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| Carrasco-Letelier,Leonidas; Mendoza,Yamandu; Ramallo,Gustavo. |
| This work studies the acute contact toxicity of oxalic acid (OA) on a honeybee polyhybrid subspecies (Apis mellifera), which is the dominant biotype in southwestern zone of Uruguay (SWZU) and the country's most important honey-producing region. We determined the mean lethal dose (LD50), as well as the no observed effect level (NOEL) and the lowest observed effect level (LOEL) values. We also estimated the total number of honeybees per hive in the test area. The aim was to assess the relationship between the maximum OA dose used in Uruguay (3.1 g OA per hive) and the toxicological parameters of honeybees from SWZU. The current dose of 3.1 g OA per hive corresponds to 132.8 OA per honeybee since determined NOEL is 400 OA per honeybee; our results indicate... |
| Tipo: Journal article |
Palavras-chave: LD50; Uruguay. |
| Ano: 2012 |
URL: http://www.scielo.cl/scielo.php?script=sci_arttext&pid=S0718-58392012000200019 |
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| Carrasco-Letelier,Leonidas; Beretta-Blanco,Andrés. |
| Abstract Soil erosion can be accelerated by agricultural intensification, and the soil loss can alter the quality of water bodies. Sustainable agricultural production therefore requires the management of erosion and potential water pollution. In Uruguay, where there is heavy use of soil for agriculture, there is a need to continually develop and update erosion management policies. In this framework, we estimated the erosion in 99 drainage basins by analyzing and managing the information required (K, L, S, C and R-factors) in the universal soil loss equation (USLE) and the revised universal soil loss equation (RUSLE) in a geographical information system (GIS). The studied drainage basins encompass 73% of the area of Uruguay. The results include the... |
| Tipo: Journal article |
Palavras-chave: Erosion; GIS; RUSLE; USLE; Watersheds. |
| Ano: 2017 |
URL: http://www.scielo.cl/scielo.php?script=sci_arttext&pid=S0718-16202017000200184 |
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| Beretta-Blanco,Andrés; Carrasco-Letelier,Leonidas. |
| Soil erosion by rainfall is a process that demands management, both for the prevention of excessive soil erosion and for the protection of the quality of freshwater bodies. Erosion coefficients (K-factors) of the universal soil loss equation (USLE)/revised USLE (RUSLE) model were assigned to 99 mapped Uruguayan soil types at 1:1,000,000 scale. This work developed a linear mixed model (LMM) with 79 soils with assigned K-factors, in which the following variables were considered: soil taxonomy, chemical composition, and parent material. The developed LMM had an R²=0.86, in which the soil taxonomy (p<0.0001), parent material (p=0.0174), clay (p=0.0005) and sand (p=0.017) contents had significant statistical effects. The prediction capacity of this model was... |
| Tipo: Journal article |
Palavras-chave: Soil classification; Parent material; Soil texture; Soil chemistry. |
| Ano: 2017 |
URL: http://www.scielo.cl/scielo.php?script=sci_arttext&pid=S0718-16202017000100011 |
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