Clemson research dollars support breakthroughs in water conservation, crop production

CLEMSON — Research dollars awarded to Clemson University scientists are helping fuel the discovery of new and efficient ways to grow food and conserve the state’s natural resources.

Scientists in the College of Agriculture, Forestry and Life Sciences and the university’s Public Service and Agriculture division were awarded more than $17 million in research grants during the 2018 fiscal year from an array of state and federal agencies, including the U.S. Department of Agriculture and several South Carolina commodity boards.

“The amount of funding our scientists have secured is a testament to the quality of the research we are conducting in the agricultural and natural resources areas,” said Paula Agudelo, interim associate dean of research for CAFLS. “Scientists in CAFLS are conducting research that has a direct impact on the prosperity of South Carolinians. Our research supports our agribusiness industry and helps tackle looming concerns about food security and natural resources sustainability.”

Conserving irrigation water

Water is among the most vital natural resources for the state, both in terms of resource management and the future of agriculture. CAFLS assistant professor of horticulture Sarah White was the recipient of a grant in excess of $2.4 million to evaluate, along with a national team of researchers, “Clean WateR3 – Reduce, Remediate, Recycle: Informed Decision-Making to Facilitate Use of Alternative Water Resources and Promote Sustainable Specialty Crop Production.”

The project director for the grant, White is an 80 percent recipient, while Dan Hitchcock, associate professor at Clemson University’s Baruch Institute of Coastal Ecology and Forest Science in Georgetown, is a 20 percent recipient at more than $600,000.

Clean WateR3 is a federally funded Specialty Crops Research Initiative grant focused on research and outreach to help growers reduce, remediate and recycle irrigation water. Its projects focus on developing sustainable remediation technologies to encourage use of alternative water resources, especially recycled irrigation runoff, to decrease dependence on potable water and enhance long-term economic viability.

White was honored in January with the Southern Nursery Association Environmental Leadership Award, which recognizes individuals and businesses that have demonstrated exceptional leadership and through their voluntary efforts exemplified inspiration, vision, innovation, leadership and action to preserve and protect the environment.

“My focus is on water; how we can protect it, use it more wisely and clean it once it has been used,” White said.

Monitoring the state’s rivers and streams

While White and Hitchcock are working to protect the state’s water resources by focusing on irrigation water, another CAFLS scientist, freshwater ecologist Cathy Jachowski, is helping monitor diminishing water quality in South Carolina’s rivers and streams.

Through a National Fish and Wildlife Foundation grant, Jachowski is working to identify habitat requirements to inform restoration and species recovery for the Carolina heelsplitter — the only federally endangered mussel species in South Carolina — that lives in rivers and streams in South Carolina and a small portion of North Carolina.

While the work is ostensibly for the purpose of restoring the population of heelsplitters, freshwater mussels are broadly viewed as a reliable indicator species of environmental change, and scientists consider the heelsplitter particularly sensitive to shifts in water quality. Thus, when populations aren’t thriving or reproducing, it serves as a harbinger of diminishing water quality for South Carolina’s rivers and streams.

“Most people have probably never heard of a heelsplitter; probably most people will never see one in their entire lives,” Jachowski said. “But we think of our rivers and streams of South Carolina as really valuable resources, and with this project the heelsplitter is kind of the tool or the means we’re using to learn more about the condition of those resources.”

Making forests grow

On the state’s coastal plain, Clemson University scientist Thomas O’Halloran is using an atmospheric measuring technique and statistical method called eddy covariance, or eddy flux, to determine exchange rates of trace gases over natural ecosystems — in this case, the longleaf pine forest at the Baruch Institute.

With instruments mounted on a 120-foot tower to measure the amount of carbon dioxide the pine trees are absorbing from the atmosphere and by studying the data over an extended time period, O’Halloran can develop statistical relationships between the variables that affect the trees’ growth.

“What that means is it helps you to develop tools to understand what makes forests grow, and that’s useful for foresters who want to know what makes trees grow and how to make them grow better,” he said.

And making trees grow better is good news for South Carolina’s forestry industry.

A 2017 analysis by Clemson professors measured the contribution of the forestry sector to the state’s economy at more than $21 billion and 84,000 jobs, making it South Carolina’s No. 1 manufacturing sector in terms of jobs and labor income ($4.5 billion).

“Understanding the role of forests in South Carolina’s Lowcountry landscape ecology is a priority of the Baruch Institute as we seek to provide scientific data to help manage the Lowcountry sustainably,” Baruch director Skip Van Bloem said.

Cutting production costs

Grant-funded research being conducted at Clemson’s Edisto Research and Education Center is geared toward helping farmers save in production costs while benefiting from high yields. In a study funded by the South Carolina Cotton Board, agriculture engineer Kendall Kirk is studying in-field variability on cotton yields. The goal is to help more cotton seeds develop into profitable crops by understanding what factors are related to producing high-quality, high-yielding crops.

“In this study, we’re looking at cotton yields as related to factors such as disease ratings, insect ratings, thrips ratings and so on,” said Kirk, who is stationed at the Edisto Research and Education Center. “This study will help to better understand factors affecting gin turnout and fiber quality, as well as help improve guidelines for identifying management zones in cotton fields.”

Factors Kirk will look at include soil texture, soil electrical conductivity, soil organic matter content, canopy temperature, soil moisture content, rate of canopy closure, weed pressure, standard soil nutrient tests, nematode counts, picking losses, plant tissue analysis and maturity measurements.

Other research conducted at the Edisto REC includes work by Clemson doctoral student Phillip Williams to develop and test a sensor-based, variable-rate nitrogen applicator for use with center-pivot irrigation systems in cotton fields. Williams received a grant from the USDA-National Institute of Food and Agriculture for this study in which he plants a “nitrogen-rich” strip of cotton and flies a drone over it to collect information related to nutrient content. He then uses a global positioning system to map the field’s nutrient deficiencies. That information, along with planting date and historical yield data, is used to determine how much fertilizer needs to be applied and where. A variable-rate applicator connected to an irrigation system then applies only the amount of fertilizer needed at variable rates throughout the field.

In an on-farm trial, Williams demonstrated savings of up to $54 per acre. Using the technology, Williams reduced fertilizer applications by nearly two-thirds over the conventional rule-of-the-thumb applications of 90 pounds of nitrogen per acre. For more information, visit www.clemsonnitrogencalculator.com.

Optimizing seeding rates

Another grant-funded program Kirk is involved with is developing a system he calls “Directed Rx” or “Directed Prescriptions.” This method is used for prescribing variable seeding rates that would help farmers optimize spatial assignment of rates. Supporters for this project are Cotton Inc., the South Carolina Soybean Board and Monsanto Company.

With the help of postdoctoral associate Wei-zhen Liang and a grant from the South Carolina Soybean Board, Kirk’s group also is developing image analysis software to quantify soybean leaf defoliation. Farmers typically use a visual estimate to determine if insect damage has reached a level that requires treatment. That defoliation is often over-estimated, however, and farmers spend money on unneeded insecticide treatments, Kirk said. Kirk and Liang are developing a website where farmers could upload leaf or canopy images and receive a spray recommendation.

Conserving water on the farm

Joe Maja, a research sensor engineer at the Edisto REC, received a grant from the Clemson University Research Foundation to refine a fully programmable irrigation system that disperses water at three predefined thresholds, controls the irrigation valve and turns off irrigation remotely. The Clemson aWater (automatic water) System is a sensor-based control system that provides real-time data visualization at 15-second intervals. This technology will prove especially useful for agriculture in water-scarce areas.

New soybean cultivar extends growing season

The soybean planting season and growing region have been extended thanks to researchers at Clemson University’s Pee Dee Research and Education Center.

The Agustina soybean cultivar was developed and released by soybean breeders Benjamin Fallen and Emerson Shipe. Fallen said this cultivar possesses the long juvenile (LJ) trait, which gives it the ability to produce high yields even when days get shorter and daylight hours are fewer. The LJ trait also allows the Agustina soybean to be grown in regions not suited for most existing soybean cultivars.

“The United States and Brazil are the largest soybean producers,” Fallen said. “Most of the time, when a new soybean cultivar is developed, it is adapted for specific regions in these countries.”

Most soybeans grown in Brazil are found in areas from latitude 10 degrees south to 25 degrees south, or from Mato Grosso to Parana. Most soybean varieties in the U.S. grow in areas between latitudes 35 and 45 degrees north, or from Arkansas to Minnesota. Fallen said Agustina is more adapted and performs best in regions from latitudes 22 to 29 degrees north, which means this line offers a much-needed resource for this region.

“Agricultural and environmental research is central to our mission as a land-grant university, and I commend our many scientists with PSA and CAFLS for working closely with stakeholders in communities throughout the state to pursue research that will improve the quality of life in South Carolina,” said Tanju Karanfil, vice president for research.