Findings published in Nature Climate Change by Senthold Asseng, professor of agricultural and biological engineering at the University of Florida, and a global team of scientists, showed global wheat production would fall 6% for every 1°C increase in global temperatures – a drop that represents one-fourth of wheat traded globally.
Speaking to Milling & Grains, Asseng said the sense of urgency was understood by farmers worldwide but this research unveiled the scale of the problem and the need for prompt action.
“Breeders in private and public companies have started to consider improving heat-tolerance in their breeding programs. However, a normal crop breeding cycle is 10-12 years and it will take a while until we will see significant improved heat tolerance added to main varieties,” he said.
In the study, the researchers said ensemble crop modeling would be an important exploratory tool in breeding for identified genetic targets, such as better heat tolerance, extended grain filling and delayed maturity.
Asseng said that in addition to breeding programs, farmers could also work on improved crop management techniques.
“Crop management will include sowing earlier if possible, often restricted by unsuitable soil water and temperature conditions or the harvest of the previous crop, to grow a crop during the cooler part of the year,” he said.
The strength of prediction
The research was conducted with a team of 50 scientists from 15 countries across the world, collating data using an ensemble of computer models against field experimental data.
“We showed that the ensemble median of many models is a better predictor than any single model… By using a model ensemble, we could significantly improve the quality of our simulations and the understanding of temperature impacts on wheat,” Asseng explained.
The researchers said findings indicated wheat losses would likely happen for most regions in the world.
“By extensively ground-truthing models with field measurements and significantly reducing model uncertainty by using model ensemble medians, we demonstrate that wheat yield declines in response to temperature impacts only are likely to be larger than previously thought and should be expected earlier, starting even with small increases in temperature,” they wrote.
Source: Nature Climate Change
Published online ahead of print, doi: 10.1038/NCLIMATE2470
“Rising temperatures reduce global wheat production”
Authors: S. Assent et al.