Impact of recent climate change on cotton and soybean yields in the southeastern United States

Abstract

The Southeastern region of the United States (SE-US) is agroecologically diverse, economically agriculture reliant, and distinct from the twentieth-century warming trend. Considering the inextricable link between climate and agricultural production, it is necessary to quantify future environmental implications on economically important crops of cotton ( Gossypium hirsutum L.) and soybean [ Glycine max (L.) Merr.] in the SE-US. The current study used the fixed-effect model (panel data approach) for climate and yield studies, to assess the impact of climatic variables from 1980 to 2020 such as daily maximum temperature (T max ), minimum temperatures (T min ), and rainfall on cotton and soybean yields. The data from 11 states were averaged per growing season and results revealed significant variability in temperature and rainfall during the last four decades. The T max , T min , and rainfall shifted in the range of 0.46–0.50 °C, 1.30–1.45 °C, and 3.74–3.95 cm, respectively, during the cotton growing season (CGS) and soybean growing seasons (SGS). However, the annual rate of change in T max , T min , and rainfall from 1980 to 2020 was in the range of 0.011–0.012 °C, 0.031–0.034 °C, and 0.089–0.094 cm, respectively, during the CGS and SGS. Rainfall had no significant effect on cotton and soybean yields. A 1 °C rise in T min increased cotton yield by 20.8% while decreasing soybean yield by 31.6%. Alternatively, a 1 °C rise in T max decreased cotton and soybean yield by 10.3% and 25.6%, respectively. • The nocturnal temperature explained the overall heating trend for both Soybean and Cotton over the 41-years. • Rainfall had a positive effect on cotton yield but a non-significant negative effect on soybean yield. • The 1 °C incremental T min boosted the cotton yield while reducing the soybean yield. • The 1 °C rise in the T max decreased the cotton yield and reduced the soybean yield.