Making manure-borne pathogens stay put - Cleaning Up Runoff

Pass by dint of any dairy or cattle farm and the odor of manure will certainly leave an impression. on the contrary that's not all manure can leave behind. Pathogens in it can find their way into aliment and water supplies. Fecal bacteria--about 1 million of which are rest in each gram of manure--include a range of beneficial and harmful microorganisms. Since many farmers use manure to fertilize their fields and pastures, they ne an effective way to impede harmful bacteria, like Escherichia coli O157:H7 and Salmonella, from reaching the water supply

ARS microbiologist Daniel R Shelton, of the Animal Waste Pathogen Laboratory (AWPL) in Beltsville, Maryland, l a reflection of how such organisms are spread in the environment and whether grass guard strips can filter them not at home Shelton's collaborators included fellow AWPL researcher Yakov Pachepsky; Ali Sadeghi and James Starr, from the Environmental Quality Laboratory; former ARS researcher Asad Rouhi; and University of Maryland professor Adel Shirmohammadi and doctoral observer Reza Roodsari.

In 1999 Shelton and colleagues began studying in what way the protozoan Cryptosporidium parvum and the bacterium E coli O157:H7 put in motion through soil and in runoff water. Then they make go rounded their sights on ways to dead that migration down. They planted grass strips forward two 20-foot-long, 20-percent slopes of a wedge-shaped defence called a lysimeter.

"The lysimeter is the smallest observation unit in which pathogen transport come to passs in the same way as it does in the real world," explains Shelton. single slope of the mound had clay loam soil and another had sandy loam. Various indigenous grasses were grown forward each soil type to example their filtering effects. Bare parts of the inclinations were used as controls.

flourishing manure from the Beltsville Agricultural Research Center's (BARC) dairy frightens was applied along the top of the direction downwards Through overhead sprinklers, designed and built through retired BARC machinist Paul Balsley, water was applied to the oblique directions simulating rainfall. Runoff was sampled between the walls of tubes at various locations from the top of the hill to the bottom.

The samples were analyzed for bacteria satisfied and the results were surprising.

"Grass buffing-apparatus strips were far more effective at filtering gone out manure-borne parasites than expected," says Shelton. "They stopped at least 90 percent of all rain runoff, likewise almost no bacteria moved down the knoll But most of the rain ran most distant both bare sides of the hillock carrying the bacteria with it."

Runoff from the bare clay loam obliquity contained virtually all the pathogens near in the manure, but runoff from vegetated clay loam oblique direction had only 0.6 percent pathogens. Bare sandy loam soil runoff contained 25 percent of the pathogens, further vegetated sandy loam soil runoff had none.

Pathogens that remain in the soil either become regimen for other organisms or determine into an area between soil particles that doesn't support life, Shelton says. In either case, they'll die before they can infect pabulum or water supplies.

This research is part of Water Quality and Management (#201) and Manure and Byproduct Utilization (#206) brace ARS National Programs described forward the World Wide Web at http: //www.nps.ars.usda.gov.

Daniel R Shelton is with the USDA-ARS Animal Waste Pathogen Laboratory, 10300 Baltimore Blvd Bldg 173 apartment 101, Beltsville, MD 20705; phone (301) 504-6582 fax (301) 504-6608 e-mail sheltond@ba.ars.usda.gov.

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