Soil erosion is a relevant factor in land degradation, causing several negative impacts to different levels in the environment, agriculture, etc. The tobacco plantations in the western part of the country have been negatively affected by the water erosion due to natural and human factors. For the implementation of a strategy for sustainable land management a key element is to quantify the soil losses in order to establish policies for soil conservation. The nuclear techniques have advantages in comparison with the traditional methods to assess soil erosion and have been applied in different agricultural settings worldwide. The tobacco cultivation in Pinar del Río is placed on soils with high erosion levels, therefore is important to apply techniques which support the soil erosion rate quantification. This work shows the use of 137Cs technique to characterize the soil erosion status in two sectors in a farm with tobacco plantations located in the south-western plain of Pinar del Rio province. The sampling strategy included the evaluation of selected transects in the slope direction for the studied site. The soil samples were collected in order to incorporate the whole 137Cs profile. Different conversion models were applied and the Mass Balance Model II provided the more representative results, estimating the soil erosion rate from –18,28 to 8,15 t ha-1año-1

La erosión del suelo es un elemento importante en la degradación de tierras, provocando impactos negativos a varios niveles (parcela, finca, cuenca, etc). El cultivo del tabaco en el occidente del país se ha visto negativamente afectado por la erosión hídrica asociado a factores naturales y antrópicos. Un elemento fundamental para implementar una estrategia de manejo sostenible de tierras es la cuantificación de las pérdidas de suelo, ya que permiten establecer políticas de conservación de suelos. Las técnicas nucleares en la evaluación de la erosión, poseen ventajas en comparación con los métodos tradicionales y han sido aplicadas en diferentes agrosistemas a nivel mundial. En la provincia Pinar del Río, los suelos dedicados al cultivo del tabaco, presentan elevados niveles erosivos, por lo que es importante utilizar técnicas que permitan la cuantificación de las tasas de erosión de suelos. El trabajo muestra el uso de la técnica del 137Cs para caracterizar el estado de la erosión de suelos en dos sectores de una granja con plantaciones de tabaco, ubicadas en la Llanura Suroccidental de la provincia de Pinar del Río. La estrategia de muestreo incorporó la evaluación de transectas seleccionadas en dirección de la pendiente, siendo tomadas muestras de suelos que incluyeron todo el 137Cs del perfil. Se emplearon varios modelos de conversión; el Modelo de Balance de Masa II proporcionó los mejores resultados, obteniéndose una tasa de redistribución de suelos con valores de -18,28 a 8,15 t ha-1año-1

Informações sobre carrapatos autóctones e seus hospedeiros são escassas na América do Sul, especialmente para a Argentina. Com o objetivo de contribuir para o conhecimento dos carrapatos na região, 2094 carrapatos foram coletados da vegetação, de humanos e de animais domésticos e selvagens numa área no norte da Argentina rica em carrapatos e hospedeiros, durante seis viagens de campo conduzidas em 1999 (janeiro e agosto), 2000 (março e novembro) e 2001 (março e junho). Os carrapatos foram identificados como Amblyomma cajennense (Fabricius), A. coelebs Neumann, Amblyomma sp., Haemaphysalis juxtakochi Cooley, H. leporispalustris (Packard), Ixodes pararicinus Keirans & Clifford, I. loricatus Neumann, I. longiscutatum Boero e Ixodes sp. Pequenos mamíferos foram principalmente parasitados por estágios imaturos de Ixodes; humanos e animais domésticos, predominantemente por Amblyomma spp., e pássaros, principalmente por ninfas e larvas de Haemaphysalis spp.

Information on autochthonous ticks and their hosts is scarce in South America, especially in Argentina. To contribute to tick knowledge in the region, 2094 ticks were collected from the vegetation, humans, domestic and wild animals at a host-and-tick rich area of northern Argentina during six field trips conducted in 1999 (January and August), 2000 (March and November), and 2001 (March and June). The ticks were identified as Amblyomma cajennense (Fabricius), Amblyomma coelebs Neumann, Amblyomma sp., Haemaphysalis juxtakochi Cooley, H. leporispalustris (Packard), Ixodes pararicinus Keirans & Clifford, I. loricatus Neumann, I. longiscutatum Boero and Ixodes sp. Small mammals were mainly parasitized by immature stages of Ixodes; humans and domestic animals, predominantly by Amblyomma spp., and birds, mainly by nymphs and larvae of Haemaphysalis spp.