15 research outputs found

    El papel del nitrógeno en agricultura. Zonas vulnerables al nitrato

    Full text link
    El nitrógeno, cuyo símbolo químico es N, fue descubierto como elemento químico independiente en 1772, por el médico, químico y botánico escocés Daniel Rutherford (1749-1819). El N representa aproximadamente el 78 % del aire atmosférico que respiramos, donde se encuentra mayoritariamente en forma molecular (N2). En la corteza terrestre se encuentra en forma de nitrato sódico (NaNO3, nitrato de Chile), o nitrato potásico (KNO3, salitre). En su forma molecular se comporta como un gas sin color (incoloro) olor (inodoro) ni sabor (insípido) y es muy poco reactivo, lo que le convierte en un gas prácticamente inerte. En la Tabla 1 se muestran los principales compuestos minerales presentes en la Naturaleza que contienen N en su composición química; además de los compuestos minerales indicados en la Tabla 1, el N forma parte de las proteínas, de los ácidos nucleicos (ADN y ARN) y de otras muchas moléculas orgánicas que son indispensables para la vida de las planta

    Responses of reference evapotranspiration to changes in atmospheric humidity and air temperature in Spain

    Get PDF
    We studied the sensitivity of reference evapotranspiration (ETo) to global warming in Spain at the end of the 21st century. The FAO-56 Penman-Monteith equation was used to estimate ETo, and we examined the sensitivity of the latter to changes in temperature and relative humidity. Changes in stomatal resistance in response to increased CO2 concentration were not evaluated, nor were the changes in wind velocity and solar radiation. Different scenarios were used for estimation of future ETo in different river basins as a consequence of trends in the maximum and minimum temperatures and maximum and minimum humidities during the period 1973–2002, as observed from 38 meteorological stations. The temperature increases ranged between 0.3 and 0.7°C decade – 1 , and the relative humidities fluctuated between 0.1 and –3.7% decade – 1 Four scenarios were simulated that . considered the variations in linear tendency of the maximum and minimum temperatures and maximum and minimum relative humidities. The trends of the 4 scenarios were incorporated with the data from 338 agrometeorological stations to estimate future ETo. In all cases, there was an annual increase in ETo of 11, 21, 36 and 7% above the annual ETo (1196 mm) for Scenarios 0, 1, 2 and 3, respectively. The river basin most affected by these changes was the Ebro River valley. The most affected months were May, June, July and August, while the least affected months were November, December and Januar

    Real cases study through computer applications for futures Agricultural Engineers

    Full text link
    One of the huge concerns on the higher engineer education is the lag of real cases study that the future professionals need in the work and corporation market. This concern was reflected in Bologna higher education system including recommendations in this respect. The knowhow as why this or other methodology is one of the keys to resolve this problem. In the last courses given in Department of Crop Production, at the Agronomy Engineer School of Madrid (Escuela Técnica Superior de Ingenieros Agrónomos, UPM) we have developed more than one hundred applications in Microsoft Excel®. Our aim was to show different real scenarios which the future Agronomic Engineers can be found in their professional life and with items related to crop production field. In order to achieve our target, each application in Excel presents a file text in which is explained the theoretical concepts and the objectives, as well as some resources used from Excel syntax. In this way, the student can understand and use of such application, even they can modify and customize it for a real case presented in their context and/or master project. This electronic monograph gives an answer to the need to manage data in several real scenarios showed in lectures, calculus resolution, information analysis and manage worksheets in a professional and student level

    Future reference evapotranspiration in Duero Valley (Spain)

    Get PDF
    The impact of climate change and its relation with evapotranspiration was evaluated in the Duero River Basin (Spain). The study shows the possible future situations 50 years from now from the reference evapotranspiration (ETo). The maximum temperature (Tmax), minimum temperature (Tmin), dew point (Td), wind speed (U) and net radiation (Rn) trends during the 1980-2009 period were obtained and extrapolated with the FAO-56 Penman- Montheith equation to estimate ETo. Changes in stomatal resistance in response to increases in CO2 were also considered. Four scenarios were done, considering the concentration of CO2 and the period analyzed (annual or monthly). The scenarios studied showed the changes in ETo as a consequence of the annual and monthly trends in the variables Tmax, Tmin, Td, U and Rn with current and future CO2 concentrations (372 ppm and 550 ppm). The future ETo showed increases between 118 mm (11%) and 55 mm (5%) with respect to the current situation of the river basin at 1042 mm. The months most affected by climate change are May, June, July, August and September, which also coincide with the maximum water needs of the basin?s crop

    Trends in climatic variables and future reference evapotranspiration in Duero Valley (Spain)

    Get PDF
    The impact of climate change and its relation with evapotranspiration was evaluated in the Duero River Basin (Spain). The study shows possible future situations 50 yr from now from the reference evapotranspiration (ETo). The maximum temperature (Tmax), minimum temperature (Tmin), dew point (Td), wind speed (U) and net radiation (Rn) trends during the 1980–2009 period were obtained and extrapolated with the FAO-56 Penman-Montheith equation to estimate ETo. Changes in stomatal resistance in response to increases in CO2 were also considered. Four scenarios were done, taking the concentration of CO2 and the period analyzed (annual or monthly) into consideration. The scenarios studied showed the changes in ETo as a consequence of the annual and monthly trends in the variables Tmax, Tmin, Td, U and Rn with current and future CO2 concentrations (372 ppm and 550 ppm). The future ETo showed increases between 118 mm (11 %) and 55 mm (5 %) with respect to the current situation of the river basin at 1042 mm. The months most affected by climate change are May, June, July, August and September, which also coincide with the maximum water needs of the basin’s crop

    Survey and brain storming studies about machines, constructions, human and environmental risk consideration in the careers of the Universidad Politécnica of Madrid

    Get PDF
    The Universidad Politécnica of Madrid (UPM) includes schools and faculties that were for engineering degrees, architecture and computer science, that are now in a quick EEES Bolonia Plan metamorphosis getting into degrees, masters and doctorate structures. They are focused towards action in machines, constructions, enterprises, that are subjected to machines, human and environment created risks. These are present in actions such as use loads, wind, snow, waves, flows, earthquakes, forces and effects in machines, vehicles behavior, chemical effects, and other environmental factors including effects of crops, cattle and beasts, forests, and varied essential economic and social disturbances. Emphasis is for authors in this session more about risks of natural origin, such as for hail, winds, snow or waves that are not exactly known a priori, but that are often considered with statistical expected distributions giving extreme values for convenient return periods. These distributions are known from measures in time, statistic of extremes and models about hazard scenarios and about responses of man made constructions or devices. In each engineering field theories were built about hazards scenarios and how to cover for important risks. Engineers must get that the systems they handle, such as vehicles, machines, firms or agro lands or forests, obtain production with enough safety for persons and with decent economic results in spite of risks. For that risks must be considered in planning, in realization and in operation, and safety margins must be taken but at a reasonable cost. That is a small level of risks will often remain, due to limitations in costs or because of due to strange hazards, and maybe they will be covered by insurance in cases such as in transport with cars, ships or aircrafts, in agro for hail, or for fire in houses or in forests. These and other decisions about quality, security for men or about business financial risks are sometimes considered with Decision Theories models, using often tools from Statistics or operational Research. The authors have done and are following field surveys about risk consideration in the careers in UPM, making deep analysis of curricula taking into account the new structures of degrees in the EEES Bolonia Plan, and they have considered the risk structures offered by diverse schools of Decision theories. That gives an aspect of the needs and uses, and recommendations about improving in the teaching about risk, that may include special subjects especially oriented for each career, school or faculty, so as to be recommended to be included into the curricula, including an elaboration and presentation format using a multi-criteria decision model

    Modelo de desarrollo de Competencias en Gestión de Riesgos Ambientales (COGRA)

    Get PDF
    La gestión de riesgos medioambientales requiere integrar diversas competencias sobre aspectos económicos, sociales y económicos. Es importante permitir la colaboración entre diferentes. Después de revisar la teoría sobre desarrollo de competencias, observamos que es necesario un estilo de aprendizaje basado las habilidades interpersonales que facilitan la colaboración

    Mathematical modeling in soil science

    Get PDF
    Teaching in context can be defined as teaching a mathematical idea or process by using a problem, situation, or data to enhance the teaching and learning process. The same problem or situation may be used many times, at different mathematical levels to teach different objectives

    Modelo de desarrollo de Competencias en Gestión de Riesgos Ambientales (COGRA)

    Full text link
    La gestión de riesgos medioambientales requiere integrar diversas competencias sobre aspectos económicos, sociales y económicos. Es importante permitir la colaboración entre diferentes. Después de revisar la teoría sobre desarrollo de competencias, observamos que es necesario un estilo de aprendizaje basado las habilidades interpersonales que facilitan la colaboración

    Estilo cognitivo hacia la innovación de los estudiantes: un estudio piloto en la ETSIDI-UPM

    Full text link
    (SPA)Realizamos un estudio de los estilos cognitivos de nuestros estudiantes para entender su forma de innovar y colaborar para alcanzar dicha innovación. Para ello, primero, resumimos el inventario de la Teoría de Kirton Adaptador- Innovador (KM), y segundo, se lo aplicamos a nuestros estudiantes (más innovador o adaptador) en UPM. Aquí presentamos un estudio piloto llevado a cabo en ETSIDI (Escuela Técnica Superior Ingeniería y Diseño Industrial). (ENG)We study of the cognitive styles of our students to understand their process of collaboration and innovation. First, we summarize the inventory of the Kirton's adaptor-innovator Theory (KM), and second, we apply our test, to our students at UPM. In this work, we present a pilot study carried out at ETSIDI (School of Engineering and Industrial Design)
    corecore