Funcionament del pou cisterna de la fortalesa ibera dels Vilars (les Garrigues): evidències de mesures en camp de conductivitat elèctrica de l'aigua en períodes de reg del canal d'Urgell

La fortalesa dels Vilars es caracteritza per la seva fortificació complexa i defensa activa davant del risc de setge o bloqueig en el segle IV aC. El sistema inundable de fossats assegurava el proveïment i la gestió de l'aigua, reforçava la defensa i magnificava l'arquitectura del poder. El funcionament hidrològic del sistema fossat i pou cisterna de l'interior de la fortalesa no pot derivar-se de les condicions geomorfològiques i hidrològiques actuals, pels canvis en el relleu provocats pels anivellaments causats per la posada en reg fa més de cent anys, i, també, pel mateix regatge que ha modificat la dinàmica de la capa freàtica de la zona. Malgrat això, l'existència d'una capa freàtica artificial provocada pel reg permet estudiar la connexió entre les aigües d'escolament del torrent de l'Aixaragall —que suposadament alimentava el fossat— i les del pou cisterna. Mesures de conductivitat elèctrica de l'aigua en els diversos sistemes en tres moments corresponents a dues campanyes de reg (2012 i 2013) suggereixen una connexió entre la capa superficial de l'aqüitard1 format per les calcilutites oligocenes subjacents al fossat, les graves quaternàries que formen el con de dejecció del torrent de l'Aixaragall i el pou. En conseqüència, les mesures preses són compatibles amb l'alimentació del pou a partir del fossat inundat, i amb un origen superficial de l'aigua que devia omplir-lo procedent del torrent de l'Aixaragall.The 4th c. BCE fortress of Els Vilars is marked by its complex fortification and its conception of active defence against the risk of siege or blockade. Its system of floodable moats assured its water supply and management strengthened its defence and accentuated its architecture of power. The hydrological operation of the exterior moat-interior cistern well system could not be elucidated on the basis of today’s geomorphological and hydrological conditions because of the levelling of the surrounding topography since the advent of its irrigation over 100 years ago and because irrigation itself has changed the dynamics of the area’s water table. Despite this, the existence of an artificial water table produced by irrigation allows the study of the connection between the water runoff from the Aixaragall torrent, which supposedly fed the moat, and the water in the cistern well. Electrical conductivity measurements of the water in the various systems at three different moments in the course of two irrigation campaigns (2012 and 2013) suggest a connection between the surface layer of the aquitard formed by Oligocene calcilutites underlying the moat, the Quaternary gravels of the Aixaragall torrent’s alluvial fan and the cistern well. Consequently, the measurements recorded are consistent with the supply of the well from the flooded moat and with the supply of the moat by surface water from the Aixaragall torrent.La fortaleza de Els Vilars se caracteriza por su fortificación compleja y defensa activa frente al riesgo de asedio o bloqueo en el siglo IV aC. El sistema inundable de los fosos aseguraba el abastecimiento y la gestión del agua, reforzaba la defensa y magnificaba la arquitectura del poder. El funcionamiento hidrológico del sistema foso y pozo cisterna del interior de la fortaleza no puede derivarse de las condiciones geomorfológicas e hidrológicas actuales, debido a los cambios en el relieve provocados por nivelaciones causadas por la puesta en riego hace más de cien años, y al propio riego que ha modificado la dinámica de la capa freática de la zona. A pesar de ello, la existencia de una capa freática provocada por riego permite estudiar la conexión entre las aguas de escorrentía del torrente del Aixaragall —que supuestamente alimentaba el foso— y las del pozo cisterna. Medidas de conductividad eléctrica del agua en los diversos sistemas en tres momentos correspondientes a dos campañas de riego (2012 y 2013) sugieren una conexión entre la capa superficial del acuitardo2 formado por las calcilutitas oligocenas subyacentes en el foso, las gravas cuaternarias que forman el cono de deyección del torrente del Aixaragall y el pozo. En consecuencia, las medidas tomadas son compatibles con la alimentación del pozo a partir del foso inundado, y con un origen superficial del agua que debía llenarlo a partir del torrente del Aixaragall

Variáveis edáficas que condicionam o habitat de ácaros oribatídeos em Phaeozems Lúvicos sob plantações florestais (Buenos Aires, Argentina)

The soil is a complex three-dimensional habitat and any changes in its structure and porosity are likely to affect the type and abundance of soil biota. Oribatid mites play an important role in the decomposition and mineralization of soil organic matter and their abundance depends on diverse soil parameters, including soil texture, organic matter content, pH, moisture, and the pore system. The aim of the present work is to analyze some of the edaphic variables that condition the habitat of oribatid mites in Luvic Phaeozems under Pinus radiata (site P) and Eucalyptus globulus (site E) plantations, in the Southeast of Buenos Aires, Argentina. Bulk density, penetration resistance, pH, moisture, pore system parameters, and oribatid abundance and species composition were analyzed. Site E had a greater total porosity than site P. The high tortuosity of the pores in both sites generates a complex habitat architecture for the development of oribatid mites. In both sites, oribatids of 70-400 μm in size predominated and were more abundant in site E. A positive correlation between the abundance of oribatids and the pore size in both sites was observed. In site E this correlation was lower for 70-600 µm (R = 0.13) or negative for 70-400 µm (R = -0.78). Therefore, the oribatid abundance could be explained by a greater complexity of the structure of the organic horizon, lower bulk density and lower penetration resistance. These conditions favor the mineralization of organic matter, and therefore food availability. On the other hand, in site P, oribatid abundance is mainly influenced by the porous system, which conditions the access to food, competition between organisms and refuge from predators. Two new species were registered for Argentina: Mesotritia elegantula and Acrogalumna longipluma.El suelo es un hábitat tridimensional altamente complejo. Los cambios en su estructura y porosidad pueden afectar el tipo y la abundancia de la biota del suelo. Los ácaros oribátidos juegan un papel fundamental en la descomposición y mineralización de la materia orgánica del suelo, y su abundancia depende de la textura, la materia orgánica, el pH, la humedad, el sistema poroso, entre otros. El objetivo del presente trabajo es analizar algunas de las variables edáficas que condicionan el hábitat de los ácaros oribátidos en Phaeozems Lúvicos bajo plantaciones de Pinus radiata(P) y Eucalyptus globulus (E), en el sudeste de la provincia de Buenos Aires, Argentina. Se analizaron la densidad aparente, la resistencia a la penetración, el pH, la humedad, los parámetros del sistema poroso y la abundancia de oribátidos. Ambos sitios presentaron suelos bien estructurados con propiedades edáficas similares. La porosidad total fue mayor en el sitio E con respecto al sitio P. En ambos sitios la tortuosidad de los poros fue alta, lo que genera un hábitat de arquitectura compleja para el desarrollo de los ácaros oribátidos. Tanto en el sitio E como en el P predominaron oribátidos de 70-400 μm de tamaño y, en general, fueron más abundantes en el sitio E. Se observó una correlación positiva entre la abundancia de oribátidos y el tamaño de poros en ambos sitios. En el sitio E, esta correlación fue menor (70-600 μm) o negativa (70-400 μm). Por lo tanto, la abundancia de oribátidos podría explicarse por una mayor complejidad de la estructura del horizonte orgánico, menor densidad aparente y menor resistencia a la penetración. Estas condiciones favorecen la mineralización de la materia orgánica y, por lo tanto, la disponibilidad de alimento. Mientras, en el sitio P, la abundancia de oribátidos está influenciada principalmente por el sistema poroso, que condiciona el acceso al alimento, la competencia entre organismos y el refugio ante predadores. Se registration dos nuevas especies en Argentina, Mesotritia elegantula y Acrogalumna longipluma.O solo é um habitat tridimensional altamente complexo. As mudanças na estrutura e na porosidade podem afetar o tipo e quantidade da biota do solo. Os ácaros oribatídeos têm um papel fundamental na decomposição e mineralização da matéria orgânica do solo, e a sua abundância depende da textura, teor de matéria orgânica, pH, humidade, sistema poroso, entre outros parâmetros do solo. O objetivo do presente trabalho é analisar algumas das variáveis edáficas que condicionam o habitat dos ácaros oribatídeos em Phaeozems Luvicos com plantações de Pinus radiata (P) e Eucalyptus globulus (E) no sudeste da província de Buenos Aires, Argentina. Foram analisados no solo a ddensidade aparente, resistência à penetração, pH, humidade, parâmetros do sistema poroso e a abundancia e espécies dos ácaros oribatídeos. Ambos os sítios apresentaram solos bem estruturados e com propriedades edáficas semelhantes. A porosidade total foi maior no sítio E quando comparado com o sítio P. Em ambos os sítios a tortuosidade dos poros foi alta, o que propicia um habitat de arquitetura complexa para o desenvolvimento dos ácaros oribatídeos. Tanto em E como em P, predominaram ácaros oribatídeos com 70-400 μm de tamanho e, em geral, foram mais abundantes em E. Foi observada uma correlação positiva entre a abundância de oribatídeos e o tamanho dos poros em ambos os sítios. Em E, esta correlação foi menor (70-600 μm) ou negativa (70-400 μm). Portanto, a abundância de oribatídeos poderia ser explicada pela maior complexidade da estrutura do horizonte orgânico, menor densidade do solo e menor resistência à penetração. Estas condições favorecem a mineralização da matéria orgânica e, consequentemente, a disponibilidade de alimento. Por outro lado, em P a abundância de oribatídeos é principalmente influenciada pelo sistema poroso que condiciona o acesso a alimento, a competição entre organismos e refúgio de predadores. Registaram-se duas novas espécies na Argentina, Mesotritia elegantula y Acrogalumna longipluma

Challenge-based learning and the Barcelona ZeroG Challenge: A space education case study

Challenge-Based Learining is a STEM Education methodology that has been used as a collaborative and hands-on approach to encourage students to put their knowledge in practice by addressing real-life problems. Space Education is a field particularly suited to apply it, with hands-on research projects which require students to take actions and communicate their efforts in a multicultural, international scenario in order to produce an optimal response a specific goal. We herein present a successful Challenge-Based Learning Case Study which involves designing, implementing, and actually flying a microgravity experiment in parabolic flight. The Barcelona ZeroG Challenge is an international competition addressed to University students worldwide. It challenges students to build a team with a mentor, propose, design, build and fly their experiment in microgravity and finally communicate their findings. The experiment has to meet the requirements of a unique microgravity research platform available in Barcelona for educational and research purposes. More than fifty students have flown their experiments on board an aerobatic CAP10B aircraft in Barcelona in previous educational campaigns; having published their results in relevant symposiums and scientific journals. These campaigns have always attracted media attention. The current edition is underway with the winner team expected to fly their experiment before the end of 2022. This edition is jointly organized by Universitat Politècnica de Catalunya, the Barcelona-Sabadell Aviation Club and the Space Generation Advisory Council. Up to fifteen projects have been submitted to this edition, an unprecedent number so far. A panel of experts from the European Space Agency Academy conducted the selection of the winner team, who receives a 2500 euros grant to develop its experiment, aside from the opportunity to fly it in parabolic flight. Furthermore, students from our own University have also the opportunity of designing and testing their microgravity experiments during their studies. Principles of Challenge-Based Learning are herein described as well as how this methodology is applied to this Case Study. Results from our experience are very satisfactory as most of the students who have been involved in it perceive this experience as a boost for their careers. Three key factors to success have been identified: a strong involvement from students' associations, a need for international cooperation and the quality of the students’ mentoring. The experience can be of interest for other organizations to conduct a successful CBL educational projec

Challenge-based learning and the Barcelona ZeroG Challenge: a space education case study

Challenge-Based Learining is a STEM Education methodology that has been used as a collaborative and hands-on approach to encourage students to put their knowledge in practice by addressing real-life problems. Space Education is a field particularly suited to apply it, with hands-on research projects which require students to take actions and communicate their efforts in a multicultural, international scenario in order to produce an optimal response a specific goal. We herein present a successful Challenge-Based Learning Case Study which involves designing, implementing, and actually flying a microgravity experiment in parabolic flight. The Barcelona ZeroG Challenge is an international competition addressed to University students worldwide. It challenges students to build a team with a mentor, propose, design, build and fly their experiment in microgravity and finally communicate their findings. The experiment has to meet the requirements of a unique microgravity research platform available in Barcelona for educational and research purposes. More than fifty students have flown their experiments on board an aerobatic CAP10B aircraft in Barcelona in previous educational campaigns; having published their results in relevant symposiums and scientific journals. These campaigns have always attracted media attention. The current edition is underway with the winner team expected to fly their experiment before the end of 2022. This edition is jointly organized by Universitat Politècnica de Catalunya, the Barcelona-Sabadell Aviation Club and the Space Generation Advisory Council. Up to fifteen projects have been submitted to this edition, an unprecedent number so far. A panel of experts from the European Space Agency Academy conducted the selection of the winner team, who receives a 2500 euros grant to develop its experiment, aside from the opportunity to fly it in parabolic flight. Furthermore, students from our own University have also the opportunity of designing and testing their microgravity experiments during their studies. Principles of Challenge-Based Learning are herein described as well as how this methodology is applied to this Case Study. Results from our experience are very satisfactory as most of the students who have been involved in it perceive this experience as a boost for their careers. Three key factors to success have been identified: a strong involvement from students' associations, a need for international cooperation and the quality of the students’ mentoring. The experience can be of interest for other organizations to conduct a successful CBL educational project.Objectius de Desenvolupament Sostenible::4 - Educació de QualitatObjectius de Desenvolupament Sostenible::4 - Educació de Qualitat::4.3 - Per a 2030, assegurar l’accés en condicions d’igualtat per a tots els homes i dones a una formació tècnica, professional i superior de qualitat, inclòs l’ensenyament universitariObjectius de Desenvolupament Sostenible::4 - Educació de Qualitat::4.5 - Per a 2030, eliminar les disparitats de gènere en l’educació i garantir l’accés en condicions d’igualtat a les persones vulnerables, incloses les persones amb discapacitat, els pobles indígenes i els nens i nenes en situacions de vulnerabilitat, a tots els nivells de l’ensenyament i la formació professionalPostprint (published version

Cambios en la porosidad del suelo asociados a la fertilización con purín porcino

En zonas de secano del Valle del Ebro (España), la siembra directa y el uso de deyecciones ganaderas resultan interesantes para reducir costes. Este trabajo tiene como objetivo evaluar, bajo siembra directa de cereal de invierno, el efecto de la fertilización con purines porcinos en la porosidad del horizonte superficial de un suelo de textura franco-limosa. Se establecieron seis dosis de purín, además de un control. El suelo se clasificó como Xerofluvent típico. La porosidad del suelo, sin alterar su estructura, se estudió mediante técnicas micromorfológicas. Los muestreos se realizaron en mayo. Se obtuvieron 21 muestras inalteradas de suelo (0-0,06 m de profundidad) que fueron tratadas hasta obtener láminas delgadas de 5 cm de alto, 13 cm de largo y 30 μm de grosor de las que se fotografiaron dos campos (3,15 cm × 4,2 cm). Los poros se estudiaron mediante análisis de imagen, clasificándose en diferentes intervalos de diámetros aparentes (DA), desde 15 μm hasta 400 μm. Se estableció una relación cuadrática significativa entre la cantidad de N aportada y el porcentaje de poros en los DA entre 200 μm y 400 μm (de 3,4 % a 5,2 % de porosidad total). A pesar de la detección de compactación y de la presencia de una estructura laminar, estos cambios en la porosidad responden a una mejora de la estructura, que podría deberse al hecho de facilitar la actividad de la macrofauna. Esta mejora estructural no se observa en aportaciones de purines inferiores a 100 kg N·ha–1 ni en las aportaciones más altas, próximas a 300 kg N·ha–1.In dryland Mediterranean areas, the usage of slurries and no-till are encouraged to reduce costs. Implementation of these practices is a challenge since they may make soil susceptible to a reduction in its physical quality (particularly through compaction). This paper aims to evaluate the effect of pig slurry fertilisation on superficial soil porosity when no-tillage is used in silty-loam soil. Winter cereal was fertilised with pig slurry at six rates. There was also a non-nitrogen treatment (control). The soil was classified as a Typic Xerofluvent. Soil porosity was studied within unaltered soil samples with a micromorphological approach. Soil samples were collected in May. From undisturbed soil samples (0-0.06 m depth), twenty-one thin sections (5 cm × 13 cm × 30 μm) were obtained and photographed into two areas of 3.15 cm × 4.20 cm. Pores were studied using image analysis and they were classified at different intervals of apparent pore diameter (APD) from >15 μm up to 400 μm. Photography analysis showed porosity changes at 200-400 μm of APD. In this interval, there was a quadratic relationship between nitrogen rate and percentage of pores (from 3.4 % to 5.2 % of total porosity). Even though the soil was compacted and had a laminar structure, these porosity changes were associated with an improvement of the soil structure. This positive consequence could be caused by the activity of the macrofauna. This effect was only detected when pig slurry was applied at agronomic rates and it was not observed in slurry treatments below 100 kg N·ha–1 nor close to 300 kg N·ha–1.Las autoras de este trabajo agradecen a J.M. Llop su apoyo en los trabajos de campo, así como al Departamento de Acción Climática, Alimentación y Agenda Rural por el mantenimiento de la parcela experimental. Asimismo, se agradece la colaboración del laboratorio de micromorfología de suelos de la Universitat de Lleida por haber facilitado la elaboración de las láminas delgadas. Este estudio ha sido financiado por el Instituto Nacional de Investigación y Tecnología Agraria y Alimentaria – INIA (proyectos RTA2010- 126-C2-01, RTA2013-57-C5-01 y RTA2017-88- C3-03) y por el Ministerio de Economía, Industria y Competitividad

Prospecció geoarqueològica del curs mitjà del Segre (Artesa de Segre, Foradada, Cubells i Alòs de Balaguer, La Noguera)

La prospecció geoarqueològica té com a objectiu la recerca d'assentaments arqueològics mitjançant la informació geomorfològica i edàfica que ens proporciona l'estudi dels dipòsits quaternaris; també permet establir una correlació entre l'evolució del relleu i les ocupacions antròpiques. L'àrea d'aquest estudi és la compresa entre Artesa de Segre i Alòs de Balaguer. Van suscitar la intervenció els treballs que es duen a terme a la cova del Parco (Alòs de Balaguer) a fi de localitzar altres possibles emplaçaments arqueològics i dipòsits quaternaris que complementin les investigacions desenvolupades en aquest indret

Soil: the great connector of our lives now and beyond COVID-19

Humanity depends on the existence of healthy soils, both for the production of food and for ensuring a healthy, biodiverse environment, among other functions. COVID-19 is threatening food availability in many places of the world due to the disruption of food chains, lack of workforce, closed borders and national lockdowns. As a consequence, more emphasis is being placed on local food production, which may lead to more intensive cultivation of vulnerable areas and to soil degradation. In order to increase the resilience of populations facing this pandemic and future global crises, transitioning to a paradigm that relies more heavily on local food production on soils that are carefully tended and protected through sustainable management is necessary. To reach this goal, the Intergovernmental Technical Panel on Soils (ITPS) of the Food and Agriculture Organization of the United Nations (FAO) recommends five active strategies: improved access to land, sound land use planning, sustainable soil management, enhanced research, and investments in education and extension