title: Phosphatase activity and its relationship with physical and chemical parameters during vermicomposting of filter cake and cattle manure.
abstract: BACKGROUND
  Recycling of phosphorus (P) from organic residues (ORs) is important to develop environmentally friendly agriculture. The use of this P source depends on phosphatase enzymes, which can be affected by a chain of parameters during maturation of ORs. In this study the phosphatase activity levels throughout vermicomposting of filter cake (FC) and cattle manure (CM) were correlated with different physical and chemical parameters in an effort to increase the knowledge about recycling of P from ORs.
  
  
  RESULTS
  FC presented higher total nitrogen content (TNC), total organic carbon (TOC), humic acid (HA) content, water-soluble P (WSP), phosphatase activities and nanopore volume than CM during vermicomposting. Decreases in TOC of CM resulted from carbohydrate mineralization, which was not observed for FC. CM showed increased hydrophobic index during vermicomposting while FC showed a slight decrease.
  
  
  CONCLUSIONS
  Phosphatase activities correlated positively with TOC, pH and WSP and negatively with HA content for both vermicomposts. Nanopore volume was negatively correlated with phosphatase activities for FC but not for CM. No correlations between hydrophobicity and phosphatase activities were found for FC. Increased hydrophobicity throughout vermicomposting of CM could be partially associated with decreases in phosphatase levels.
authors: Faculdade de Agronomia e Medicina Veterinária, Universidade de Brasília, Campus Universitário Darcy Ribeiro, Caixa Postal 4508, CEP 70910-970, Brasília, (DF), Brazil.
authors: Jader Galba
authors: JG
authors: Busato
authors: Gruppo RICICLA, Dipartimento di Produzione Vegetale, Università degli Studi di Milano, Via Celoria 02, I-20133, Milan (MI), Italy.
authors: Gabriella
authors: G
authors: Papa
authors: NUDIBA, Universidade Estadual do Norte Fluminense Darcy Ribeiro, Avenida Alberto Lamego, 2000, CEP 28013-303, Campos dos Goytacazes, (RJ), Brazil.
authors: Luciano Pasqualoto
authors: LP
authors: Canellas
authors: Gruppo RICICLA, Dipartimento di Produzione Vegetale, Università degli Studi di Milano, Via Celoria 02, I-20133, Milan (MI), Italy.
authors: Fabrizio
authors: F
authors: Adani
authors: Instituto de Química, Universidade de Brasília, Campus Universitário Darcy Ribeiro, CEP 70910-970, Brasília, (DF), Brazil.
authors: Aline Lima
authors: AL
authors: de Oliveira
authors: Faculdade de Agronomia e Medicina Veterinária, Universidade de Brasília, Campus Universitário Darcy Ribeiro, Caixa Postal 4508, CEP 70910-970, Brasília, (DF), Brazil.
authors: Tairone Paiva
authors: TP
authors: Leão
mesh_terms: D000135:Acid Phosphatase / Q000737:chemistry*; D000822:Animal Husbandry; D000818:Animals; D002417:Cattle; D003247:Conservation of Natural Resources; D003612:Dairying; D005260:Female; D006812:Humic Substances; D008372:Manure
chemical_list: D006812:Humic Substances; D008372:Manure; D000135:Acid Phosphatase
keywords: CP-MAS 13C NMR spectroscopy; humic-enzyme interactions; organic phosphorus; organic residues; recycling