Desarrollo de trazadores de suelo para el estudio del arrastre y redistribución de sedimentos debidos a la erosión hídrica

La erosión hídrica es motivo de preocupación para la sostenibilidad de los sistemas agrícolas en el mundo y especialmente en la cuenca del Mediterráneo. Las limitaciones de los métodos tradicionales de medida de la erosión, han impulsado el uso de trazadores ambientales para proporcionar información adicional y así implementar estrategias de conservación a diferentes escalas. Hay diferentes enfoques para la selección del trazador con respecto a sus propiedades, métodos de aplicación y su detección. Debido a la dificultad para encontrar trazadores que reúnan todos los requisitos definidos por Zhang et al. (2001) y que proporcionen una evaluación fiable de la dinámica de la erosión y los sedimentos, nuevos trazadores aparecen cada año. El objetivo principal de esta tesis es el desarrollo de un trazador simple y barato para su uso en ensayos de erosión hídrica a escala de laboratorio y campo. En una primera etapa, se consideraron dos tipos de trazadores, óxidos de tierras raras (La2O3, Pr6O11, Nd2O3 and Sm2O3) y óxidos de hierro (magnetita Fe3O4, hematites -Fe2O3 y goethita FeOOH). En una etapa posterior de los óxidos de tierras raras se descartaron debido a la complejidad e incertidumbres que intervienen en su determinación analítica, además del alto coste de su adquisición y análisis En el Capítulo 1 se examinan los métodos de trazado existentes, adoptados en experimentos de erosión, distinguiendo entre ellos los radionúclidos, tierras raras, ‘fingerprinting’, y los óxidos magnéticos. Además, se describen y comparan los diferentes métodos, discutiendo las ventajas y desventajas de cada uno de ellos. El Capítulo 2 describe los ensayos de laboratorio y las simulaciones de lluvia diseñados para comprender el comportamiento y el potencial de magnetita como un trazador de sedimento en cuatro suelos mediterráneos de distinta clase textural. Los dos capítulos siguientes están dedicados a la exploración de los óxidos de hierro como trazadores erosión bajo lluvia simulada y natural para entender el movimiento del suelo debido a la erosión hídrica. El Capítulo 3, analiza la dinámica de la erosión en un sistema de surcos-lomos cultivado con algodón, en simulaciones de lluvia a pequeña escala utilizando magnetita y a escala de ladera combinando magnetita, hematita y goethita durante una prueba de riego por aspersión. Se utilizó también un modelo de erosión para entender y extrapolar la dinámica de la erosión hídrica en los sistemas agrícolas bajo diferentes escenarios. En el Capítulo 4 el procedimiento del marcado del suelo con óxido de hierro magnético, fue puesto a punto en unas parcelas de olivar, combinando medidas de susceptibilidad magnética en laboratorio y campo. La variación del contenido de magnetita se utilizó para estimar la contribución, de cada zona dentro de las parcelas, a las pérdidas totales de suelo causadas por las precipitaciones naturales y la redistribución del suelo después del labrado. Finalmente, el Capítulo 5 es un debate general sobre el trabajo, incluyendo en él las conclusiones más relevantes. Aunque el uso de óxido de hierro magnético implica algunas limitaciones, tales como la dificultad de conseguir un marcado uniforme del perfil del suelo, es posible cuantificar la contribución de las diferentes fuentes o áreas de deposición de sedimentos bajo diferentes manejos de suelo y cultivos. Por lo tanto, los trazadores basados en óxidos de hierro constituyen una herramienta útil y complementaria a las medidas tradicionales de pérdidas de suelo en los procesos de erosión.Water erosion is a matter of concern for the sustainability of agricultural systems in the world, and especially in the Mediterranean basin. The limitations of the traditional erosion measurement methods have prompted the use of environmental tracers to provide additional information for implementing conservation strategies at different scales. There are different approaches to the tracer selection with respect to their properties, methods of application and their detection. Given the difficulties found in the use of tracers to fulfil all the requirements for a reliable assessment of the erosion and sediment dynamics defined by Zhang et al. (2001), new tracers are appearing every year. The main objective of this dissertation is the development of a simple and cheap tracer for its use in field and laboratory water erosion experiments. In a preliminary stage, two sets of tracers were considered; rare earth oxides (La2O3, Pr6O11, Nd2O3 and Sm2O3) and iron oxides (magnetite Fe3O4, hematite -Fe2O3 and goethite FeOOH). In a subsequent stage, the rare earth oxides were discarded due to the complexity and uncertainties involved in their analytical determination, in addition to their high acquisition and analysis costs. Chapter 1 reviews the existing tracer methods adopted in erosion experiments, distinguishing between them radionuclides, rare earths, fingerprinting, and magnetic oxides. The methods are also described and compared and their advantages and disadvantages are discussed. Chapter 2 describes the laboratory tests designed and rainfall simulation experiments to understand the behaviour and potential of magnetite as a sediment tracer in four Mediterranean soils of a varied textural class. The next two Chapters are devoted to the exploration of iron oxides as erosion tracers. They were used at hillslope scale under simulated and natural rainfall to understand soil movement by water erosion. Chapter 3, analyses the erosion dynamics in a cotton crop plot planted in a furrowbed system under rainfall simulations at a small scale using magnetite, and at a hillslope scale by the combination of magnetite, hematite and goethite during a sprinkler irrigation test. An erosion model was also used to understand and extrapolate the dynamics of water erosion in agricultural systems under different scenarios. In Chapter 4 the sediment tracking procedure using magnetic iron oxide was set up in olive orchard plots combining laboratory and field magnetic susceptibility measurements. The variation in magnetite content was used to estimate the contribution of each area within the plots to total soil losses caused by natural rainfall events and the soil redistribution after tillage. Finally, Chapter 5 is a general discussion on the work including the most relevant conclusions in it. Although the use of magnetic iron oxides implies some limitations such as, the difficulty of obtaining a uniform tagging of soil profile, it is possible to quantify the contribution of the different sources or deposition areas of sediment under different soil managements and crops. Therefore, the tracers based on iron oxides constitute a useful tool, which is complementary to traditional soil loss measurements of erosion processes

Control simultáneo y medidas correctivas en la Notaria Cuarta de Babahoyo - Provincia de Los Ríos - Ecuador

En el estudio realizado se planteó el siguiente objetivo general que es determinar la relación que existe entre el Control simultáneo y medidas correctivas en la Notaria Cuarta de Babahoyo - Provincia de Los Ríos – Ecuador. Esta investigación tiene un enfoque cuantitativo de tipo transversal descriptiva correlacional, con un diseño no experimental. Se obtuvo una muestra de 50 usuarios, teniendo como instrumento de aplicación un cuestionario el cual constó de 40 ítems este tuvo un resultado de confiabilidad de 0.95, concluyendo así que el Control simultáneo y medidas correctivas se conserva con un nivel de medio o regular dentro de todas funciones en cada una de las áreas de trabajo; finalmente podemos concluir que es necesario incorporar estrategias de capacitaciones en todas las dimensiones de las variables en estudio, además se debe implementar personal calificado para evaluar los perfiles de cada trabajador, esto ayudará a mejorar el Control simultáneo y medidas correctivas en la Notaria Cuarta de Babahoyo - Provincia de Los Ríos – Ecuador aumentando satisfactoriamente

Catch-C

El fin principal del Proyecto Catch-C es evaluar la compatibilidad en diferentes explotaciones agroganaderas de prácticas de manejo sostenibles analizando las dificultades, sinergias y ventajas, entre el incremento de la productividad, la mitigación de los efectos del cambio climático y la conservación de la calidad química, física y biológica del suelo. Estos resultados sobre buenas prácticas de manejo y su viabilidad en diferentes tipos de explotaciones y ambientes crearán una conciencia sobre las ventajas e inconvenientes de distintas opciones de manejo y de políticas agrarias

Validación de un cuestionario para el análisis del comportamiento y actuación de los padres y madres en el deporte (ACAPMD)

Sport in schools is, often, a reflection of professional sport that currently takes place in our society, when it is assumed that most children choose sports as mostly or enjoy being with friends. Thus, we consider it important to know the opinion that parents have about sports in school age that their children practice. The objective of the present study was to design and validate a questionnaire for parents in order to know what their perceptions, behaviors and attitudes regarding the sport of their children, concretely in the Municipal Sports Academies in Sevilla. For this reason, this article shows the construction and validation of a questionnaire in different phases: the validation of the questionnaire through the experts, the draft of the definitive questionnaire and the pilot study and the record of the information for the process of reliability.El deporte en el ámbito escolar, en muchas ocasiones es un reflejo del deporte rendimiento o federado que se da actualmente en la sociedad, cuando se supone que la mayoría de los niños principalmente escoge el deporte como disfrute o por estar con los amigos. Por ello, consideramos importante conocer la opinión que tiene los padres y madres acerca del deporte en edad escolar que practican sus hijos. El objeto del presente estudio es diseñar y validar un cuestionario para padres y madres con el fin de conocer sus actitudes e implicaciones en el deporte de sus hijos, concretamente en las Escuelas Deportivas Municipales de Sevilla.Por esta razón en el presente artículo se muestra la construcción y validación de un cuestionario a través de diferentes fases: la validación del cuestionario por parte de expertos, la redacción del cuestionario definitivo y el estudio piloto y el registro de los datos para el proceso de fiabilidad

Motivational analysis of tourists who visit a city with inscriptions World Heritage Site, Granada, Spain

In recent times, it has been noticed that cultural tourism attracts millions of people. One interesting aspect is the analysis of WHS (World Heritage Site) destinations or cultural destinations that have an inscription WHS. This research has the goal of analysing the different groups of tourists who visit a cultural destination with an inscription WHS, specifically the city of Granada (Spain). For this, segmentation was performed, studying the socio-demographic profile of the tourists and their assessment of the attributes of this destination. For the tourist segmentation, two models have been followed. Four different groups of tourists were found: alternative, cultural, emotional and heritage. In this last one, the relationship between curiosity about the culture of the tourist destination and the heritage visited has a determining role. This study makes an important contribution to the literature regarding the links between the tourist and the historic and monumental heritage they visit and their tourist behaviour

Determination of agro-environmental zones in Spain and sensitivity to global climatic change

Póster presentado en la Conferencia EGU 2013, 07-12 Abril 2013, Viena, AustriaSoil has a key role in the regulation of carbon, water and nutrient cycles. Traditionally, agricultural soil management was oriented towards optimizing productivity. Nowadays, mitigation of climate change effects and maintaining long-term soil quality are evenly important. Developing policy guidelines for best management practices need to be site-specific, given the large spatial variability of environmental conditions within the EU. Therefore, it is necessary to classify the different farming zones that are susceptible to soil degradation. Especially in Mediterranean areas, this variability and its susceptibility to degradation is higher than in other areas of the EU. The objective of this study is therefore to delineate current agro-environmental zones in Spain and to determine the effect of global climate change on this classification in the future. The final objective is to assist policy makers in scenario analysis with respect to soil conservation. Our classification scheme is based on soil, topography and climate (seasonal temperature and rainfall) variables. We calculated slope and elevation based on a SRTM-derived DEM, soil texture was extracted from the European Soil Database and seasonal mean, minimum and maximum precipitation and temperature data were gridded from publically available weather station data (Aemet). Global change scenarios are average downscaled ensemble predictions for the emission scenarios A2 and B2. The k-means method was used for classification of the 10 km x 10 km gridded variables. Using the before-mentioned input variables, the optimal number of agro-environmental zones we obtained is 8. The classification corresponds well with the observed distribution of farming typologies in Spain. The advantage of this method is that it is a simple, objective method which uses only readily available, public data. As such, its extrapolation to other countries of the EU is straightforward. Finally, it presents a tool for policy makers to assess the impact of global change on farming systems and to plan soil conservation measures

Highly efficient system for the micropropagation and acclimatization of pineapple in vitro plants (Ananas comosus L. Merr, var. MD2)

The low acclimatization efficiency of pineapple seedlings obtained by in vitro culture has been one of the main limitations to massively scale micropropagation protocols. Various factors may be affecting the successful establishment of in vitro plants to ex vitro conditions, related to the plant and/or the environment and the management of seedlings. The objective of this study was to establish an efficient micropropagation and acclimatization system for the MD2 variety, with a high in vitro multiplication rate and a high greenhouse and field survival of pineapple in vitro plants. In the multiplication phase, the axillary buds were isolated and placed on a semisolid medium and three induction treatments with different concentrations of BAP (1.0, 3.0, 5.0 mg/L) and ANA (2.0 mg/L), were evaluated. After the third subculture, multiple shoots were transferred to a temporary immersion system (BIOMINT). During acclimatization and nursery phases, six treatments with different substrate compositions wereevaluated. The induction treatment IT3 (BAP 5.0 mg/L and ANA 2.0 mg/L) was selected for a significantly high multiplication rate. AT4 treatment (Soil + Coconut fiber + perlite 1:1:1) showed the highest survival rate (95%) and allowed the obtaining of well-developed plants. This system constitutes a valuable technology to introduce in vitro plants to the pineapple production scheme on a commercial scale

Does tillage influence physical- and chemical- related soil quality indicators equally?

Trabajo presentado en la EGU General Assembly 2019, celebrada en Viena del 3 al 8 de mayo de 2019.Soil degradation is linked with a loss of land′s actual or potential productivity. This process is a result of naturaland anthropogenic action being soil tillage one of the main drivers of the last. As a result, soil quality, whichmanifests soil′s capacity to produce ecosystem services and goods, can be compromised. There are severalindicators traditionally measured to characterize soil quality, either based on soil physical or chemical properties.Among soil physical properties, water flow features, as expressed through the soil water retention curve, aredirectly linked to the distribution of soil pores and can be useful to derive different indices (such as the S index)to evaluate soil′s quality. Organic matter, nutrients, and cation exchange capacity are also soil chemical propertiesaffecting soil quality.The main aim of this study was to evaluate the methodology based on the S index (Dexter, 2004) andselected soil (chemical and physical) properties at the short term under typical Mediterranean agriculturalconditions. For this reason, physical and chemical soil properties were measured in a short-term trial settle in twoolive orchards under different soil managements: tillage and cover crop and at two depths: surface (0-10 cm) anddepth (10-20 cm). In addition, water retention curves; water storage capacity; and soil porosity were characterized.At the two studied sites, changes in soil management, even after a short period of time, had a quick effectin chemical properties. However, soil′s pore size distribution, as quantified with the S index, did not showremarkable differences after changing soil management. This may be a consequence of the longer-term effectof changing soil management on water retention and transmission. Future research including more soil typesand assessing water-flow-related properties over a longer time interval, may well provide clearer results in theassessment of soil quality.Peer reviewe