title: Microbial, physical and chemical properties of irrigation water in rice fields of Southern Brazil.
abstract: This paper presents the results of the statistical analysis of microbiological, physical and chemical parameters related to the quality of the water used in rice fields in Southern Brazil. Data were collected during three consecutive crop years, within structure of a comprehensive monitoring program. The indicators used were: potential hydrogen, electrical conductivity, turbidity, nitrogen, phosphorus, potassium, calcium, total and fecal coliforms. Principal Component and Discriminant Analysis showed consistent differences between the water irrigation and drainage, as the temporal variation demonstrated a clear reduction in the concentration of most of the variables analyzed. The pattern of this reduction is not the same in the two regions - that is, the importance of each of the different variables in the observed differentiation is modified in two locations. These results suggested that the variations in the water quality utilized for rice irrigation was influenced by certain specific aspects of each rice region in South Brazilian - such as anthropic action or soil/climate conditions in each hydrographic basin.
authors.affiliation: Laboratório de Microbiologia e Toxicologia, Universidade do Vale do Rio dos Sinos, São Leopoldo, RS, Brazil.
authors.forename: Maria Helena L R
authors.initials: MH
authors.lastname: Reche
authors.affiliation: Laboratório de Microbiologia e Toxicologia, Universidade do Vale do Rio dos Sinos, São Leopoldo, RS, Brazil.
authors.forename: Vilmar
authors.initials: V
authors.lastname: Machado
authors.affiliation: Laboratório de Microbiologia e Toxicologia, Universidade do Vale do Rio dos Sinos, São Leopoldo, RS, Brazil.
authors.forename: Danilo A
authors.initials: DA
authors.lastname: Saul
authors.affiliation: Estação Experimental do Arroz, IRGA, Cachoeirinha, RS, Brasil.
authors.forename: Vera R M
authors.initials: VR
authors.lastname: Macedo
authors.affiliation: Estação Experimental do Arroz, IRGA, Cachoeirinha, RS, Brasil.
authors.forename: Elio
authors.initials: E
authors.lastname: Marcolin
authors.affiliation: Laboratório de Microbiologia e Toxicologia, Universidade do Vale do Rio dos Sinos, São Leopoldo, RS, Brazil.
authors.forename: Neiva
authors.initials: N
authors.lastname: Knaak
authors.affiliation: Laboratório de Microbiologia e Toxicologia, Universidade do Vale do Rio dos Sinos, São Leopoldo, RS, Brazil.
authors.forename: Lidia M
authors.initials: LM
authors.lastname: Fiuza
mesh_terms: D057914:Agricultural Irrigation; D001938:Brazil; D005618:Fresh Water / Q000032:analysis* / Q000737:chemistry / Q000382:microbiology; D012275:Oryza; D014871:Water Microbiology