title: The effects of pesticides on bacterial nitrogen fixers in peanut-growing area.
abstract: In the peanut production, the applications of herbicides and fungicides are a common practice. In this work, studies done under field conditions demonstrated that pesticides affected negatively the number and nitrogenase activity of diazotrophic populations of soil. Agrochemical effects were not transient, since these parameters were not recovered to pre-treatment levels even 1 year after pesticides application. Results obtained from greenhouse experiments revealed that the addition of herbicide or fungicides diminished the free-living diazotrophs number reaching levels found in soil amended with the pesticides and that the number of symbiotic diazotrophs was not affected by the insecticide assayed. The soil nitrogenase activity was not affected by fungicides and glyphosate. The effect of pesticides on the nitrogen-fixing bacteria diversity was evaluated both in field and greenhouse experiments. Analysis of clone libraries generated from the amplification of soil nifH gene showed a diminution in the genetic diversity of this bacterial community.
authors: Departamento de Ciencias Naturales, Facultad de Ciencias Exactas, Físico-Químicas y Naturales, Universidad Nacional de Río Cuarto, Enlace Rutas 8 y 36 km 601, 5800, Río Cuarto, Córdoba, Argentina, jangelini@exa.unrc.edu.ar.
authors: Jorge
authors: J
authors: Angelini
authors: Ghio
authors: G
authors: Silvina
authors: Tania
authors: T
authors: Taurian
authors: Fernando
authors: F
authors: Ibáñez
authors: María Laura
authors: ML
authors: Tonelli
authors: Lucio
authors: L
authors: Valetti
authors: María Soledad
authors: MS
authors: Anzuay
authors: Liliana
authors: L
authors: Ludueña
authors: Vanina
authors: V
authors: Muñoz
authors: Adriana
authors: A
authors: Fabra
mesh_terms: D010367:Arachis / Q000382:microbiology*; D001419:Bacteria / Q000145:classification* / Q000187:drug effects / Q000235:genetics; D005659:Fungicides, Industrial / Q000494:pharmacology*; D005998:Glycine / Q000031:analogs & derivatives / Q000494:pharmacology; D009586:Nitrogen Fixation; D010088:Oxidoreductases / Q000235:genetics; D010575:Pesticides / Q000494:pharmacology*; D010802:Phylogeny; D012988:Soil Microbiology; D000097797:Glyphosate
chemical_list: D005659:Fungicides, Industrial; D005998:Glycine; D010088:Oxidoreductases; D010575:Pesticides; D000097797:Glyphosate; C029130:nitrogenase reductase