Curbs on poultry fertilizer could hurt bay, study says

Sending litter elsewhere could be harmful, it says

April 02, 2004|By Dennis O'Brien | Dennis O'Brien,SUN STAFF

A University of Maryland researcher says new regulations that restrict the use of poultry litter as fertilizer on the Eastern Shore might damage Chesapeake Bay water quality rather than improve it.

Kenneth W. Staver, an agricultural engineer, found in a $200,000 study that if poultry farmers clustered on the lower Eastern Shore are forced to send poultry litter to other areas, it could increase runoff of harmful nutrients.

The Upper Eastern Shore would be a likely destination for the poultry litter, but the area's hilly terrain and less porous soils pose a problem.

"As you move up the shore, you have steeper slopes and the potential for runoff goes up," Staver said.

The study by the Maryland Center for Agro-Ecology Inc., was funded by two farm groups, the Maryland Grain Producers Utilization Board and the Delmarva Poultry Industry Inc. An executive summary was released yesterday.

Scientists blamed nutrient runoff for an outbreak of fish-killing Pfiesteria piscicida bacteria in 1997, prompting legislation that requires stringent management plans for manure-fertilized fields. Maryland's poultry industry generates about 800 million pounds of chicken manure each year.

The Water Quality Improvement Act requires poultry farmers to come up with nutrient management plans, test soils for pollutants and ship poultry litter to other sites if soils exceed specific limits for phosphorus and nitrogen, said Louise Lawrence, chief of the Maryland Department of Agriculture's Office of Resource Conservation.

But Staver found that nutrient runoff, particularly phosphorus, could increase if farmers ship manure elsewhere in the watershed.

The findings are based on runoff measured at two adjacent 30-acre plots at University of Maryland facilities in Queen Anne's County.

The findings also showed that using inorganic fertilizers, such as those sold in feed stores, makes it easier to determine how much fertilizer a field needs than using poultry litter, whose effectiveness depends on air temperature and other variables.

In addition, the study showed that nutrient runoff was three to four times greater in a plot where researchers used "no-till" agriculture, a popular method of planting where the soil remains undisturbed by plows.

Farmers said they hope state regulators review the findings before they fine-tune bay regulations in the years ahead.

"I think what's normal and usual and recommended today may not be the same things we see in the future," said Stephen L. Weber, a former president of the Maryland Farm Bureau and vice president of Agro-Ecology's board of directors.

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