ISA - Artigos em Revistas Internacionais
Permanent URI for this collection
The collection includes scientific publications, subject to peer review, published in international journals, including full articles, review articles, data papers and scientific notes.
Browse
Recent Submissions
- Methodology for Obtaining ETo Data for Climate Change Studies: Quality Analysis and Calibration of the Hargreaves–Samani EquationPublication . Ferreira, Antónia; Cameira, Maria do Rosário; Rolim, JoãoReference evapotranspiration (ETo) is an important part of the water cycle, essential for cli- mate studies, water resource management, and agricultural planning. However, accurate estimation of ETo is challenging when meteorological data are insufficient or of low quality. Furthermore, in climate change studies where large amounts of data need to be managed, it is important to minimize the complexity of the ETo calculation. This study presents a comprehensive approach that integrates data quality analysis with two calibration methods—annual and cluster-based—to improve ETo estimates based solely on temperature data from a set of weather stations (WS). First, the quality and integrity of meteorological data from several WS were analyzed to reduce uncertainty. Second, the Hargreaves–Samani equation (HS) is site calibrated using two approaches: (a) annual calibration, where the radiation coefficient (kRs) is adjusted using a data set covering the entire year; (b) cluster- based calibration, where independent radiation coefficients are adjusted for clusters of years and months. The methodology was evaluated for the Alentejo region in Southern Portugal, using data from 1996 to 2023. When using the original HS equation with a kRs = 0.17 ◦C−0.5, ETo was estimated with errors from 14.9% to 22.9% with bias ranging from −9.0% to 8.8%. The annual calibration resulted in kRs values between 0.157 and 0.165 ◦C−0.5 with estimation errors between 13.3% and 20.6% and bias ranging from −1.5% to 1.0% across the different weather stations. Calibration based on clusters of months and years produced unclear results. Dry season months showed better results using cluster-based calibration, while wet season months performed poorly regardless of the calibra- tion approach. The results highlight the importance of meteorological data quality and site-specific calibration for refining temperature-based ETo estimation methods, and for the region studied, the gains do not justify the increased complexity of the cluster-based approach.
- A pilot-scale evaluation of residual sludge quality in a worm-sludge treatment reed bed in the Mediterranean regionPublication . Gholipour, Amir; Fragoso, Rita; Galvão, Ana; Duarte, ElizabethA pilot-scale study on sludge treatment reed beds investigated the combined effects of earthworms and Arundo donax on sewage sludge dewatering and residual sludge quality. Four units were tested: one planted with earthworms, one planted without earthworms, one unplanted with earthworms, and one control, each unit replicated. Over a year, 24 cycles of sludge (dry and volatile solid contents of 24.71 g.L 1, and 19.14 g.L 1) were fed onto the units at a sludge loading rate: 43.59 kg.DS.m 2.year 1. Afterward, the units experienced 132 days of resting period, increasing dry solids from 21 to 70 % and decreasing volatile solids from 81 to 69 % on average (40 % sludge volume reduction). The bottom layers of the planted unit with earthworms showed a 30 % reduction in volatile solids, indicating improved sludge stabilization. Macronutrient abundance in the residual sludge followed the sequence N > Ca > P > K > S > Mg. The planted unit with earthworms reduced micro- nutrient concentrations by 22 % compared to the control unit (Fe > Na > Mn > B > Mo). Earthworms also played a key role in reducing heavy metal concentrations by 11 % compared to the planted unit without earthworms (Zn > Cr > Pb > Ni > Cd). Heavy metal levels in the residual sludge met EU and Portugal standards, with a 99.9 % reduction in Escherichia coli and fecal coliforms. Cost estimation showed centrifugation and W-STRB scenarios cost 167 and 183 €.PE 1 for a ten-year operation, with O&M costs of 7 and 3 €.PE 1.year 1, respectively
- A Farming System Approach to Exploring Drivers of Food Insecurity Among Farm Households in Developing Countries: The Case Study of MozambiquePublication . Abbas, Máriam; Ribeiro, Paulo Flores; Santos, José LimaFarm households, especially in developing countries, are among the most vulnerable to food insecurity and poverty. A farming system approach is largely recognized to play an important role in supporting strategies to improve food security and alleviate poverty among farm households. This paper aims at exploring the drivers of food insecurity among farm households in developing countries, using a farming system approach. It also aims to explore farm households’ perceptions regarding the causes of food shortages and the adopted coping strategies, and how these vary across farming systems. This analysis was based on data extracted from an agricultural census, which were analyzed through scatter plots and plot means with 95% confidence intervals. The results indicate that the factors analyzed (level of specialization, market integration, use of yield-raising and labor-saving inputs, farm size, population density, and rainfall) are important drivers explaining food insecurity among farm households, highlighting important differences across farming systems. The analysis also showed that farm households’ perceptions regarding the causes of food shortages are related with the abovementioned drivers of food insecurity. Our findings suggest that less specialized farming systems with better access to markets, using yield-raising and/or labor-saving inputs, are more likely to be food secure. The farming system approach proved to be a useful approach to explore food insecurity drivers and coping strategies as well as to support policymaking. Moreover, the use of an agricultural census data provides an easily attainable tool to access and analyze farm-level data for policy analysis and to explore and understand a range of issues affecting farm households in developing countries.
- Environmental Risk Assessment of Glyphosate and Aminomethylphosphonic Acid (AMPA) in Portuguese Groundwater EcosystemsPublication . Santos, Inês; Lopes, Ana; Silva, EmíliaThe aim of the present study was to assess the risk related to the exposure of groundwater ecosystems to herbicide glyphosate and its non-relevant metabolite aminomethylphosphonic acid (AMPA) based on the quotient between measured concentrations gathered from the Water Resources Information System of Portugal, and groundwater quality standards set in legislation and estimated from environmental quality standards in surface waters. Glyphosate was analyzed in 103 ground- water samples collected from 80 wells located in 21 aquifer systems from the four hydrogeological units of mainland Portugal, between 2019 and 2021. It was detected in 14% of the total samples; however, only 10% presented concentration levels above 0.1 μg/L, the groundwater quality stan- dard, and none of these values exceeded the value of 8.67 μg/L estimated from the annual average environmental quality standard proposed for glyphosate in surface waters. In comparison, AMPA was detected in only 5% of 63 groundwater samples, in four dug wells. In both compounds, the maximum concentration level was quantified in a dug well located in the O25-Torres Vedras aquifer system, from the Western unit, with 4.69 and 4.24 μg/L for glyphosate and AMPA, respectively. The results of this study demonstrate that it is extremely important to raise awareness and offer training to farmers on the sustainable use of plant protection products and good agricultural practices, in order to prevent groundwater contamination and improve its quality. There is also an urgent need to carry out ecotoxicological tests with further groundwater species from different functional groups in order to obtain a quality standard that accurately represents the groundwater communities.
- Addressing Carbon Storage in Forested Landscape Management Planning—An Optimization Approach and Application in Northwest PortugalPublication . Marques, Susete; Rodrigues, Ana Raquel; Paulo, Joana Amaral; Botequim, Brigite; Borges, Jose G.Climate change is driving worldwide efforts to mitigate and reverse the increasing anthro- pogenic emissions of greenhouse gases. Forests can uptake considerable amounts of carbon from the atmosphere, but management decisions and resultant silvicultural practices can largely influence these ecosystems’ carbon balance. This research presents an approach to help land managers cope with the need to ensure the provision of forest products and services while contributing to mitigating climate change via carbon sequestration. The emphasis is on combining a landscape-level resource capability model with a mathematical programming (LP) optimization method to model and solve a land management problem involving timber production, carbon sequestration, and resistance to wildfire targets. The results of an application on a forested landscape in Northwest Portugal showed that this approach may contribute to analyzing and discussing synergies and trade-offs between these targets. They revealed important trade-offs between carbon sequestration and both timber production and fire resistance
- Chemical and nutritional characterization of loengo (Anisophyllea boehmii) fruits as a source of important bioactive with impact on healthPublication . Lofa, Alcides Morais; Mourato, Miguel; Prista, Catarina; Sousa, Isabel; Ferreira, Ricardo BoavidaIntroduction: Fruits are vital for human health, providing nutrients and other compounds linked to protection against different diseases. Loengo (Anisophyllea boehmii Engl.) produces an edible stone fruit, plum-shaped (drupe), dark blue and maroon or carmine in the ripening stage, which is generally, consumed fresh in the production areas. Characterization of this fruit will contribute to estimate its nutritional and pharmaceutical potential impact. The present work aimed at the physic-chemical, nutritional and antioxidant activity characterization of loengo fruit. Methods: Soluble solid contents (SSC) in the pulp were assessed in juice, at room temperature. Total protein was determined using the Dumas method. In what concerns the mineral composition were determined by ICP-OES. Organic acids identification and quantification was accomplished using a high-performance liquid chromatography (HPLC) system. The total polyphenol contents (TPC) were determined in 96-well microplate assays. Antioxidant activity were determined by 2,2-diphenyl-1-picrylhydrazyl (DPPH) and the ferric reducing antioxidant power (FRAP) assay Results and discussion: Composition, in terms of fresh matter is as follows: pulp soluble sugar content (refractometer) is 19.5% ± 0.02%, and pulp titratable acidity 1.2% ± 0.1% expressed in citric acid; total protein content is 7.4% ± 0.02%, 8.0% ± 0.1%, 16.9% ± 0.2%, for the peel, pulp and seed, respectively. In what concerns the mineral composition, the results obtained show that it is a good source of minerals, mainly potassium and phosphorus, but also calcium, sulfur, and magnesium, with the pulp richer in potassium, the seed in phosphorus, and the peel in calcium. As expected, the pulp showed the highest total soluble sugar content, whereas the seed had the lowest. The main sugars found in the pulp were glucose and fructose. In the peel citric acid was the main organic acid found, together with malic, oxalic, and ascorbic acids. Most antioxidant activity was found in the seed. The results of this work provide important information to recommend the consumption of this fruit for its sweet taste, chemical and nutritional composition, and, most of all, for its richness in total phenolic compounds for it potential to formulate nutraceutical foods.
- Microencapsulation of Essential Oils and Oleoresins: Applications in Food ProductsPublication . Fernandes, Beatriz; Oliveira, M. Conceição; Marques, Ana C.; Santos, Rui Galhano dos; Serrano, CarmoEssential oils (EOs) and oleoresins (ORs) are plant-derived extracts that contain both volatile and non-volatile compounds used for flavoring, coloring, and preservation. In the food industry, they are increasingly used to replace synthetic additives, aligning with consumer demand for natural ingredients, by substituting artificial flavors, colorants, and preservatives. Microcapsules can be added to a vast range of foods and beverages, including bakery products, candies, meat products, and sauces, as well as active food packages. However, incorporating EOs and ORs into foods and beverages can be difficult due to their hydrophobic nature and poor stability when exposed to light, oxygen, moisture, and temperature. Microencapsulation techniques address these challenges by enhancing their stability during storage, protecting sensitive molecules from reacting in the food matrix, providing controlled release of the core ingredient, and improving dispersion in the medium. There is a lack of articles that research, develop, and optimize formulations of microencapsulated EOs and ORs to be incorporated into food products. Microencapsulated ORs are overlooked by the food industry, whilst presenting great potential as natural and more stable alternatives to synthetic flavors, colorants, and preservatives than the pure extract. This review explores the more common microencapsulation methods of EOs and ORs employed in the food industry, with spray drying being the most widely used at an industrial scale. New emerging techniques are explored, with a special focus on spray drying-based technologies. Categories of wall materials and encapsulated ingredients are presented, and their applications in the food and beverage industry are listed.
- Productive, Physiological, and Environmental Implications of Reducing Crude Protein Content in Swine Diets: A ReviewPublication . Almeida, André; Latorre, Maria Angeles; Alvarez-Rodriguez, JavierPig production is one of the most important providers of high-quality proteins and amino acids (AAs) to human nutrition. In this sector, feeding has an important economic and environmental impact. A strategy to reduce production costs and negative sustainability effects is reducing dietary crude protein (CP) contents with or without AA supplementation. This review addresses the different aspects related to this strategy, particularly the effects on growth performance and pork traits in piglets and growing and finishing pigs, as well as the physiological molecular mechanisms’ underlying effects. Insight is also provided into the effects of dietary CP reduction on the productive performances of alternative pig production systems and breeding boars and sows. Finally, an overview is conducted on the effects of dietary CP reduction on ammonia, odor, and greenhouse gas emissions arising from pig production systems. Overall, CP reduction may lead to production losses, albeit they can be, to some extent, hindered by adequate AA supplementation. Losses are particularly relevant during the post-weaning phase, whereas in finishing pigs, it may bring additional benefits, such as high intramuscular fat contents in some markets or improved gut barrier function with benefits to the animals’ health and welfare, as well as decreased ammonia emissions to the environment.
- Single and basal crop coefficients for temperate climate fruit trees, vines and shrubs with consideration of fraction of ground cover, height, and training systemPublication . López‑Urrea, Ramón; Oliveira, Cristina M.; Montoya, Francisco; Paredes, Paula; Pereira, Luis S.The objective of the present review article was to update the standard single (K c ) and basal (K cb ) crop coefficients published in the FAO Irrigation and Drainage Paper No. 56 (FAO56), focusing on temperate climate fruit trees (pome, stone and nut fruit trees), vines and shrubs (kiwi, hop and blue- and blackberries). Standard conditions refer to crops grown in medium to large fields, having enough fetch for non-impeding accurate use of flux measuring equipment to represent non-limiting conditions of crop evapotranspiration, ETc . Moreover, the crop needs to be managed without soil water deficit, free of pests and diseases, and must be able to reach full production under the given environmental conditions. For this purpose, more than 150 articles published over the last 25 years were reviewed. Of these, we selected 76 that refer to case studies that reporting on appropriate yield conditions, describe adequate ETc measurement and adopt the FAO reference evapotranspiration or another method closely related to it. The selection of papers to be analysed followed the same methods as the companion papers on Mediterranean woody fruit crops (Pereira et al. 2023), and on tropical and subtropical ones (Paredes et al. 2024). The literature review focused on articles that are in line with the FAO56 methodology; that is, where the grass reference evapotranspiration (ETo ) was computed with the FAO Penman–Monteith ETo , the ASCE Penman–Monteith ETo equations, or other equations whose results relate well to the former. In addition, where the crop evapotranspiration (ETc ) and/or crop transpiration (Tc ) were determined with sufficient accuracy from field observations in crops grown under standard, well- watered conditions, i.e., under pristine (i.e., non-stress cropping conditions) or eustress (i.e., “good stress”) conditions. Information collected from the selected studies included cultivar and rootstock, plant density and spacing, training system, fraction of ground cover or intercepted PAR radiation, crop height and age. Additional data were gathered on irrigation system and strategy for full or deficit irrigation. The K c and K cb values reported were recomputed and grouped according to the degree of ground cover, training system and plant density. Thus, the proposed tabulated standard K c and K cb values for initial, mid- and end-season are based on the values obtained from field observations reported in the selected papers, and on the ranges of Kc /K cb values previously tabulated, mainly in FAO56. The currently tabulated values are updated, with the aim being their use in orchard management. They should consist of the upper limit of K c /K cb application, and take into account the general awareness of water scarcity and water conservation, thus helping improve the accuracy in estimating crop water requirements and optimizing irrigation scheduling.
- Single and basal crop coefficients for estimation of water use of tree and vine woody crops with consideration of fraction of ground cover, height, and training system for Mediterranean and warm temperate fruit and leaf cropsPublication . Pereira, Luis S.; Paredes, Paula; Oliveira, Cristina M.; Montoya, Francisco; López‑Urrea, Ramón; Salman, MaherThis paper reviews the research on the FAO56 single and basal crop coefficients of fruit trees and vines performed over the past twenty-five years and focus on Mediterranean and warm temperate trees and vines. Two companion papers (López-Urrea et al., (2023) Single and basal crop coefficients for estimation of water use of tree and vine woody crops with consideration of fraction of ground cover, height, and training system for temperate climate fruit crops. Irrig Sci (submitted); Paredes et al. (2023) Single and basal crop coefficients for estimation of water use of tree and vine woody crops with consideration of fraction of ground cover, height, and training system for tropical and subtropical fruit crops. Irrig Sci (submitted)) are dedicated, respectively, to Temperate and to Tropical and Subtropical trees and vines. The main objective of the paper is to update available information on single (Kc ) and basal (Kcb ) standard crop coefficients, and to provide for updating and completing the FAO56 tabulated Kc and Kcb. The Kc is the ratio between non-stressed crop evapotranspiration (ETc ) and the grass reference evapotranspiration (ETo ), while Kcb is the ratio between crop transpiration (Tc ) and ETo . The selection and analysis of the literature were performed considering only studies that adhere to the FAO56 method, thus computing ETo with the FAO Penman–Monteith ETo equation, the ASCE grass ETo , or another equation that could be properly related with the former, and ETc , or Tc , was obtained using properly accurate field measurements on crops under pristine or eustress conditions. The crops considered refer to Mediterranean (grapes and olive) and warm temperate areas (avocado, citrus, per- simmon, loquat, and tea) fruit and leaf crops. Papers satisfying the above conditions were selected to provide for standard Kc and Kcb data. Preferably, studies should report on the crop cultivar and rootstock, planting density or plant spacing, fraction of ground cover (f c ), crop height (h), crop age and training systems. Additional information was collected on pruning and irrigation method and strategy. The ranges of reported Kc and Kcb values were grouped according to crop density in relation with f c, h, and the training system, namely vase, hedgerow, or trellis systems. Literature collected Kc or Kcb values were compared with previously tabulated Kc and Kcb values, namely in FAO56, to define the standard Kc and Kcb values for the referred selected crops. The tabulated values are, therefore, transferable to other locations and aimed for use in crop water requirement computations and modeling, mainly for irrigation planning and scheduling, and for supporting improved water use and saving in orchards and vineyards.