Climate change will reduce nutritional quality of staple crops

Climate-change impacts on food security will involve negative impacts on crop yields, and potentially on the nutritional quality of staple crops like the common bean, which is the most important grain legume staple crop for human diets and nutrition worldwide.

A study conducted by scientists at the National University of Ireland Galway (NUI Galway) in collaboration with the CGIAR Research Programme on Climate Change, Agriculture and Food Security (CCAFS) indicates that both the nutritional quality and the yields of the common bean will be reduced under the climate change-induced drought stresses that will occur in south-eastern Africa by 2050. The study was published in the journal Scientific Reports.

The scientists conducted crop modelling, combined with field trials and molecular lab experiments, to analyse the yields and the nutritional quality of the crop. The crop modelling analysis revealed that the majority of current common-bean growing areas in south-eastern Africa will become unsuitable for bean cultivation by the year 2050. They further demonstrated reductions in yields of available common-bean varieties in field trial experiments at a climate analogue site, representative of future predicted drought conditions.

The nutritional analysis of the different common-bean varieties, grown under the level of drought stress expected under climate change scenarios, revealed that important micronutrients for human health (e.g. iron) were reduced in all of the varieties, while antinutritional compounds such as phytic acid and lead were increased.

The NUI Galway research, funded by Irish Aid, Science Foundation Ireland (SFI) and CCAFS, indicates that under climate-change-induced drought scenarios, future bean servings by 2050 will likely have lower nutritional quality, posing challenges for ongoing climate-proofing of bean production for yields, nutritional quality, human health, and food security.

Climate change may have a severe nutritional impact on many crops worldwide

Lead scientist for the study, Prof Charles Spillane (Director of the Ryan Institute at NUI Galway) said of the research, “Our research, and recent research by other groups, are generating an emerging body of evidence that climate change will reduce the nutritional quality of many of the world’s staple crops due to the effects of rising temperatures, reduced rainfall and rising CO2 levels on the nutritional composition of the crop-derived foods that underpin global food security and human health”.

As it would take decades to develop and disseminate new crop varieties, major investment was needed now to climate-proof the world’s crops and cropping systems so that both their yields and nutritional quality could be resilient to future climate change stresses, the scientist warned.

“Our results highlight the need for accelerated development and seed-system dissemination of heat- and drought-tolerant common-bean varieties that can maintain yields while also improving nutritional quality (e.g. via biofortification breeding) under future climate-change scenarios.”

The research was conducted between Malawi and Ireland as a collaboration between NUI Galway, CCAFS and the International Center for Tropical Agriculture (CIAT). NUI Galway is one of the 13 strategic research partners for CCAFS.

(NUI Galway/wi)

Reference:

Hummel M, Hallahan B, Brychkova G, Ramirez-Villegas J, Guwela V, Chataika B, Curley E, McKeown P, Morrison L, Talsma E, Beebe S, Jarvis A, Chirwa R, Spillane C. 2018. Decline in nutritional quality of common bean under climate change induced drought stress in Africa. Scientific Reports 8: 16187. https://doi.org/10.1038/s41598-018-33952-4