Nonlinear Heat Effects in South African Maize

In South Africa, maize (Zea mays) plays a pivotal role in the agricultural economy and food security of the country, but climate change threatens the agricultural productivity of this crop. This study aims to estimate the change in maize yield associated with a 1°C and 2°C temperature increase in South Africa. Using a robust dataset of 38,742 dryland maize yield observations from 1986 to 2018 at 92 trial locations across South Africa, we employ a fixed effects modeling approach to estimate the change in yield. Results suggest that a 1°C increase is associated with a 7.86% decrease in maize yield, and a 2°C increase is associated with a 17.31% decrease. The robustness of these results reinforces the necessity for focused policy and research on climate change alleviation in agriculture. 2026 Annual Meeting, July 26 - 28, 2026, Kansas City, Missouri