TOP STORY: June 18, 2013
Litter research before Bay Program workgroup
By SEAN CLOUGHERTY
Managing Editor
With a meeting scheduled this week, the Agriculture Workgroup of the Chesapeake Bay Program is expected to further discuss and possibly recommend changes to how the program accounts for pollution from poultry litter in its modeling after University of Delaware research showed much fewer nutrients are coming from litter than federal regulators estimate.
According to a study of thousands of manure tests from several Bay watershed states, led by James Glancey, professor of bioresources engineering at UD, there are great discrepancies between his numbers and those arrived by using the Environmental Protection Agency’s standard, developed decades ago, as to how much poultry manure is produced annually on Delmarva and the nutrient content of the manure.
With more than 8,000 data points from Delaware, Maryland, Virginia and West Virginia, Glancey said actual nitrogen levels from poultry litter is about 55 percent less than EPA’s estimates.
Using Sussex County as a case study, Glancey said thousands of manure test results and data from hundreds of poultry house cleanouts and crust outs show the county produces more than five times less the amount of manure suggested by EPA annually, 261,723 tons versus 1.48 million tons.
Glancey also said from the study, there’s about 20 million pounds less nitrogen generated from poultry litter than EPA model claim and about 4 million pounds less phosphorus.
“That’s substantial enough that we need to get this right and get this into the model,” Glancey said.
Glancey said improvements in bird genetics, feed technology and better growing practices than in the past have reduced the amount of manure produced in poultry farms, changes which don’t seem to factor into the standard EPA uses.
Glancey said modelers at the CPB have been working with researchers to determine how to better understand and integrate the data.
The Agriculture Workgroup is scheduled to meet on June 20, according to the CBP’s website. Once the research is reviewed by the workgroup, it can decide to make recommendations to the CBP which has a separate review process in considering changes to the model.
In 2011, the CBP’s Agriculture Workgroup created the Poultry Litter Subcommittee, charged with collecting data that better reflects modern nutrient generation from poultry production and offer recommendations to the workgroup to improve modeling.
Initial recommendations from the subcommittee were to allow each state to report its annual average nitrogen and phosphorus manure concentrations and generation volumes, and to directly utilize the data where available in place of current model data.
While hailed by the agriculture industry as sound and accurate research, Glancey’s research has come under some scrutiny.
Alison Fairbrother, director of the Public Trust Project, a scientific research watchdog group, said any conclusions from the research are premature as it has had no peer review and is only preliminary for the workgroup to review.
She added that the research doesn’t account for variations in cleanout strategies or bird age which could impact the results.
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