Kansas agricultural researchers help crops adapt to a hotter, drier world

Hot, dry summers are becoming increasingly common in Kansas, which could take a toll on the state’s farmers.

“Kansas is always in drought, with some intermittent rain,” said Dr. Jonathan Aguilar, an associate professor of biological and agricultural engineering and a Research and Extension specialist at Kansas State University.

Hot and dry conditions can damage key Kansas crops, cutting into farmers’ already narrow profit margins or forcing them to rely on crop insurance to make up for lost income.

Kansas scientists are leading the way in helping agriculture in the state adapt to a hotter, drier world. Some of their approaches include developing new varieties of common crops, improving new crops for widespread adoption, and harnessing the power of soil microbes.

Breeding for heat tolerance

One approach is to teach an old crop some new tricks.

A team of scientists at K-State and University of Missouri is working to breed new varieties of soybean that are better adapted to hot summers. Soybean is one of Kansas’s top crops, making up more than a quarter of the state’s crop value.

However, hot summer temperatures can damage soybeans, resulting in lower yields, and profits, for farmers.

To breed a better soybean, the researchers are looking to the natural genetic diversity of the plant.

Though there are thousands of soybean varieties identified and stored in the US Department of Agriculture’s seed bank, farmers mostly grow a few varieties. The full diversity of soybeans is still a relatively untapped resource.

The researchers plan to identify soybean varieties that are naturally more heat-tolerant. These plants will serve as the basis for their breeding program.

“First we want to identify the proper parents,” said Dr. Bill Schapaugh, a soybean breeder and professor of agronomy at K-State who is one of the project’s lead researchers.

To do this, they’re growing hundreds of different varieties of soybean inside of heated tents. They’ll determine which plants handle heat the best by measuring their yield and seed quality. Then, they’ll look for traits, and the genes encoding them, that are common in the best-performing soybean varieties.

“We’re hopeful that we’ll be able to identify new genes … that’ll help improve heat tolerance,” Schapaugh said.

To introduce the newly-identified genes into commercial soybeans, the researchers will breed the high-performing plants together to create hybrid soybeans. They’ll measure how well the hybrids handle heat stress, and repeat the process for several generations, until they’re happy with the resulting plants.

Schapaugh says that plant breeding is a “methodical process,” so it will likely take a few years before their heat-adapted soybeans are available for farmers.

“You’ve got to start somewhere,” he said. “This is really the first, largest-scale evaluation of heat tolerance.”

Diversifying Kansas crops

Other teams are focusing on diversifying the crops grown in Kansas, in hopes that new crops may be better suited for hot, dry conditions.

“We want to make sure that we provide farmers options,” said Dr. Ignacio Ciampitti, a cropping systems specialist and associate professor at K-State.

One candidate is sorghum, a grain originally from Africa that can be used for animal feed, biofuels and even human consumption. Sorghum can be used to make a syrup similar to corn syrup and is often found in the gluten-free, ancient grain mixes available at grocery stores. Sorghum is an incredibly efficient crop, delivering higher yields on less water than thirstier crops like corn.

Kansas currently leads the nation in sorghum production. Sorghum is particularly popular in central and western Kansas, which tend to be drier than the eastern part of the state.

Researchers at the K-State Center for Sorghum Improvement, including Ciampitti, are working to further increase the crop’s foothold in the state through a collaboration with the Foundation for Food and Agriculture Research and Corteva Agriscience, which is based in Wilmington, Delaware.

Their goal is to develop new sorghum varieties that produce even more high-quality grain while using less water. They’re also developing sorghum that can tolerate different environmental conditions, giving farmers more options for incorporating sorghum into their existing crop rotations.

The scientists are using a plant breeding approach similar to the soybean researchers. They’re also making use of crop models, computer programs which can predict how their new sorghum varieties will perform in different environments.

The public-private collaboration is key for the scientists to quickly bring improved sorghum varieties to market. Because of Corteva’s involvement, Ciampitti hopes that any advances can be “immediately translated into something that can reach farmers.”

Going underground

Another aspect of drought resilience has to do with the microbes that live on plants, which are collectively referred to as the plant microbiome.

Just like humans, plants play host to millions of microbes on their surfaces and inside their bodies. Some microbes are harmful, but many seem to actually help plants.

“We know about a lot of microbes that can improve growth, they can help plants acquire nutrients and water,” said Dr. Maggie Wagner, an assistant professor at the University of Kansas and an assistant scientist with the Kansas Biological Survey. Wagner recently obtained funding from the National Science Foundation to investigate how soil microbes can help plants adapt to drought.

Other researchers have found that the microbiome plays a key role in helping crops survive drought conditions. But so far, scientists know very little about how, and why, microbes help plants become more drought-tolerant.

“One of the things I’m very interested in is trying to understand why these plants and microbes evolved to interact with each other in this way,” said Wagner.

To find out, Wagner and her team will subject microbes to simulated droughts in the laboratory. First, they’ll identify which microbes are best equipped to handle dry conditions. Then, they’ll introduce those microbes to plants in a greenhouse to see how they affect plants experiencing drought.

The team will also study one of the best natural drought experiments out there — Kansas.

“Any Kansan who’s driven across the state will be familiar with this, where as you go from east to west, you get fewer and fewer trees and drier and drier weather,” Wagner said. “That provides a really nice natural experiment.”

Wagner’s team will use high-tech genetic sequencing methods to determine the identities and functions of microbes in increasingly dry soils across the state. Their findings will shed light on which microbes might help their plant hosts adapt to drought.

The scientists’ findings could be used to inform new farming practices to support beneficial relationships between microbes and plants. Their results may also accelerate the development of commercial technologies, like seed coatings loaded with microbes that can help plants grow in drier conditions.

“There is an art and there is a science on dealing with drought,” said Aguilar, the extension specialist.

As Kansas researchers continue to advance the science of drought adaptation, hopefully farmers will be better equipped to handle the art.

This story was originally published August 24, 2020 at 5:01 AM.