title: Reducing Phosphorus Runoff and Leaching from Poultry Litter with Alum: Twenty-Year Small Plot and Paired-Watershed Studies.
abstract: Treating poultry litter with alum has been shown to lower ammonia (NH) emissions and phosphorus (P) runoff losses. Two long-term studies were conducted to assess the effects of alum-treated poultry litter on P availability, leaching, and runoff under pasture conditions. From 1995 to 2015, litter was applied annually in a paired watershed study comparing alum-treated and untreated litter and in a small plot study comparing 13 treatments (an unfertilized control, four rates of alum-treated litter, four rates of untreated litter, and four rates of NHNO). In the paired watershed study, total P loads in runoff were 231% higher from pasture receiving untreated litter (1.96 kg P ha) than from that receiving alum-treated litter (0.85 kg P ha). In both studies, alum-treated litter resulted in significantly higher Mehlich III P (M3-P) and lower water-extractable P at the soil surface, reflecting greater retention of applied P and lesser availability of that P to runoff or leaching. In soils fertilized with alum-treated litter, M3-P was much higher when analyzed by inductively coupled argon plasma emission spectrometry than by colorimetry, possibly due to the formation of aluminum phytate. Indeed, alum-treated poultry litter leached less P over the 20-yr study: M3-P at 10 to 50 cm was 266% greater in plots fertilized with untreated litter (331 kg M3-P ha) than with alum-treated litter (124 kg M3-P ha). This research provides compelling evidence that treating poultry litter with alum provides short-term and long-term benefits to P conservation and water quality.
authors.forename: Lidong
authors.initials: L
authors.lastname: Huang
authors.forename: Philip A
authors.initials: PA
authors.lastname: Moore
authors.forename: Peter J A
authors.initials: PJ
authors.lastname: Kleinman
authors.forename: Kyle R
authors.initials: KR
authors.lastname: Elkin
authors.forename: Mary C
authors.initials: MC
authors.lastname: Savin
authors.forename: Daniel H
authors.initials: DH
authors.lastname: Pote
authors.forename: Dwayne R
authors.initials: DR
authors.lastname: Edwards
mesh_terms: D000534:Alum Compounds; D000818:Animals; D008372:Manure; D010758:Phosphorus / Q000032:analysis*; D011200:Poultry; D012987:Soil; D014872:Water Movements
chemical_list: D000534:Alum Compounds; D008372:Manure; D012987:Soil; D010758:Phosphorus; C041524:aluminum sulfate