Long-term effects of alum-treated poultry litter, untreated litter and ammonium nitrate on soil chemistry and plant growth.
(A05-moore699706-oral)
Authors:
P.A. Moore* - USDA/ARS; Fayetteville, AR T.C. Daniel - U of A/CSES
D.R. Edwards - U of K/Biol. Eng.
Abstract:
Alum additions to poultry litter have been shown to greatly reduce phosphorus (P) runoff and ammonia emissions. A 20 year experiment was initiated in 1995 to determine the effects of poultry litter,
alum-treated poultry litter and ammonium nitrate on soil chemistry, P runoff and forage yields. There were 13 treatments; four rates of normal poultry litter, four rates of alum-treated litter, four rates of ammonium nitrate and an unfertilized control. Litter application rates were 2.24, 4.49, 6.73 and 8.98 Mg/ha. Ammonium nitrate rates were 65, 130, 195 and 260 kg N/ha, which were the same N rates as alum-treated litter. Both untreated litter and alum-treated litter had a net liming effect on the soil, with pHs increasing over time, particularly at the higher rates. Ammonium nitrate applications acidified the soil. Whereas exchangeable aluminum levels were very low (~ 1 mg Al/kg) in soils amended with alum-treated or normal litter, soils fertilized with ammonium nitrate had elevated Al levels (up to 100 mg Al/kg), due to acidic soil conditions, resulting in poor forage growth. Although ammonium nitrate resulted in slightly higher yields in years 1 and 2, alum-treated litter has resulted in the highest yields during the past six years. Phosphorus leaching was much lower with alum-treated litter than normal litter. These results indicate that fertilizing with alum-treated litter is more sustainable than fertilizing with normal litter or ammonium nitrate.
Speaker Information: Philip Moore, USDA/ARS; Fayetteville, AR, Plant Sciences Rm 115 University of Arkansas, Fayetteville, AR 72701; Phone: 479-575-5724; E-mail: [email protected]
Session Information: Monday, November 3, 2003, 12:55 PM-3:00 PM Presentation Start: 2:00 PM
Keywords: Long-term; effects; of; alum-treated litter