Climate change impact on land suitability for rainfed crop production in Lake Haramaya Watershed, Eastern Ethiopia

Understanding the effects of climate change on land suitability for crop production has become an important issue with respect to food security. The main objective of this study was to evaluate the impacts of climate change on land suitability for rainfed crop diversification under current and future climate change scenario in Legambo sub-watershed. Land utilization types (LUTs) selected for this study were, sorghum (Sorghum bicolor L.), maize (Zea mays L.), bread wheat (Triticum aestivum L.), sweet potato (Solanum tuberosum L.) and soybean (Glycine max L.). MicroLEIS DSS through the application of Almagra and Terraza models were used. Almagra model assesses the suitability of different soil types to a specific crop. Terraza model provides an experimental prediction for the bioclimatic deficiency. Soil morphological and analytical data were obtained from 4 representative soil profiles and stored in the SDBm database. Agro-climatic data, referred to temperature and precipitation (monthly average values) for 20 consecutive years (1995-2014), were obtained from National Meteorological Agency and incorporated to the CDBm database. A future scenario of climate change was calculated according to the predictions of Intergovernmental Panel on Climate Change (IPCC) on regions of East Africa under scenario RCP8.5 by 2100. The results show that, the most suitable crops to grow in the study area are sweet potato >sorghum >maize>soybean>wheat in respect of that order. The main limitation factors for land suitability are soil texture and drainage conditions. Bioclimatic deficiency evaluation showed a positive response to climate change, with percent yield reduction decreasing. Accordingly, results show the following trend from low to high suitability to climate change: sorghum> maize> sweet potato>soybean>wheat. The net effect of climate change on land suitability is positive for both hypothetical scenarios and therefore, the study area is suitable for rainfed crop production for the selected LUTs.