February 15, 2016

Climate scientists warn rising temperatures will affect crop yield, threaten global food security

Despite record-high yields of corn and soybean across the United States in 2014, climate scientists warn that rising temperatures and future extreme weather soon may put in danger crop yields such as those recently experienced.

Steve Long, University of Illinois crop sciences professor and a team of colleagues reported in the journal BioScience that by midcentury, temperatures in Illinois likely will be closer to those experienced today in the mid-South with precipitation amounts ranging between those in East Texas and the Carolinas.

These predictions will mean reduced productivity for Midwest farmers and, consequently, threats to global food security.

"I would argue that this could be the greatest problem that humanity is facing over the next 35 years because we've had a long period of food surpluses. If we go into a period of shortages, that will be hugely disruptive," Long said.

In response to these challenges, the team urges increased spending on agricultural research in the Midwest.

Long and colleagues call for the creation of an integrated network of field research sites across the Midwest from which data on the performance of current and future crops and cropping systems, as well as on-farm management practices could be gathered. Current data provide a very limited understanding of the impacts from factors such as future weather, carbon dioxide and ozone, biotic stressors on crop production, socioeconomic factors and sustainability outcomes.

Because the Midwest already has extensive infrastructure and is a major producer of crops grown around the world, the team believes the Midwest is an ideal location to investigate climate mitigation and adaptation strategies.

An example of a pre-existing facility cited in the article is the joint university and U.S. Department of Agriculture-Agricultural Research Service Soybean Free Air Concentration Enrichment project at the University of Illinois. The facility was designed to monitor the effects of atmospheric change on Midwestern crops as well as to find ways to better adapt crops in the future.

"We've had a lot of surprises and learned a lot of new things ... but this is just one location," Long said. "We don't know that what we've learned in Champaign is going to apply in the southern Corn Belt, Minnesota or the irrigated areas of the western Corn Belt."

Invasive parsnip

Parsnips are native to Eurasia and have been cultivated as a food crop globally for more than five centuries, but wild parsnip is considered a globally invasive weed crowding out native species and producing a sap that can trigger painful rashes.

A new study featured in the journal Invasive Plant Science and Management indicates that invasive wild parsnip (pastinaca sativa) is genetically a lot closer to its vegetable cousin than previously thought.Working toward more effective management strategies, a team from the University of Illinois set out to determine whether invasive wild parsnip originated from escaped parsnip crops or from the accidental introduction of a wild subspecies from Eurasia as a consequence of international travel and trade.

Researchers collected and analyzed genetic markers from wild parsnip growing in its native range in Europe and did the same with wild parsnip in regions of North America and New Zealand where it is considered invasive.

The data showed that the plants are not genetically distinct. Instead, both shared the same genetic variants, and "with no genetic differentiation, it is difficult to determine with certainty whether wild parsnips escaped cultivation or whether they were recently bred from wild strains," said Tania Jogesh, lead author of the study and now a postdoctoral researcher at the Chicago Botanical Garden.

One possible clue, though, is the high level of genetic diversity researchers found within the wild parsnip plants in each region studied. Scientists say this diversity might be attributable to multiple introductions of seeds that were accidentally transported over long distances by humans.

Compiled by Herald-Whig Staff Writer Deborah Gertz Husar.

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