Increasing soil organic carbon helps protect key food crops, like maize and soybeans, from yield losses caused by rising global temperatures, according to research at The University of Western Australia.

The study co-authored by Hackett Professor Kadambot Siddique, from UWA’s Institute of Agriculture, and researchers from Chinese Universities, University of the New South Wales, Wagga Agricultural Institute and University of Tasmania was published in the European Journal of Agronomy.

The study investigated how soil properties influence crop yield responses to increased growing season temperatures. 

Researchers combined data from nine global crop models and 37 climate projections, covering various future climate scenarios, to understand the effects worldwide. 

The results show that soil properties explain more than half of the differences in how maize and soybean yields respond to temperature changes.  

Soil organic carbon was found to be the most influential factor — it improved soil health by increasing moisture retention and nutrient availability and supported crop resilience under heat stress.

In dryland areas especially, higher soil organic carbon levels were linked to reduced yield losses under climate stress, highlighting the potential of soil management in vulnerable agricultural regions.

The study also found soil organic carbon improvements were more effective under moderate warming scenarios and when combined with newer, climate-resilient crop varieties.

“This research provides critical evidence that soil quality, particularly organic carbon, is key to building resilient, climate-smart farming systems”, Professor Siddique said.

“By quantifying these benefits at a global scale, the findings provide a practical, soil-based solution to strengthen sustainable global food production under climate change.”