Save the Bay, save agriculture

By Michael Sutphin, College of Agriculture and Life Sciences

Restoring the Chesapeake Bay to the pristine inlet Captain John Smith encountered 400 years ago, while ensuring the livelihood of those who produce the nation’s food supply, is more than a wish or a hope; it is a professional commitment.

In 2000, the governors of Pennsylvania, Maryland, and Virginia; the mayor of the District of Columbia; the chairman of the Chesapeake Bay Commission; and the administrator of the U.S. Environmental Protection Agency signed an agreement to protect the living resources of the Chesapeake Bay and its tributaries, preserve the natural habitats within the bay, and achieve the water quality needed to support these habitats. They committed to reduce the annual intake of nitrogen that enters the bay by 110 million pounds within a decade. With only two years remaining to meet this deadline, the Chesapeake Bay Foundation — the largest regional conservation organization in the United States — reports in its 2007 “State of the Bay” scorecard an estimated 19 million pound reduction, only 17.5 percent of the Chesapeake 2000 Agreement’s goal.

Scientists from nonprofit groups, colleges and universities, and government agencies have been working to improve these figures with limited funding and other resources. Virginia Tech researchers are leading many of the efforts in Virginia to reverse the toll that nonpoint source pollution has taken on the Chesapeake Bay, the country’s largest estuary.

Turning problems into resources

More than 64,000 square miles in New York, Pennsylvania, Delaware, Maryland, West Virginia, and Virginia drain into the Chesapeake Bay. A population boom within recent decades has increased urbanization, while production agriculture has continued to be part of the region’s economy, especially in the Shenandoah Valley. Scientists have identified these factors as part of the bay’s pollution problem.

“The Shenandoah Valley in Virginia is a major part of the Chesapeake Bay Watershed and contributes large amounts of excess nutrients because of the amount of agricultural production in the region,” says Saied Mostaghimi, professor and head of the Department of Biological Systems Engineering at Virginia Tech. He is a member of the Scientific and Technical Advisory Committee (STAC) of the Chesapeake Bay Program, a regional partnership that directs bay restoration efforts. “Over the years, producers in the region have been applying phosphorus and nitrogen to the soil, but now the soil is no longer able to absorb all of the excess nutrients.”

Instead, Mostaghimi says, these nutrients get into streams during storms and may even permeate shallow groundwater and eventually make their way into the bay. Several Virginia Tech researchers are working with producers to change these practices to prevent some pollution from the onset. Katharine Knowlton, associate professor of dairy science, oversees a $1 million grant from the National Fish and Wildlife Foundation (NFWF) that funds a handful of coordinated research projects at Virginia Tech.

“The funding for this research arises from the Waste Solutions Forum (WSF), a grassroots stakeholder group that convened for the first time in April 2005 to address nutrient challenges for animal agriculture, particularly in the Shenandoah Valley,” Knowlton says. Researchers involved in the WSF have received more than $5 million from various government agencies and nonprofit groups for research projects identified at the forum.

One problem is what to do with the litter from poultry houses. Foster Agblevor, associate professor of biological systems engineering, is developing a transportable pyrolysis unit to convert poultry litter into bio-oil, producer gas, and fertilizer. “We are treating the poultry litter as a resource, not a problem,” Agblevor says.

Agblevor hopes his pyrolysis unit can remove 5.8 million pounds of phosphorus and 5 million tons of nitrogen each year from the Shenandoah Valley. This research has applications worldwide. “Once we demonstrate it at the test site in Dayton, Va., we are willing to move it to other areas around the country,” Agblevor adds. “Once it is developed, it can be applied anywhere.”

Jactone Arogo-Ogejo, assistant professor of biological systems engineering and waste management Extension specialist, is applying similar principles to nutrient removal on dairy farms in the valley. He is using a cone-shaped reactor that can be placed on a dairy farm to capture phosphorus in the manure and transform it into struvite, a phosphate-rich crystal. Arogo-Ogejo has already built, installed, and is now testing a pilot-scale cone reactor in Dayton, Va., near Agblevor’s test site.

“I am looking at what operating parameters, such as the pH level in the manure, and what manure pretreatment methods would be most effective to recover struvite,” Arogo-Ogejo explains.

Water quality a top issue

Other researchers are dealing with the excess nutrients and sediment after they have entered the bay and its tributaries. Kurt Stephenson, associate professor of agricultural and applied economics at Virginia Tech, and Bonnie Brown, associate professor of biology at Virginia Commonwealth University, have turned to native oyster aquaculture as a possible means to assimilate excess nutrients already in the bay. They have established field sites in Virginia and Maryland to estimate the amount of nitrogen and phosphorus removed by the oyster biomass harvest and nutrient processing. One goal of this study is to examine the feasibility and cost-effectiveness of incorporating nutrient assimilation credits into state-sponsored nutrient reduction programs.

“Right now there is limited opportunity for oyster aquaculture to expand in the Chesapeake Bay, but if oyster producers could have two sources of revenue, the industry might develop further,” Stephenson says. “These producers are already making money for the first service they provide, the food, but they may need to be paid for the second, the water-quality service, to expand.”

Stephenson is not the only Virginia Tech economist looking at policy changes as a possible solution for excess nutrients in the bay. Jim Pease, professor of agricultural and applied economics and agricultural operations Extension specialist, has been dealing with Chesapeake Bay issues since the early 1990s when he conducted a largescale survey of fertilizer use in Virginia’s Northern Neck and Rockingham regions of the state and found that livestock farmers were overusing phosphorus-rich manure on their lands by 64 pounds per acre. Since then, Pease has demonstrated that many farmers would not lose money by improving water quality, because they would be using costly nitrogen more effectively.

“It is a win-win situation for farmers with both positive environmental effects and positive economic benefits,” says Pease, who is also a member of the Chesapeake Bay Foundation’s STAC.

With the help of Darrell Bosch, professor of agricultural and applied economics, and graduate student Todd Metcalfe, Pease conducted research a couple of years ago on a best management practice (BMP) to ensure the revenue of farmers who reduce their nitrogen fertilizer levels by 15 percent. “The Virginia Department of Conservation and Recreation is considering adopting this BMP for nutrient trading credits,” Pease adds.

Brian Benham, associate professor of biological systems engineering and director of the Center for Watershed Studies at Virginia Tech, is also dealing with water-quality issues. He leads studies related to developing total maximum daily loads (TMDLs) for watersheds throughout Virginia, especially within the Chesapeake Bay Watershed. A TMDL determines the amount of a specific pollutant that a body of water can assimilate without violating government water-quality standards. Under the Clean Water Act, TMDLs are required for those bodies of water that violate these standards.

“The center is also involved in developing watershed management plans for watersheds where TMDLs have already been developed,” says Benham, who is also a water-quality Extension specialist. “These plans provide guidance for stakeholders about implementing the pollutant load reductions specified in a TMDL. The work we do will result in water-quality improvements in the TMDL watersheds and downstream in the bay.”

The center conducted a TMDL on Stroubles Creek, a small headwater stream in Blacksburg, Va., that has proved to have important applications for the bay even though it is not within the Chesapeake Bay Watershed. Theresa “Tess” Wynn, assistant professor of biological systems engineering, and W. Cully Hession, associate professor in the same department, are using Stroubles Creek to study common approaches to stream restoration, a $1 billion per year business in the United States.

Using a two-year grant from the Virginia Department of Conservation and Recreation (DCR), Wynn and her colleagues have split a 1.3-mile section of the stream’s main channel and a tributary into three sections to study sediment levels after livestock have been removed, the effect of woody vegetation on the stream bank, and form-based channel design. The stream now serves as an outdoor laboratory for researchers wanting to know the best ways to improve streams, whether they empty into the New River or a tributary of the bay. Small headwater streams, such as Stroubles Creek, are important because they account for nearly 80 percent of the total stream length within the average watershed.

A sustainable agricultural industry

Virginia Tech researchers hope these efforts will help restore the bay and aid the agricultural industry. “Not only are we trying to protect the water quality in the Chesapeake Bay Watershed, but we’re also trying to sustain agricultural production in the Shenandoah Valley because of its financial, cultural, and economic importance to the region,” says Eric Bendfeldt, community viability Extension specialist.

Knowlton explains that researchers are “helping farmers meet federal and state environmental regulations.” With her colleagues, she is leading a study that offers incentives for dairy farmers to reduce phosphorus overfeeding on their farms. Using $1.3 million in grants from the U.S. Department of Agriculture and Virginia DCR, Virginia Tech is giving payments of up to $12 per cow each year to producers in the Shenandoah Valley who make changes in livestock diets.

In addition to helping farmers in the Chesapeake Bay Watershed improve the environment, Virginia Tech researchers are giving them new ways to make value-added products. For example, Greg Evanylo, professor of crop and soil environmental sciences and Extension composting specialist, has been studying the environmental effects of composted manure as a substitute for traditional methods of sediment and erosion control on disturbed lands, such as Virginia Department of Transportation-managed highway roadsides and construction sites. He has been teaching interested farmers how to learn to compost poultry litter as a value-added product. The Waste Solutions Forum determined that finding alternative uses and markets for these products is critical to solving the excess nutrient problem.

Nutrient management research in the Shenandoah Valley provides another example. Dairy farmers can use Arogo-Ogejo’s reactor to produce struvite, a crystal that can be used as a slow-release fertilizer, a compound in cleaning products and fire-resistant panels, a raw material for the phosphate industry, and a binding material in cements.

“Struvite is also much easier to carry and transport over long distances than dairy manure,” Arogo-Ogejo adds. “We can send the struvite to areas that are deficient in phosphorus and, because struvite has less volume than the alternative, transportation is cheaper.”

This also improves efficiency and generates cost savings, two other major ways that Virginia Tech research on the bay is helping sustain the livelihood of agricultural producers. Knowlton, in particular, is dealing with issues of agricultural efficiency in her phosphorus incentive program for dairy farmers. As a part of the study, a subset of the producers receiving incentive payments are participating in a program to further improve dairy practices to prevent waste and nutrient losses.

“We can formulate a diet that perfectly meets the needs of the cow, but between the time we get that formula and the time we feed the cow, the feeds may have changed,” Knowlton says. “Knowing there is a risk of imprecision, most farmers think, ‘I need to overfeed to create a margin of safety,’ but all margins of safety lead to waste.”

By helping dairy producers formulate a diet and improve their feeding practices, Knowlton and her team are stopping phosphorus and nitrogen pollution one farm at a time before it enters the bay.

What the future holds

Much of Virginia Tech’s research and outreach activities related to the Chesapeake Bay seek long-term solutions that work on a small part of the complex problem. Some progress has been made since the signing of the Chesapeake 2000 Agreement. For example, the bay’s striped bass populations remain in high numbers despite environmental stresses such as diminishing food supply, according to the most recent “State of the Bay” report. But if current trends prevail, scientists and legislators will not meet the goals set a decade ago.

“We have made some progress, but not on all fronts, and we are not going to meet the nutrient reduction goals for the bay by 2010,” Mostaghimi says. “We anticipate that the Environmental Protection Agency (EPA) will put the entire bay on a TMDL list at that time. This means that even small watersheds on the Chesapeake Bay basin must produce their own pollution reduction plan with the hope that, collectively, these small changes will lead to overall improvements in the bay’s health.”

A bay-wide TMDL and watershed improvement plan would be an enormous task and a necessary one if the EPA mandates it in 2010. “Currently, all states have their own TMDL program and the Chesapeake Bay Program does its own modeling to estimate pollutant loads entering the bay,” Benham says. “The Center for Watershed Studies at Virginia Tech is well positioned to use its TMDL-related watershed modeling and watershed management planning research and outreach expertise to contribute to the development of a bay-wide TMDL.”

Whatever road science eventually takes to solve the Chesapeake Bay’s water-quality and pollution programs, scientists at Virginia Tech are keeping their sights on the horizon, just as Captain John Smith did when he sailed into the bay in the summer of 1607. Smith encountered a beautiful estuary in the newly established Virginia colony teeming with rockfish, blue crabs, oysters, and shad, with clean water flowing over beds of eelgrass.

Aerial photo by Rick Griffiths.

Foster Agblevor, associate professor of biological systems engineering, is converting animal wastes, such as poultry litter; residues, such as cotton gin waste; and nonfood energy crops, such as switchgrass, to fuels and value-added products. Photo by John McCormick.

Virginia Tech researchers, from an agricultural engineer turning poultry litter into bio-oil to an economist searching for ways to revive the oyster aquaculture industry, are trying to restore this image of a vibrant Chesapeake Bay.

Photo by John McCormick.

Foster Agblevor is developing a transportable pyrolysis unit to convert poultry litter into bio-oil, producer gas, and fertilizer. The unit is set on the back of a large truck and moved from farm to farm. Photo courtesy of Foster Agblevor.

John Ignosh, area specialist in Extension’s Northwest District, demonstrates an on-farm nutrient removal reactor developed by Jactone Arogo-Ogejo at a test site in Dayton, Virginia. The cone-shaped reactor captures the phosphorus in dairy manure and converts it into a phosphate-rich crystal. Photo by John McCormick.

After the reactor converts dairy manure into struvite, the crystals must be dried on location, as shown here. Fine crystals of struvite are returned to the reactor to provide new seed material for further crystallization. Photo by John McCormick.

Struvite is a salt formed when equal molar concentrations of magnesium, ammonium, and phosphate ions in a solution react. The crystals can be used as a slow-release fertilizer and a raw material for a variety of industry products, such as fire-resistant panels. Photo by John McCormick.

Alex Miller, a graduate student in agriculture and applied economics at Virginia Tech (shown in the enlarged photo), and Bonnie Brown, associate professor of biology at Virginia Commonwealth University (shown in this thumbnail photo), deploy oyster floats. Each float holds about 600 oysters. Photo courtesy of Kurt Stephenson.

This native Chesapeake Bay oyster (Crassostrea virginica) grown at Circle C Oyster Ranchers, a project partner in Maryland, is ready for harvest. Project oysters grow from microscopic-size seeds to three or four inches in an average of 18 months, about half the time it takes in the wild. Mortality from disease is also substantially less in an aquaculture setting. And healthier oysters mean more water filtration. Photo courtesy of Kurt Stephenson.

A field trial site off the Little Wicomico Creek in Northumberland County, Virginia, was provided by project partners Lynton Land and Judith Lang. Photo courtesy of Kurt Stephenson.



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