for the period 2000-2050 used in this study were generated by stochastic weather generator (LARS-WG) from daily raw data for the period 1961 -2000. These data were collected from Rwandan Meteorological Center based in Kigali, while the agricultural records for the period 2000-2010 used to project yields of major food crops for 2011-2050 were obtained from the National Institute of Statistics of Rwanda and the Ministry of Agriculture and Animal Resources. A number of statistical techniques were applied in projecting the major food crops yields and attempting to quantify their magnitude trends in response to projected precipitation and temperature data. The climate and soil suitability analysis revealed that the central plateau and south-west regions of the country will be the most suitable regions for cultivation of major food crops except Irish potatoes which can be grown in the north-western highlands. The central plateau region is the only region that is expected to experience an increase in yields for most of the major food crops under investigation. The south-west region will have increased beans, cassava and sweet potatoes yields in season A (September-January). The eastern lowlands are expected to register a decreasing trend in most of crops yields in season A, corresponding to the anticipated decline in mean rainfalls and number of rainy days. The envisaged yields increase in season B (February-June) for beans, maize and Irish potatoes will be in response to a rise in mean rainfall and number of rainy days. Heavy rainfall in the north-western region is likely to have a negative impact on crop yields. The rain might cause waterlogging, flooding events and landslides which may damage and destroy the crops.