ASSESSMENT OF ENERGY CONSUMPTION IN GREENHOUSE PRODUCTION IN THE WEST REGION OF PORTUGAL

Greenhouse production is a very important activity in the West region of Portugal, with an area of approximately 800 ha where the regular production consists in two crops per year, one in winter-spring and the other in summer-autumn. Many growers are now prepared to better exploit market opportunities, since they know that the big export window opportunity is from June to September, when the production is difficult in other regions of south due to high temperatures. Grower’s use new and more productive varieties, either in soil or hydroponic systems, mostly in unheated greenhouses, naturally ventilated, and equipped with modern fertigation systems. Greenhouse production causes some environmental impacts due to the high use of inputs. Several improvements in technologies and crop practices may contribute to increase the use efficiency of resources, decreasing the negative environmental impacts. Greenhouse vegetable production in Northern EU countries is based on the supply of heating and differs significantly from the production system in the Southern EU countries. In the Northern countries, direct energy inputs, mostly for heating, are predominant while in the South the indirect energy input is also important, mainly associated with fertilizers, plastic cover materials and other auxiliary materials. The main objective of this work was to characterise the greenhouse production systems in the West region of Portugal, in order to evaluate the energetic consumptions (direct and indirect), the GHH emissions, the production costs and the farmer’s income. With this work the mostly important inputs were identified, allowing proposing alternative measures to improve efficiency and sustainability. All the data was obtained by surveys performed directly with growers, previously selected to be representative of the crop practices and greenhouse type of the region. However, more research should be performed in order to develop and to test technologies capable to improve resources use efficiency in greenhouse production

Energy consumption and greenhouse gas emissions of zucchini (Cucurbita pepo L.) cultivated in hydroponic greenhouses in the western region of Portugal

In recent years, there has been a significant increase in the consumption of zucchini (Cucurbita pepo L.) in Portugal, which has led to increased production of this vegetable. There is still a deficit of production in winter, but, in summer, production is higher than demand, allowing exportation. At present, there is a positive ratio between zucchini annual exportation/importation values. This means that it is an attractive crop for farmers, especially in the western region of Portugal, which has a microclimate favourable for this crop. The mild winter conditions of the region allow crop growth in unheated greenhouses, which is an advantage for reducing production costs and energy consumption compared with other regions. Crop productivity, either in soil or hydroponics, has increased through the use of better production techniques, modern fertigation systems and new and more productive cultivars. Several improvements in technology and crop practices may now contribute to increased resource-use efficiency, decreasing the negative environmental impact sometimes associated with greenhouse production. The main objective of this work was to evaluate the energy consumption (direct and indirect) and the greenhouse gas (GHG) emissions of greenhouse zucchini produced in the western region of Portugal. All the data were obtained through questionnaires performed directly with growers, which have been previously selected as representative of crop practices and greenhouse type in the region. The results show total energy consumption varying between 4.69 and 6.57 GJ t-1, the electricity used for irrigation making up the largest contribution, followed by the greenhouse material and fertilizers. With this work, the most important inputs were identified, allowing the proposal of alternative measures to improve efficiency and sustainabilit

Evaluation of the SALTMED model for tomato crop production in unheated greenhouses

The SALTMED model is one of the few available generic models that can be used to simulate crop growth with an integrated approach considering water, crop, soil and field management. It is a physically based model using the well-known water and solute transport, evapotranspiration, and water uptake equations. The possibility of using models able to simulate crop growth with this integrated approach can be very useful for farmers as a decision support tool, helping with decisions such as: what crop/variety to use, when to plant and harvest, when and how much to irrigate, what yield to expect under a specific irrigation system or strategy, when using a certain water quality, and also to allow increasing water use efficiency and crops productivity. The SALTMED model has been calibrated and validated for several field crops, in several parts of the world, including field tomato. However, the greenhouse environment has specific conditions that are not always easy to simulate with generic crop growth models. The objective of this work was to evaluate SALTMED model for a tomato crop grown in unheated greenhouse conditions. Climatic data and crop parameters were recorded during two years, in two greenhouses with different ventilation management, and three different sets of data were used to calibrate and to validate the model. The results showed that the model can accurately simulate soil grown tomato crop yield under Mediterranean unheated greenhouse conditions

Measuring university-to-work success: development of a new scale

Purpose – The purpose of this paper is to develop a subjective multidimensional measure of early career success during university-to-work transition. Design/methodology/approach – The construct of university-to-work success (UWS) was defined in terms of intrinsic and extrinsic career outcomes, and a three-stage study was conducted to create a new scale. Findings – A preliminary set of items was developed and tested by judges. Results showed the items had good content validity. Factor analyses indicated a four-factor structure and a second-order model with subscales to assess: career insertion and satisfaction, confidence in career future, income and financial independence, and adaptation to work. Third, the authors sought to confirm the hypothesized model examining the comparative fit of the scale and two alternative models. Results showed that fits for both the first- and second-order models were acceptable. Research limitations/implications – The proposed model has sound psychometric qualities, although the validated version of the scale was not able to incorporate all constructs envisaged by the initial theoretical model. Results indicated some direction for further refinement. Practical implications – The scale could be used as a tool for self-assessment or as an outcome measure to assess the efficacy of university-to-work programs in applied settings. Originality/value – This study provides a useful single measure to assess early career success during the university-to-work transition, and might facilitate testing of causal models which could help identify factors relevant for successful transition.CAPES, Brasi

Calibration and validation of SALTMED model under dry and wet year conditions using chickpea field data from Southern Portugal

The SALTMED model is one of the few available generic models that can be used to simulate crop growth with an integrated approach that accounts for water, crop, soil, and field management. It is a physically based model using the well-known water and solute transport, evapotranspiration, and water uptake equations. In this paper, the model simulated chickpea growth under different irrigation regimes and a Mediterranean climate. Five different chickpea varieties were studied under irrigation regimes ranging from rainfed to 100 % crop water requirements, in a dry and a wet year. The calibration of the model using one of the chickpea varieties was sufficient for simulating the other varieties, not requiring a specific calibration for each individual chickpea variety. The results of calibration and validation of the SALTMED model showed that the model can simulate very accurately soil moisture content, grain yield, and total dry biomass of different chickpea varieties, in both wet and dry years. This new version of the SALTMED model (v. 3.02.09) has more features and possibilities than the previous versions, providing academics and professionals with a very good tool to manage water, soil, and crops

Variabilidad espacial y temporal del vigor vegetativo en viñedo sin restricciones hídricas en la demanda evapotranspirativa

Aunque generalmente se asume que la respuesta de un cultivo a la dosis de riego seleccionada es homogénea en la totalidad del área cultivada, en la mayoría de los casos esto no se corresponde con la realidad. En este trabajo se presenta un estudio de la variabilidad espacial y temporal del vigor vegetativo en el cultivo del viñedo, mediante el uso de índices de vegetación (NDVI) y la elaboración de los correspondientes mapas estadísticos. El ensayo ha sido realizado en un viñedo experimental de cultivar Tempranillo (Vitis vinífera L.), donde se compararon cuatro bloques aleatorios con un tratamiento de riego al 100% de la demanda evapotranspirativa (ETc) del cultivo. Durante la fase de maduración, se realizaron semanalmente mapas de índices de vegetación mediante el uso de sensores multiespectrales cercanos, montados sobre vehículos terrestres. Se observó que la respuesta en el desarrollo vegetativo no mantuvo una homogeneidad espacio – temporal en las cuatro zonas de estudio, a pesar de haber recibido las mismas prácticas culturales. La utilización de este tipo de herramientas, sensores de vegetación y estadística inferencial, permite detectar zonas diferenciadas en el desarrollo vegetativo, pudiendo ser utilizado para la toma de decisiones sobre el manejo del cultivo, tales como el escalonamiento de la cosecha o la aplicación tanto de abonos como de fitosanitarios, en función del factor que produce dicho descenso de vegetación

Micro-Terroir

El concepto de terroir en el vino está basado en la observación de que diferentes regiones, viñedos o secciones dentro del mismo viñedo, pueden producir vinos con identidades propias y muy diferentes entre sí. Este concepto se cristalizó con el fin de describir los aspectos únicos de un lugar particular (suelo, topografía y clima) que influyen y forman el vino que nace a partir de él. Para una misma posición geográfica, podemos pensar que factores tales como el suelo y la topografía son fijos, en el espacio y en el tiempo, sin embargo las plantas del cultivo de viñedo presentan microvariaciones locales con diversas respuestas adaptativas. En efecto, dentro de un mismo viñedo, aéreas aparentemente uniformes desde un punto de vista pedológico y topográfico presentan plantas con vigores vegetativos totalmente distintos, considerando todos los factores fijos. Estos micro – terroirs vegetativos proporcionan una diferenciación en la maduración de la uva, creando así una variación espacial y temporal en la calidad de la misma. Considerando los demás factores fijos y, partiendo del principio de que la variación espacial y temporal en el vigor vegetativo de una planta es un indicativo de su capacidad productiva, así como del potencial cualitativo del fruto, fueron controladas 80 hectáreas de viñedo mediante un sensor de vegetación. La base de datos, espacial y temporal, obtenida y posteriormente analizada por componentes principales, permitió elaborar zonas homogéneas de tratamiento que denominamos micro – terroirs. Como resultado, se encontró que existe una variabilidad espacial y temporal en las regiones aparentemente uniformes en términos pedológicos y topográficos, lo que sugiere una capacidad de adaptación genética que no siempre es fácil de tener en cuenta. La capacidad de monitorizar la variación espacial y temporal del vigor vegetativo de la vid, permitirá gestionar diferenciadamente las unidades geográficas distintas, desde el punto de vista de la calidad del vino

Increasing farmers’ skills towards a sustainable agriculture

De modo a praticar uma agricultura sustentável, os agricultores devem adotar práticas corretas e respeitadoras do ambiente, utilizando a tecnologia adequada e cumprindo a regulamentação da UE para uma agricultura sustentável. Os desenvolvimentos recentes da ciência e da tecnologia, que poderiam ser um valor acrescentado para a gestão das culturas e da terra, continuam a não ser utilizados em muitas situações por não terem chegado ao conhecimento dos agricultores ou estes não terem sido treinados para os utilizar. O objectivo deste estudo foi o de definir competências no domínio da tecnologia agrícola, em áreas onde ocorreram avanços tecnológicos que podem ajudar os agricultores a praticar uma agricultura mais sustentável. Foram identificadas seis áreas principais: 1) Agricultura de precisão; 2) Proteção integrada; 3) Reutilização agrícola de resíduos orgânicos; 4) Rega gota-a-gota e tecnologias de conservação da água; 5) Energias renováveis e 6) Bioenergia e culturas energéticas. Para cada uma destas áreas foram definidas competências específicas com enfâse na sensibilização sobre os aspectos da sustentabilidade na agricultura e na introdução aos principais desenvolvimentos tecnológicos. Estas competências foram depois utilizadas no desenvolvimento de um novo programa de formação profissional para agricultores, cujos cursos de formação decorreram durante o ano de 2019 na Grécia, Itália e Portugal, para um total de cerca de 600 agricultores

POTENCIAL DE VÁRIAS TECNOLOGIAS PARA MELHORAR A EFICIÊNCIA ENERGÉTICA NA AGRICULTURA

Este trabalho versa sobre o potencial de várias tecnologias para melhorar a eficiência energética na agricultura e consiste num resumo da apresentação feita em Quito, Equador no Primeiro Fórum Ibero-Americano de Ciências para as Energias, em Junho de 2012. Os dados estatísticos nos vários países, relativos ao consumo de energia pelo sector agro-pecuário não reflectem na maior parte dos casos a realidade, pecando por defeito por não se considerarem todos os consumos. O objectivo desta comunicação é mostrar resultados de trabalhos que temos vindo a desenvolver para melhorar tecnologias que permitam potenciar a eficiência energética e redução nos custos de produção neste sector. É de salientar que todas as tecnologias que permitam reduzir o consumo de energia contribuem para a redução de emissões de GEE, e contribuem assim para a melhoria do meio ambiente em geral

Training and Learning Needs for MSc Programs in Sustainable Agriculture

Sustainable agriculture is urgently needed to promote conservation and sustainable resources use in an equitable manner through integrated management of land, water, energy and biodiversity. In this way, education in agriculture emerges as a crucial tool for preparing agricultural technicians, researchers and farmers for productive contributions. Higher education institutions arise with an important mission of education in the context of social transformation and to integrate sustainable development into the educational system as a scientific subject. The aim of this study was to identify the training and learning needs to be included in a MSc program in sustainable agriculture. It was based on a questionnaire prepared and distributed to academics’ experts in Agrarian Sciences in Greece, Italy and Portugal. Technologies, legislation, management and business, local community leadership and marketing were the training needs considered very important expertise’s in sustainable agriculture. Traditional face-to-face learning, experienced farmers as mentors and knowledge sharing mechanisms were rated as very applicable and important. Due to COVID-19 pandemic, online learning methods, which were not considered suitable for a MSc program in sustainable agriculture, became important by providing online education. Information and communication technology and technological tools showed to be important skills for sustainable agricultural practices to effectively implement online learning and to improve the efficient access, exposure and use of up-to-date information of the agricultural sector and awareness of sustainable agricultural practices