Climate change is testing the sustainability of UK wheat yields

Over the past 30 years, UK wheat yields have largely been resilient to changing weather. However, the future safety of our most common food crops remains uncertain due to increasingly frequent extreme wet and dry conditions as a result of climate change, scientists say.

A research team from the University of Oxford, the UK Center for Ecology and Hydrology (UKCEH), the Met Office and the University of Bristol conducted an in-depth analysis of wheat yields and concurrent meteorological conditions in the country’s main agricultural areas since 1990. They also researched potential effect predicted climate change for production in the coming decades.

The study found that there is significant resilience to a single extreme in the UK the weather events such as low or high rainfall or temperature, thanks to farmers’ effective crop management and wheat’s ability to tolerate different climates.

But the researchers also noticed that some combinations of extreme weather conditions occurred during the growing season and had a significant negative impact on production. For example, in 2020, autumn torrential rains prevented the sowing of crops, only a dry spring affected plant growth and finally, heavy downpours in August created very difficult harvesting conditions, resulting in the lowest UK wheat yields in decades.

UKCEH’s Professor Richard Powell, co-author of the study, says: “Until now, farmers have largely been able to compensate for adverse weather conditions by changing the timing of sowing or harvesting, or by changing the timing and amount of fungicides, pesticides or fertilizers they apply to their fields .

“However, climate change will push the limits of what can be achieved through crop management and it may become increasingly difficult for farmers to cope with the impact of more frequent extreme weather events. This could affect the quality and quantity of crops and therefore food production in the UK.’

The researchers used state-of-the-art high-resolution climate projections up to 2080 to assess how likely future changes in temperature and rainfall under a high-emissions scenario could affect key crop growth stages in the main wheat-producing regions of eastern and southern Britain.

They found that much warmer winter temperatures could offset the negative effects of increased rainfall between October and April, while warmer temperatures and drier conditions in June and July would be generally beneficial to crops.

Dr Louise Slater from Oxford University’s School of Geography and Environment, who led the study, explains: ‘Our research shows that on average higher temperatures are likely to have an overall positive impact on yields in key UK wheat growing regions. However, there may be several of them extreme weather eventssuch as severe thunderstorms or prolonged drought that occur throughout the year and thus increase uncertainty about future wheat yields.’

UKCEH climatologist Dr Chris Huntingford, co-author of the study, added: “Over the last decade we have already seen an increase in both extreme dry and wet periods, depending on the season, and this pattern is expected to continue even with large reductions in greenhouse gas emissionsclimate change will continue to produce weather conditions beyond those in which our intensive agricultural systems evolved.”

Courtesy of UK Center for Ecology and Hydrology