Taking a closer look at headwater streams in light of climate change

By John Lovett
University of Arkansas System Division of Agriculture
Arkansas Agricultural Experiment Station 

FAYETTEVILLE, Ark. — Up to 35 percent of headwater streams, which make up the vast majority of global river miles, are intermittent, yet the importance of these systems is not well understood due to the recurring wetting and drying cycles. 

HEADWATERS — Kathleen Cutting takes stream monitoring notes on Brush Creek, a headwater stream of the White River and part of the Beaver Lake watershed. (U of A System Division of Agriculture photo)

Arkansas researcher Shannon Speir is part of a multi-state team working to learn more about how these small streams can affect lakes and reservoirs that supply our drinking water. The research may have implications for guidance on Clean Water Act regulations and monitoring the primary source of drinking water in northwest Arkansas in response to climate change.

Speir is an assistant professor of water quality in the crop, soil and environmental sciences department for the Dale Bumpers College of Agricultural, Food and Life Sciences at the University of Arkansas and the Arkansas Agricultural Experiment Station, the research arm of the University of Arkansas System Division of Agriculture.

With her team of student researchers, they will study the movement of nutrients, such as nitrogen and phosphorus, in Brush Creek, a tributary of the Beaver Lake watershed. It is part of a larger study across many states that is funded by the U.S. Department of Energy to learn more about the impact headwater streams have on major bodies of surface water.

“We are looking at when the tiny streams go dry at the top and then rewet, and dry and rewet, how that affects nutrient transport downstream,” Speir said.

Speir said there is potential for headwaters to be major transporters of nutrients and sediments throughout the year. Intermittent headwater streams tend to flow after heavy rains and carry nutrients downstream. An overabundance of nutrients like nitrogen and phosphorus, Speir said, can cause eutrophication, which increases the amount of plant and algae growth and decreases the amount of available oxygen for fish.

She is teaming up with water quality scientists in five other states to expand the knowledge of how these intermittent stream networks that dry up and fill back up after storms can determine the amount and quality of water that ends up downstream.

“If we can understand how conservation in one part of the watershed might affect the signal downstream, we can start to understand how much conservation we need to make changes downstream,” Speir said. “This grant provides an underlying foundational science backbone supporting more applied work.”

Headwaters researchers

The two-year research project begins this month and is supported by a $2.5 million grant awarded by the Department of Energy through its Established Program to Stimulate Competitive Research, or EPSCoR, program. Speir’s lab will receive about $330,000 to purchase new water quality sensors and conduct research on Brush Creek in the Beaver Lake watershed. She said sensors will be “nested” in public access areas of the creek.

The grant proposal was submitted through the University of New Mexico’s Center for Advancement of Spatial Informatics Research and Education. The award is part of a $33 million Department of Energy effort that supports 14 research projects covering a range of research topics, from fundamental science topics to efforts in fusion energy, climate and ecosystem modeling, grid integration, wind energy, and sensors for energy conversion.

Alex Webster, assistant professor in the University of New Mexico’s biology department, is the principal investigator on the project. Her team in New Mexico will study the headwaters of the Santa Fe River and serve as the hub for project data analyses.

“Historically, we treated these headwater watersheds like black boxes. We tend to care about how much water comes out of them and the quality of that water but not so much about the reasons why,” Webster said in a University of New Mexico news release. “There is a lot going on in them; they are changing very quickly because they are very sensitive to climate change, including to changes in snowpack, and because that’s where streams tend to dry up first.”

Co-principal investigators and research areas include:

• Arial Shogren, University of Alabama biological sciences department; headwaters of the Black Warrior River

• Joanna Blaszczak, University of Nevada, Reno’s natural resources and environmental science department; headwaters of the Truckee River

• Adam Wymore, University of New Hampshire’s college of life sciences and agriculture; headwaters of the Great Bay Estuary

• Yang Hong, University of Oklahoma’s college of engineering; hydrologic modeling

Speir said hydrologic modeling, using computer simulations of watershed reactions, will be the first stage of the study, and this is a specialty of Hong’s team at the University of Oklahoma. The first stage of the study calls for simulating the processes of entire watershed stream networks based on observations of water flow, precipitation, and other factors.

The second stage includes understanding each watershed’s “spatial structure” or how it influences water quality and quantity. The third phase will look at changes over time in response to changing precipitation and drought patterns. Project researchers will also collaborate with the Department of Energy’s Oak Ridge National Laboratory to compare findings to a Tennessee watershed.

With more knowledge of headwater processes, the study could help states better monitor and manage water quality, water quantity, and ecosystem responses to a changing climate, Speir said. For example, it could help water treatment facilities better predict what’s coming into the system and adjust their process accordingly.

Speir’s team on the project includes Kathleen Cutting, a water quality science master’s degree student, and program associate Alana Strauss, both with the crop, soil and environmental sciences department. Her team will conduct “synoptic sampling campaigns,” where they take a snapshot sampling in one day of 20 sites across the watershed.

To learn more about Division of Agriculture research, visit the Arkansas Agricultural Experiment Station website: https://aaes.uada.edu. Follow on Twitter at @ArkAgResearch. To learn more about the Division of Agriculture, visit https://uada.edu/. Follow us on Twitter at @AgInArk. To learn about extension programs in Arkansas, contact your local Cooperative Extension Service agent or visit www.uaex.uada.edu.

Celebrating Arkansas Blackberry Month with research, education

By Sarah Cato
U of A System Division of Agriculture

CLARKSVILLE, Ark. — Gov. Sarah Huckabee Sanders has proclaimed June as Arkansas Blackberry Month and the University of Arkansas System Division of Agriculture celebrated by hosting a field day to showcase its research and education efforts.

A MONTH OF BERRIES — Margaret Worthington, associate professor of horticulture for the U of A System Division of Agriculture, addresses attendees during the blackberry field day in Clarksville earlier in June. (Division of Agriculture photo.)

The 2023 Blackberry Field Day, hosted in partnership with the Arkansas Blackberry Growers Association at the Fruit Research Station, welcomed almost 90 blackberry growers from Arkansas, Missouri, Texas and Oklahoma. The research station is a part of the Arkansas Agricultural Experiment Station, the research arm of the Division of Agriculture.

The Division of Agriculture is world-renowned for its blackberry varieties, which are grown on every continent except Antarctica. In 2017, blackberry production in the U.S. was valued at $31.1 million, according to the Agricultural Marketing Resource Center.

The field day kicked off with indoor presentations on blackberry aromas and efforts to boost public interest in blackberries.

Promotion research

“We’ve partnered with the Arkansas Blackberry Growers Association to increase blackberry promotion in Arkansas,” said Lizzy Herrera, extension horticulture program associate for the Division of Agriculture. “We’ve created several promotional materials in an attempt to market blackberries as the healthy, fresh and local treat we know they are.”

With funding from the Specialty Crop Block Grant, administered by the Arkansas Department of Agriculture, Herrera said a survey was distributed last year to assess marketing habits, pricing, and what type of promotional materials growers would like to see. These answers were used to create recipe cards, stickers, road signs, and other promotional materials. Sales dollars for participating farms will be tracked over two years.

Increasing herbicide options

Matt Bertucci, assistant professor of horticulture for the Division of Agriculture, discussed his research on utilizing 2,4-D choline, a post-emergent broadleaf herbicide, in blackberry production. The chemical is not currently labeled for use in blackberries in Arkansas.

Pre-emergent herbicides, which target germinating seeds, are typically used to control broadleaf weed species. But pre-emergent herbicides can fail over time and are not effective on perennial broadleaf weed species.

“You may be wondering why we’d spray a broadleaf herbicide on a broadleaf crop,” Bertucci said. “Our goal is to apply enough chemical to kill the weed, but not enough to hurt our plants.”

Bertucci’s research aims to pin down that sweet spot of how much herbicide will effectively control broadleaf weed populations without lowering yield or fruit quality, and, hopefully, get the product labeled for use in Arkansas blackberries to give growers more options to control problematic broadleaf weed species. This research is funded by the IR-4 Project, an organization with a focus on developing data required by the U.S. Environmental Protection Agency for the registration of pest management tools for specialty crops.

Rotating Cross Arm Trellis

Amanda McWhirt, horticulture production specialist for the Division of Agriculture showed attendees the rotating cross arm trellis, or RCA, used in her current research trial looking at labor data, fruit quality, and canopy conditions compared to the traditional T-trellis. However, one major benefit to the RCA comes with the recent surge in early season freezes Arkansas fruit growers have suffered the past few years.

“We’ve had many growers implement the RCA on their operation with great success,” McWhirt said. “It creates a really attractive wall of blackberries that is great for U-Pick operations, and several have said it’s saved them from the freezes we’ve been dealing with the past several years.”

The RCA trellis allows growers to lay the plants down, closer to the ground. This, paired with a cover, keeps the buds warmer during early-season cold snaps, oftentimes saving them from significant cold damage. However, the RCA helps battle summer struggles as well.

With the RCA, plants produce fruit on one side of the trellis. During the summer, producers can rotate the trellis to keep the fruit in the shade and reduce sun exposure, which McWhirt said is a common cause of red drupe, white drupe, and sunscald. This practice also reduces temperature and lowers humidity within the canopy, making a less-favorable environment for spotted wing drosophila, a common pest of blackberries. But the environmental characteristics aren’t the only advantage when it comes to controlling spotted wing drosophila on an RCA.

“We have also seen increased coverage in our insecticide sprays targeting spotted wing on the RCA. It gives us a nice wall of berries and your sprayer will hit them dead on every time,” said Aaron Cato, horticulture IPM specialist for the Division of Agriculture. “Because of this, we think it is possible that the RCA requires less spray volume compared to our traditional T-trellis. It may not seem like much, but if you’re covering a ton of acres, reducing 10 to 20 gallons of water can save a lot of time.”

Cato said other cultural control options are a must as well. He suggests harvesting often, keeping fields clear of discarded or culled berries and moving harvested fruit into cold storage as soon as possible.

The field day had an extended tour that touched on the blackberry breeding program, summer tipping reminders, blackberry fertility, and more. Learn more about blackberry production in Arkansas at uaex.uada.edu.

To learn about extension programs in Arkansas, contact your local Cooperative Extension Service agent or visit www.uaex.uada.edu. Follow us on Twitter and Instagram at @AR_Extension. To learn more about Division of Agriculture research, visit the Arkansas Agricultural Experiment Station website: https://aaes.uada.edu/. Follow on Twitter at @ArkAgResearch. To learn more about the Division of Agriculture, visit https://uada.edu/. Follow us on Twitter at @AgInArk.

Soybean breeder Caio Canella Vieira joins Arkansas Agricultural Experiment Station

By John Lovett
University of Arkansas System Division of Agriculture
Arkansas Agricultural Experiment Station

FAYETTEVILLE, Ark. — Soybean breeder Caio Canella Vieira is building a bridge from the past to the future at the Arkansas Agricultural Experiment Station.

SOYBEAN BRIDGE  — Caio Canella Vieira joined the Arkansas Agricultural Experiment Station as a soybean breeder in January. (U of A System Division of Agriculture photo by Fred Miller)

Vieira plans to use advanced genetic tools to speed up the development of new varieties with improvements like yield potential, adaptability in broad environments, and overall resilience to biotic and abiotic stressors.

In January, he joined the experiment station and now occupies the office once used by his former mentor and advisor, the late Pengyin Chen. As an assistant professor in the crop, soil and environmental sciences department, Vieira will also teach plant breeding through the Dale Bumpers College of Agricultural, Food and Life Sciences at the University of Arkansas.

“Arkansas has an incredible legacy of developing varieties, and has a very well-known program,” Vieira said. “We now have an opportunity to take this traditional program into a highly data-driven program maximizing genetic gain. If you can shorten the time to identify superior lines, you can likely improve genetic gain in a breeding cycle.”

He said the time it would traditionally take to develop a new variety, seven to eight years, could be cut in half with modern “predictive breeding” methods using genome-wide molecular markers and advanced statistics. A plant’s genetic information is collected earlier in the breeding cycle, then used to predict a trait of interest before reaching field trials.

“The genetic base of modern soybean is extremely narrow,” Vieira said. “We have a handful of genetically diverse accessions that are the basis of the genetics in the United States, but we have over 20,000 that could have constituted the genetic basis.”

In plant breeding, a genetically diverse accession is a plant material collected at one time from a specific location across the globe. A panel of genetically diverse accessions attempts to capture the genetic diversity available for a given species for further usage in breeding and genetic studies.

“There is a lot of genetic diversity lost during domestication and intensive breeding. I hope we can find economically important traits lost during domestication and breed them back in,” Vieira said.

To make it happen, Vieira combines intuition with data analytics. He collaborates with experts in other areas of plant science like physiology and pathology, along with statisticians and quantitative geneticists. Collaborations are a key element of his work.

“There’s only so much you can do by yourself, especially with breeding where you need a lot of data, which often have substantial interactions with the environment. The more collaborative you get, the better your projects are going to be,” Vieira said.

“Dr. Vieira brings experience, vision, and energy for soybean breeding, and I am confident he is going to take our program to new heights,” said Jeff Edwards, head of the crop, soil and environmental sciences department. “Soybean breeding is one of our largest research programs, and we are fortunate to attract someone with Dr. Vieira’s potential for our next generation of leadership and scientific innovation.”

Edwards said Vieira is “a great communicator and a great listener” who is eager to interact with Arkansas soybean producers and learn about their needs.

“I don’t think there is any doubt that his program will deliver genetics that reflect the needs of the Arkansas farmer,” Edwards added.

Soybeans are Arkansas’ top cash crop, worth more than $1.9 billion and planted on over 3 million acres in the state, according to the 2022 Arkansas Agriculture Profile. Vieira has already worked on projects that address many of the issues faced by Arkansas soybean farmers, from disease and pest resistance to broad environmental adaptation and base economic factors of improved yield and oil content. He also participated in a study with Chen to identify soybean varieties tolerant of off-target dicamba herbicide.

While improvements in yield potential and adaptation to environments guide soybean plant breeding goals, Vieira said there are also opportunities to improve consumer qualities in edamame and natto soybean varieties by working with local farmers and scientists from other departments.

Vieira came to the United States in 2014 after finishing the first two years of his undergraduate studies at the University of São Paulo, Brazil, under Baldin Pinheiro’s guidance. He studied for a year at the University of Minnesota and was a visiting scholar at Purdue University under the supervision of Katy Rainey before earning his master’s and a doctorate in plant breeding, genetics, and genomics at the University of Missouri-Columbia, with Chen and Henry Nguyen as his advisors. Vieira received the Monsanto Graduate Student Scholarship in 2018, was named a National Association of Plant Breeders Borlaug Scholar in 2019, and received the Corteva DELTA Scholarship in 2021.

To learn more about Division of Agriculture research, visit the Arkansas Agricultural Experiment Station website: https://aaes.uada.edu. Follow on Twitter at @ArkAgResearch. To learn more about the Division of Agriculture, visit https://uada.edu/. Follow us on Twitter at @AgInArk. To learn about extension programs in Arkansas, contact your local Cooperative Extension Service agent or visit www.uaex.uada.edu.