Potato is one of the most important food crops in South Korea, but the climate change impact on potato production is not clearly understood due to the complex topography across the nation. The climate change impact on spring potato was assessed with a fine-resolution (1-km) simulation using the SUBSTOR-potato model and five regional climate models based on the Representative Concentration Pathways 8.5. Compared to the current climate, the future climates were projected to be more favorable for the spring potato production, which contrasts the previous simulation studies using general circulation models with coarse resolutions (0.5-1.0°). Without any adaptations, anticipated warming was projected to decrease potato yield by -7.7% in the 2080s. However, growing season length (GSL) could be extended by 18.5 days with earlier planting, which eventually over-compensated the negative warming effect. With consideration of the CO2 fertilization effect, overall climate change impact could be up to +80% in the 2080s. In addition, replacing the current early cultivar "Superior" with mid-late cultivars will provide additional yield gain in the coastal areas. Meanwhile, in the inland areas, breeding of frost- and heat-tolerance cultivars will be required for additional yield gain. Still, cautious interpretation is needed since the CO2 fertilization effect might be over-estimated and that the farmers may not extend GSL as much as in the current study from the economic point of view (i.e., farmers may harvest earlier when the market price of potato is high). This study highlights that a fine spatial resolution is essential for the realistic simulation of the climate change impact in complex terrain.
Keywords: Climate change; Complex topography; Crop growth model; Earlier planting; Fine resolution; Potato.
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