Fertilization of maize with compost from cattle manure supplemented with additional mineral nutrients

[EN] An alternative approach for cattle manure management on intensive livestock farms is the composting process. An industrial-scale composting plant has been set up in northwest Spain for producing compost from cattle manure. Manure composting involved an increase in pH, electrical conductivity (EC), cation exchange capacity (CEC) and NO3--N concentration, and a decrease in temperature, moisture content, organic matter (OM) content, NH4+-N concentration and C/N ratio. Cu, Zn and Ni concentrations increased due to the reduction of pile weight during the composting process. The resulting compost was applied to a field to study the viability of applying this compost combined with a nitrogen mineral fertilizer as a replacement for the mineral fertilization conventionally used for maize (Zea mays L.). The thermophilic phase of the composting process was very prolonged in the time, which may have slowed down the decomposition of the organic matter and reduced the nitrification process, leading to an over-short maturation phase. The humification and respirometric indexes, however, determined immediately after compost application to the soil, showed it to be stable. Compost application did not decrease the grain yield. A year later, soil pH, OM content and CEC were higher with the compost treatment. Total P, K, Ca and Na concentrations in compost-amended plots were higher than in mineral-fertilized ones, and no significant differences between treatments were found in soil concentrations of NH4+-N, NO3--N, available P, Mg and B. Compost caused no heavy metal pollution into the soil. Therefore, this compost would be a good substitute for the mineral fertilizers generally used for basal dressing in maize growingS

Assessing the agronomic and environmental effects of the application of cattle manure compost on soil by multivariate methods

[EN] Multivariate analysis was used for interpreting data from a pot experiment using samples of three Spanish soils. Samples of soil fertilized with compost were compared with untreated control samples. We also compared the effect of adding the compost to soil with a controlled moisture content of 50% of its water holding capacity (WHC), and to a near-saturated soil (95% WHC). Hierarchical cluster analysis (HCA) and principal component analysis (PCA) were used; they perfectly differentiated sample groups both as a function of the treatment applied and by sampling date. The compost samples were characterized by higher pH, electrical conductivity (EC), organic matter (OM) content and cation exchange capacity (CEC), together with nutrient concentrations than the control pots. The pots with a soil–compost mixture at 95% WHC presented lower values of EC, CEC, inorganic N, K, Na and B than the mixtures at 50% WHC. Multivariate methods may therefore be useful for the analysis and interpretation of a large number of data in soil researchS

Influencia de procesos de ludificación en entornos de aprendizaje STEM para alumnos de Educación Superior = Influence of Gamification Processes in STEM Learning Environments for Higher Education Students

P. 35-68Los alumnos de ciencias, tecnología e ingeniería, en el ámbito del Espacio Europeo de Educación Superior, suelen abordar sus asignaturas como parcelas de conocimiento debido a la propia construcción de los planes docentes y la estructura interdepartamental de las universidades. es decir, sin que se profundice en la interrelación entre esas parcelas y la futura realidad laboral que el estudiante tendrá que vivir. Durante esta investigación se diseñó un juego de mesa, desde el marco de referencia de educación STEAM, con la finalidad de establecer dinámicas propias de las actividades lúdicas para generar un entorno de aprendizaje ludificado. Mediante un proceso de investigación planificado, organizado, dirigido y sistemático se valoró el efecto que tiene la utilización del juego de mesa sobre las calificaciones académicas del alumnado de ingeniería, partiendo de la hipótesis de que la utilización de este juego permite adquirir no solo conocimientos, sino también la capacidad de integrar los conocimientos de las asignaturas directamente vinculadas al entorno STEAM. El análisis de los resultados verificó la hipótesis de partida de esta investigación, confirmando el efecto positivo que tiene el uso de elementos de ludificación en entornos STEAM.S

Combustion of avocado crop residues: varieties and nature of nutrients influence

The thermal behaviour of avocado crop residues was studied. The seeds and the pruning remains from Hass and Bacon varieties were analysed to know their fuel properties. The influence of the fertiliser nature was also studied thorough the application of cow manure and inorganic products. Thermogravimetric analysis (TGA) was carried out under 10, 20 and 40 ºC/min heating rates. Kinetics was also estimated according to the Friedman, Flynn-Wall-Ozawa (FWO) and Kissinger- Akahira-Sunose (KAS) methods. Results indicated the good fuel performance of the samples. Higher heating values (HHV) were higher for pruning remains (19.43 MJ/kg) when compared to seeds (18.74 MJ/kg). Cow manure improved the behaviour of all avocado samples regardless of the varieties. Average action energy was lower for wood (143.89 – 211.04 kJ/mol) than seeds (174.05 - 279.99 kJ/mol). Regarding TGA, this analysis showed three different mass loss associated to hemicellulose, cellulose and lignin release. TGA profiles were so different for the different biomass sources according to the fertiliser employed. Hence, the heating rate influenced the thermal behaviour of the samples, highlighting the fast release of the SBC and WHM for the 10 and 20ºC/min ramps respectivelySIF. Lima investigation was conducted within the framework of a predoctoral contract (A.2) under the I Research and Transfer Plan of the University of Málag

Del aula universitaria a la industria en un clic de móvil

Mención honorífica 2018[ES] La experiencia propuesta quiere suplir el gran salto que experimenta el alumnado de ingeniería cuando abandona la Universidad y se enfrenta al “mundo industrial”. De esta manera, la propuesta surge como respuesta a la queja recurrente de nuestros alumnos egresados al percibir un salto procedimental muy importante entre la práctica operativa aprendida en la Universidad y la práctica operativa real existente en el ámbito industrial

Galilei, un novedoso y divertido juego de mesa para estudiantes de Ciencias, Ingeniería y Tecnología (asignaturas de ámbito STEM)

Premio a la Innovación en la Enseñanza 2021[ES] Desde el grupo de innovación docente de la Universidad de León denominado DINBIO (Docencia en Ingeniería de Biosistemas) se impulsó la experiencia innovadora presentada en esta propuesta. La experiencia innovadora surge ante la carencia y demanda por parte del alumnado de ciencias, ingeniería y tecnología (asignaturas STEM) de juegos específicos para su entorno de aprendizaje. Aunque son muchos los juegos de mesa basados en formato pregunta/repuesta, prácticamente no existe, hasta la fecha, ninguno que responda al domino propio de las asignaturas STEM y que, a su vez, permita la integración de conocimientos propios de estas asignaturas, aspecto fundamental a la hora de valorar la capacidad laboral del alumnado STEM. De esta manera, el recurso académico presentado cubre no sólo un vacío académico existente en nuestro entorno docente, sino un nicho de mercado de gran potencialidad. Una de las grandes novedades que presenta el juego es que la respuesta a las diferentes situaciones tecnológicas o científicas planteadas durante la utilización del mismo es abierta, esto es, será diferente para cada jugador (la respuesta que permite al jugador avanzar a lo largo del tablero no es siempre la misma, sino que será diferente en función de la situación del jugador en ese momento y en esa partida); esta característica hace del juego un material para cualquier entorno académico (bachillerato y universitario) relacionado con asignaturas STEM

Un plan innovador de recogida y tratamiento de la información para mejorar el rendimiento académico

Sección: Educando en lo nuestro[ES] La recogida y posterior tratamiento de la información que el alumno recaba en el aula es un aspecto fundamental para el éxito del estudio personal. Dentro del Grupo de Innovación Docente DINBIO de la Universidad de León se ha detectado un bajo nivel de éxito en la asignatura de Bases de Ingeniería dentro del segundo curso de los estudios de Grado en Biotecnología. Se abordó la problemática en el rendimiento desde la mejora de la toma de apuntes y su posterior utilización en el estudio personal realizando una intervención en el aula y fuera del mismo, en el cual se utilizan adaptaciones del Método Cornell de toma de apuntes. Tras su aplicación se observó una mejora significativa en el alumnado de más bajas calificaciones y una homogeneización de las calificaciones

Effect of Applying Organic Amendments on the Pyrolytic Behavior of a Poplar Energy Crop

Thermal conversion of biomass derived from energy crops is one alternative for the production of energy. In this work, thermogravimetric analysis of poplar biomass was carried out and both the kinetic parameters (activation energy and frequency factor) and characteristic indexes were determined. Four poplar clones (UNAL, I-214, AF-2 and AF-8) under no fertilization (CONTROL) or under fertilization with either dehydrated composted sewage sludge (BIOSOLIDS) or sludge from dairy wastewater treatment (MUD) were used in this work. Five weight loss stages were identified in the DTG pyrolysis curves: moisture loss, active pyrolysis (two phases), passive pyrolysis and a high-rank pyrolysis phase. Among them, the second pyrolysis active phase was the most representative one. For this stage, BIOSOLIDS-UNAL poplars biomass was the one that achieved the highest weight loss values. The characteristic parameters and indexes (especially P and Pi indexes) also pointed to UNAL poplars under BIOSOLIDS fertilization as the most favourable for pyrolytic thermal conversion.SIAuthors would like to thank funding given by the Junta de Castilla y León (Project LE129A11). Also, Sergio Paniagua and Carla Escapa are grateful to the Spanish Ministry of Education, Culture and Sports for their PhD fellowships (FPU14/05846 and FPU12/03073, respectively)

Study of quinoa plant residues as a way to produce energy through thermogravimetric analysis and indexes estimation

Quinoa is a pseudo-cereal employed to provide nutrition and sustenance for a long time. Currently, the consumption of seeds of this plant is increasing. The seed are the only nutritionally part, which implies that both the husks like the rest of biomass represent a residue vaguely studied. Authors had studied the thermal behavior of these quinoa inedible parts. Fuel properties, biomass composition and DTG profiles were done for an oxidative atmosphere under different heating rates in the same way that several characteristic combustion indexes were estimated. Also, DTG profiles for a non-oxidative environment together with the characterization of the char obtained were showed. Results denoted that quinoa biomass presented a more suitable nature for combustion process compared with the husks. Furthermore, combustion DTG profiles showed two different stages: devolatilization and ignition. The maximum combustion weight loss value (20.63 %/min) was achieved for biomass under a 40 K/min rate. DTG profiles under inert atmosphere evidenced two weight loss stages clearly influenced by the cellulose and lignin content. Once again, biomass was the one with the better behavior instead of the husk for this pyrolysis process. Biomass which had good values in terms of yield (26.02 %) and heating value (15.41 MJ/kg).S

Pyrolysis technology for Cortaderia selloana invasive species. Prospects in the biomass energy sector

Cortaderia selloana (CS), is an invasive and exotic species that is generating significant invasive problems in the Iberian Peninsula ecosystems. The objective of this research was to study this plant potential thorough a pyrolytic process helping to reduce its expansion. Stems and leaves were subjected to conventional and flash pyrolysis. These processes were carried out in an original design oven using a 25°C/min heating ramp at a 750°C temperature and during 60 min at the pyrolysis temperature for conventional pyrolysis and with 750°C and 850°C pyrolysis temperatures for flash. Gas-fraction obtained by flash pyrolysis had higher HHV data when compared with conventional ones (~17 MJ/kg vs ~ 5 MJ/kg) due to their less CO2 and higher CO, CH4 and H2. The greater bio-oil yield was obtained for CSS-P (33.58%). The composition of conventional pyrolysis bio-oils had an overbearing of nonaromatic and monoaromatic hydrocarbons nature whereas bio-oils from flash pyrolysis were composed mainly of polycyclic aromatic hydrocarbons. Bio-char fraction was higher in CSL than CSS with HHV similar to lignite and bituminous coals (22.74 to 29.12 MJ/kg). After done the quantification and characterization of the fractions, it was concluded that a possible energetic valorization of Cortaderia selloana biomass was possible