Submitted to: American Society of Agronomy Meetings
Publication Type: Abstract Only
Publication Acceptance Date: 7/15/2003
Publication Date: 11/1/2003
Citation: Moore Jr, P.A., Daniel, T.C., Edwards, D.R. 2003. Long-term effects of alum-treated poultry litter, normal litter and ammonium nitrate on soil chemical properties and plant growth [CD-ROM]. Denver, CO: American Society of Agronomy Meetings.
Technical Abstract: Alum additions to poultry litter have been shown to greatly reduce phosphorus (P) runoff and ammonia emissions. However, there have been no long-term studies on the effects of alum-treated litter on soil chemistry. 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. Fifty two small plots were established on a Captina silt loam soil. 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 five 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 poultry litter or ammonium nitrate.