Santos C.A.,Estadual de Londrina |
Santos C.A.,University of Sao Paulo |
Panchoni L.C.,Estadual de Londrina |
Bini D.,University of Sao Paulo |
And 10 more authors.
Journal of Environmental Quality | Year: 2013
Landfill leachates are pollutants rich in ammoniacal N, Na, and K, but land application potentially offers an alternative for recycling these leachate nutrients. We applied landfi ll leachate corresponding to 0, 110, 220, 330, and 440 kg ha-1 of total N, divided in three applications ( July, August, and October 2008), onto the surface of an acidic (pH 5.5-6.0) clay (79% clay) Ultisol and monitored NH3 volatilization just after applications and microbiological (0-10 cm) and chemical attributes (0-60-cm soil depth) in August 2008, January 2009, and May 2009. Ammonium (up to 30 mg kg-1), NO3 - (up to 160 mg kg-1), Na, K (up to 1.1 cmolc kg-1 each), and electrical conductivity (up to 1 dS m-1) increased transiently in soil following applications. Despite >90% of the total leachate N being ammoniacal, NO3 - predominated in the first soil sampling, 14 d aft er the second application, suggesting fast nitrifi cation, but it decreased in the soil profi le thereafter. From 5 to 25% of the total applied N volatilized as NH3, with maximum losses within the fi rst 3 d. Applications inhibited (50%) the relative nitrifi cation rate and increased (50%) hot-water-soluble carbohydrates in the soil at the highest rate. No effects were observed on soil microbial biomass C (114-205 mg kg-1) and activity (5-8 mg CO2-C kg-1 d-1) or on corn grain yields (6349-7233 kg ha-1). Controlled land application seems to be a viable alternative for landfi ll leachate management, but NO3 - leaching, NH3 volatilization, and accumulation of salinizing ions must be monitored in the long term to prevent environmental degradation. © American Society of Agronomy, Crop Science Society of America, and Soil Science Society of America. Source