Impacts of projected changes and variability in climatic data on major food crops yields in Rwanda

This paper investigated the response of major food crop yields namely beans,cassava, Irish potatoes, maize and sweet potatoes to ongoing changes in climate inRwanda. The projected daily precipitation and temperature data for the period2000-2050 used in this study were generated by stochastic weather generator(LARS-WG) from daily raw data for the period 1961 -2000. These data werecollected from Rwandan Meteorological Center based in Kigali, while theagricultural records for the period 2000-2010 used to project yields of major foodcrops for 2011-2050 were obtained from the National Institute of Statistics ofRwanda and the Ministry of Agriculture and Animal Resources. A number ofstatistical techniques were applied in projecting the major food crops yields andattempting to quantify their magnitude trends in response to projected precipitationand temperature data. The climate and soil suitability analysis revealed that thecentral plateau and south-west regions of the country will be the most suitableregions for cultivation of major food crops except Irish potatoes which can begrown in the north-western highlands. The central plateau region is the only regionthat is expected to experience an increase in yields for most of the major food cropsunder investigation. The south-west region will have increased beans, cassava andsweet potatoes yields in season A (September-January). The eastern lowlands areexpected to register a decreasing trend in most of crops yields in season A,corresponding to the anticipated decline in mean rainfalls and number of rainydays. 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 rainydays. Heavy rainfall in the north-western region is likely to have a negative impacton crop yields. The rain might cause waterlogging, flooding events and landslideswhich may damage and destroy the crops.