Comparison of rice yield potential in Ethiopia and in northern Japan: an experimental and modeling study

Abstract

　Ethiopia, a tropical highland region, is an important cool-climate rice-production region. Limited information is available on rice yield potential in Ethiopia. This study aimed to compare rice yield potential from experimental and modeling studies in Ethiopia and Japan. Experimental potential yield (PY_E) was evaluated from field trials in the Fogera plain in Ethiopia and in northern Japan, both cool-climate regions, using the same two cultivars under optimal conditions during the 2023 cropping season. Climatic potential yield (PY_C) was estimated by a weather-driven crop growth model. The gap between experimental and national yields was estimated. The PY_E in Ethiopia was 30% lower than that in northern Japan. This decrease was similar to the difference in PY_C between Ethiopia and northern Japan. The national yield, relative to PY_E, was 56% in Ethiopia, versus 90% in Japan. It was concluded that lower national yield in Ethiopia than Japan can be attributed to PY_C and the gap from PY_E. The combined use of experimental and modeling studies represents a useful approach for evaluating the national crop productivity from a climate perspective. Our results will support future strategies to improve rice productivity in Ethiopia.