Economic Implications of Extreme Heat Effects on Rice Yield and Milling Quality in Arkansas

Future increases in global surface temperature threaten those worldwide who depend on rice production for their livelihoods and food security. Past analyses of extreme heat effects on rice production have focused on paddy yield and have not accounted for the detrimental impact of extreme heat on milling quality outcomes which ultimately determine edible (marketable) rice yield and value. Using rice yield and milling quality data on six popular rice cultivars from Arkansas, USA, combined with on-site, half-hourly and daily temperature observations, this study finds a nonlinear effect of extreme heat exposure on yield and milling quality. A 1 °C increase in average growing season temperature reduces paddy yield and producer revenue by 8.2%; total edible rice yield by 9 to 9.9%; high-quality edible rice yield (kg ha-1) by 10.4 to 15.6%; and total milling revenue by 11.1 to 38.7% across genotypes. Utilization of the significant annual and locational temperature variability in the dataset allows examination of further mean growing season temperature increases of 2 and 4 °C. Results show that failure to account for changes in milling quality leads to significant understatement of the impacts of extreme heat on rice production outcomes