Climate Change and ENSO Effects on Southeastern US Climate Patterns and Maize Yield

Area of Science:

• Agricultural Science
• Climate Science
• Environmental Science

Background:

• Climate change and El Niño Southern Oscillation (ENSO) significantly influence global weather patterns and agricultural production.
• ENSO's effects on climate are location-specific, with strong connections to climate variability in the southeastern U.S.
• The combined impacts of climate change and ENSO on growing season climate and crop yields may exceed expectations.

Purpose of the Study:

• To investigate the influence of climate change and ENSO on non-irrigated maize yields in the southeastern U.S.
• To quantify the relationship between growing season temperature anomalies and maize yield suppression.
• To analyze yield variations across different ENSO phases and their connection to climate conditions.

Main Methods:

• Coupled historical monthly precipitation and temperature data with non-irrigated maize yield data (33-43 years).
• Analyzed yield suppression related to increases in growing season maximum temperature.
• Examined yield variations across ENSO phases (El Niño, La Niña, Neutral) from 1971-2013.

Main Results:

• A 1°C increase in southeastern U.S. growing season maximum temperature correlated with a potential maize yield suppression of approximately 15%.
• Yield suppression varied from -25% to -2% across locations, impacting the average southeastern U.S. yield trend since 1981 by ~25% (17 kg ha⁻¹ year⁻¹), primarily due to June temperature anomalies.
• Maize yields differed significantly among ENSO phases, with higher yields during El Niño. La Niña years exhibited higher maximum June temperatures and lower June precipitation compared to Neutral and El Niño years.

Conclusions:

• Location-specific adaptation strategies are crucial for mitigating the impacts of climate change and ENSO on maize production.
• Understanding month-specific growing season climate conditions influenced by both climate change and ENSO is vital for agricultural resilience.
• June temperature anomalies and precipitation patterns linked to ENSO phases are key drivers of year-to-year maize yield variability in the southeastern U.S.