title: Repeated application of composted tannery sludge affects differently soil microbial biomass, enzymes activity, and ammonia-oxidizing organisms.
abstract: Repeated application of composted tannery sludge (CTS) changes the soil chemical properties and, consequently, can affect the soil microbial properties. The aim of this study was to evaluate the responses of soil microbial biomass and ammonia-oxidizing organisms to repeated application of CTS. CTS was applied repeatedly during 6 years, and, at the sixth year, the soil microbial biomass, enzymes activity, and ammonia-oxidizing organisms were determined in the soil. The treatments consisted of 0 (without CTS application), 2.5, 5, 10, and 20 t ha(-1) of CTS (dry basis). Soil pH, EC, SOC, total N, and Cr concentration increased with the increase in CTS rate. Soil microbial biomass did not change significantly with the amendment of 2.5 Mg ha(-1), while it decreased at the higher rates. Total and specific enzymes activity responded differently after CTS application. The abundance of bacteria did not change with the 2.5-Mg ha(-1) CTS treatment and decreased after this rate, while the abundance of archaea increased significantly with the 2.5-Mg ha(-1) CTS treatment. Repeated application of different CTS rates for 6 years had different effects on the soil microbial biomass and ammonia-oxidizing organisms as a response to changes in soil chemical properties.
authors.affiliation: Soil Quality Laboratory Agricultural Science Center, Federal University of Piauí, Teresina, PI, Brazil. asfaruaj@yahoo.com.br.
authors.forename: Ademir Sérgio Ferreira
authors.initials: AS
authors.lastname: Araújo
authors.affiliation: Soil Quality Laboratory Agricultural Science Center, Federal University of Piauí, Teresina, PI, Brazil.
authors.forename: Luciano Moura
authors.initials: LM
authors.lastname: Lima
authors.affiliation: Soil Quality Laboratory Agricultural Science Center, Federal University of Piauí, Teresina, PI, Brazil.
authors.forename: Vilma Maria
authors.initials: VM
authors.lastname: Santos
authors.affiliation: Department of Land, Air and Water Resources, University of California, Davis, CA, 95616, USA.
authors.forename: Radomir
authors.initials: R
authors.lastname: Schmidt
mesh_terms: D000641:Ammonia / Q000378:metabolism* / Q000633:toxicity; D001105:Archaea / Q000187:drug effects; D001419:Bacteria / Q000187:drug effects / Q000201:enzymology; D018533:Biomass; D007220:Industrial Waste; D010084:Oxidation-Reduction; D012722:Sewage / Q000737:chemistry; D012987:Soil / Q000737:chemistry; D012988:Soil Microbiology; D012989:Soil Pollutants / Q000032:analysis / Q000378:metabolism* / Q000633:toxicity; D013633:Tanning; D014865:Waste Disposal, Fluid / Q000379:methods
chemical_list: D007220:Industrial Waste; D012722:Sewage; D012987:Soil; D012989:Soil Pollutants; D000641:Ammonia
keywords: Ammonia-oxidizing archaea; Ammonia-oxidizing bacteria; Environmental pollution; Microbial activity; Wastes