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Junod,Julio; Zagal,Erick; Sandoval,Marco; Barra,Ricardo; Vidal,Gladys; Villarroel,Mario. |
Water flows provided by irrigation systems may be associated with dissolved organic carbon (DOC) content in the soil solution and may modify the mobility of pesticides, such as chlorpyrifos (CHP). These compounds were analyzed under field conditions, evaluating their distribution in the soil profile under excessive irrigation in a Humic Haploxerand soil. The trial was carried out in soil columns located under the canopy of apple trees (Malus domestica Borkh.) in an orchard located in the Bío-Bío Region, Chile. The insecticide CHP was applied 120 g hL-1, and later the natural run off was collected from the foliage to the columns. Surface irrigation was used as a control, the equivalent to 4 L h-1 weekly, plus two treatments over the columns of 6 and 8 L h-1... |
Tipo: Journal article |
Palavras-chave: Pesticides; Organic matter; Volcanic soil. |
Ano: 2009 |
URL: http://www.scielo.cl/scielo.php?script=sci_arttext&pid=S0718-58392009000300017 |
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Celis,José; Sandoval,Marco; Barra,Ricardo. |
The potential toxicity of urban sewage and farmed salmon sludge, as well as their fertilizer potential, was evaluated by a battery of tests carried out with lettuce (Lactuca sativa L.) and annual ryegrass (Lolium multiflorum Lam.) cv. Winter Star. Wastes were evaluated in a Patagonian soil (Andic cryofluvent) and a granitic soil (Ultic Palexeralf). The treatments were municipal sewage sludge (MSS), salmon ground-farming waste (PSW) and salmon lake-farming waste (LSW) at different rates: 25, 50, 75, 100 and 150 t ha-1. Bioassays in lettuce were conducted for germination index (GI), radicle and hypocotyl structure length. Test in ryegrass were conducted for aboveground biomass yield. The phytotoxicological results from Patagonian soil showed significant... |
Tipo: Journal article |
Palavras-chave: Fish sludge; Salmon waste; Urban sludge; Organic fertilizer; Degraded soil. |
Ano: 2008 |
URL: http://www.scielo.cl/scielo.php?script=sci_arttext&pid=S0718-58392008000300007 |
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Chiang,Gustavo; Munkittrick,Kelly R; McMaster,Mark E; Tucca,Felipe; Saavedra,M. Fernanda; Ancalaf,Andrea; Gavilán,Juan F; Unzueta,Luis; Barra,Ricardo. |
There is scarce basic biological data on native freshwater fish species from Chile and next to zero on growth, gonad development and reproduction, which are critical for the purposes of the conservation of their natural populations. Seasonal analysis of sub-individual (oocyte development) and population (length frequency, growth rates) endpoints in Trichomycterus areolatus and Percilia gillissi were evaluated from February 2007 to January 2008. Oocyte development has a marked seasonality for P. gillissi, with mature eggs in October and declining frequency of mature oocytes into January. For T. areolatus we found some mature eggs in July, with highest number of mature eggs in October, coincident with previous data on maximum gonad size. Both species showed... |
Tipo: Journal article |
Palavras-chave: Seasonal cycles; Native fish Chile; Oocyte development; Multiple spawning reproductive strategy; Population size-structure. |
Ano: 2012 |
URL: http://www.scielo.cl/scielo.php?script=sci_arttext&pid=S0717-65382012000300006 |
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Junod,Julio; Zagal,Erick; Sandoval,Marco; Venegas,Alejandro; Campos,Jorge; Radrigan,Rudi; Barra,Ricardo; Vidal,Gladys. |
El presente estudio tiene por objetivo probar mediante ensayos supervisados la variabilidad de los residuos de clorpirifos (CHP) asociados a una metodología de muestreo validada en terreno, al aplicar el ingrediente activo (IA) en huerto de manzanos, con dos diferentes metodologías de aspersión y en épocas diferentes de desarrollo vegetativo. Se estudió la persistencia al aplicar 1,8 kg ha -1(Lorsban 50%WP®, Dow AgroScience, USA), mediante nebulizadora con bomba de espalda con motor (NBEM) y con nebulizadora de alto volumen (NAV). Se evaluó el modelo que representa el mejor ajuste de la declinación de los residuos a través de regresión no lineal. Los resultados muestran altos coeficientes de variación (CV) en ambos métodos de aplicación, NBEM (69%) y NAV... |
Tipo: Journal article |
Palavras-chave: Pesticidas; Residuos; Degradación. |
Ano: 2009 |
URL: http://www.scielo.cl/scielo.php?script=sci_arttext&pid=S0718-27912009000300002 |
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