Agriculture is seen as both a key cause of the global biodiversity crisis and a principal means of addressing it. Some are calling for farmers to return to heirloom varieties as a way to address the growing challenges posed by climate change. But new research from the University of Minnesota suggests the solution lies primarily in modern scientifically-bred crop varieties. They’ve led to an increase in biodiverse cropping practices and significantly greater wheat yields.
Researchers from the University of Minnesota-Genetics Environment Management Socio-Economic Informatics Center, Department of Applied Economics and the Minnesota Supercomputing Institute assembled area data and associated genetic pedigrees for 1,353 commercial wheat varieties that composed most of the U.S. crop from 1919 to 2019. They factored in phylogenetic breadth when estimating both the spatial and temporal diversity of commercial wheat varieties found in fields. And they tracked how that breadth changed through time across the country.
“Many perceive that science has led to cropping systems that are less biodiverse,” said Philip Pardey, a professor of applied economics. "We set out to see if that was the case using newly developed, long-run data for a scientifically intensive cropping landscape.”
The increasingly intensive use of scientifically-selected crop varieties has led to more, not less, biodiverse cropping practices, at least regarding diversity in the U.S. wheat crop, the researchers found. They also found that a substantial increase in varietal diversity in the past century has been achieved in tandem with a fourfold increase in U.S. average wheat yields.
People are also reading…
“The increasing number of locally adapted varieties and faster turnover of newer varieties grown by wheat farmers demonstrated a success story of modern agriculture achieved by farmers and breeders,” said Yuan Chai, a researcher at the informatics center and lead author of the study.
“The push for farmers en masse to return to heirloom varieties or landraces isn’t a sustainable solution,” said Kevin Silverstein, scientific lead at the Supercomputing Institute. “Innovation in scientifically bred varieties is enabling us to feed more people on less land, fertilizer and water while improving overall crop diversity.”
Agriculture is being asked to address an increasingly large number of sustainable-development challenges. In addition to the long-standing role of crop productivity improvement to alleviate poverty and improve food security, ever-more sustainable-cropping systems are required to address growing challenges posed by climate change, land and water scarcity, and new pest and disease threats.
But public investment in crop-breeding research is declining in the United States and falls chronically short in many other countries. Building meaningful climate and pest resilience into the world's food crops in ways that also achieve global food security goals requires doubling down on crop-improvement research that enhances, not undermines, crop biodiversity.
Some of the analytic tools developed by the informatics center to examine the research are being further developed to enable other investigations of the changing diversity landscape in other crops and other countries.