title: Phosphorus runoff losses from subsurface-applied poultry litter on coastal plain soils.
abstract: The application of poultry litter to soils is a water quality concern on the Delmarva Peninsula, as runoff contributes P to the eutrophic Chesapeake Bay. This study compared a new subsurface applicator for poultry litter with conventional surface application and tillage incorporation of litter on a Coastal Plain soil under no-till management. Monolith lysimeters (61 cm by 61 cm by 61 cm) were collected immediately after litter application and subjected to rainfall simulation (61 mm h(-1) 1 h) 15 and 42 d later. In the first rainfall event, subsurface application of litter significantly lowered total P losses in runoff (1.90 kg ha(-1)) compared with surface application (4.78 kg ha(-1)). Losses of P with subsurface application were not significantly different from disked litter or an unamended control. By the second event, total P losses did not differ significantly between surface and subsurface litter treatments but were at least twofold greater than losses from the disked and control treatments. A rising water table in the second event likely mobilized dissolved forms of P in subsurface-applied litter to the soil surface, enriching runoff water with P. Across both events, subsurface application of litter did not significantly decrease cumulative losses of P relative to surface-applied litter, whereas disking the litter into the soil did. Results confirm the short-term reduction of runoff P losses with subsurface litter application observed elsewhere but highlight the modifying effect of soil hydrology on this technology's ability to minimize P loss in runoff.
authors.affiliation: Dep. of Agriculture, Food, and Resource Sciences, Univ. of Maryland Eastern Shore, Princess Anne, MD 21853, USA. lckibet@umes.edu
authors.forename: Leonard C
authors.initials: LC
authors.lastname: Kibet
authors.forename: Arthur L
authors.initials: AL
authors.lastname: Allen
authors.forename: Peter J A
authors.initials: PJ
authors.lastname: Kleinman
authors.forename: Gary W
authors.initials: GW
authors.lastname: Feyereisen
authors.forename: Clinton
authors.initials: C
authors.lastname: Church
authors.forename: Lou S
authors.initials: LS
authors.lastname: Saporito
authors.forename: Thomas R
authors.initials: TR
authors.lastname: Way
mesh_terms: D000383:Agriculture / Q000379:methods*; D000818:Animals; D005308:Fertilizers; D008372:Manure; D008396:Maryland; D010758:Phosphorus / Q000378:metabolism*; D011200:Poultry; D011891:Rain; D014872:Water Movements; D014873:Water Pollutants / Q000378:metabolism*; D014881:Water Supply
chemical_list: D005308:Fertilizers; D008372:Manure; D014873:Water Pollutants; D010758:Phosphorus