Percorrer por autor "Martins, Sandra"
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- An innovation project at the IPB: higher education for allPublication . Semedo, José; Martins, Cláudia; Rocha, João; Santos, Jorge; Martins, SandraEpistemologically speaking, higher education (HE) is oftentimes regarded as a place of “receiving” knowledge and skills rather than “giving”, a place of watching creation happen rather than participating in this creation process. However, in the new millennium, HE institutions have gradually been rediscovering constructivism and broadening its scope to a more participatory approach. Thus, cocreation ecosystems, quoting the IPB’s president’s terminology, have mushroomed and given rise to a number of projects, experiences and work philosophies and methodologies, among which Demola at the IPB is worth to mention. Participatory methodologies were set in train by a team of professors-reseachers, junior researchers and collaborators with impairments for the project “Culture for All Bragança” that the IPB carried out for the Municipality of Bragança. Throughout 2 years, we worked side by side in producing a number of resources which enabled us to amass experience and expertise in cocreation, specifically in local cultural venues. This inspired us to focus on the IPB as a whole, though at a first stage only at the campus, in order to set up similar resources that could cater for different needs of different groups of people, be it students or staff of the IPB. Ultimately, our goal is to help make the IPB a more accessible institution for diverse people. As such, we wish to report on the development of this project from the joint diagnosis of the accessibility conditions of the 3 schools at the campus, along with the central services, to the production of 2.5D/high relief plans and their mediation texts, which include audiodescription, Portuguese Sign Language and easy language. By working together with people with impairments, we sought to grapple with challenges that are posed by contemporary societal demands but also with the future employment landscape, which requires professionals to be able to deal with diversity be it in terms of functionality or ethnical, to name just a few.
- Annual legume cover crops enhance the sustainability of rainfed olive orchards: from leaf ionome to tree physiologyPublication . Correia, Carlos M.; Martins, Sandra; Silva, Ermelinda; Brito, Cátia; Pinto, Luís; Moutinho-Pereira, José; Rodrigues, M.A.; Gonçalves, AlexandreThe olive sector has an important economic, social, cultural and ecological relevance in the Mediterranean region, where tillage and herbicides application still are generalized practices, although the recommendations of UE policy for a more sustainable agriculture. Cover crops with self-reseeding legumes of short-cycle, with mulch of dead vegetation during the dry season, is our option for soil management in olive tree rainfed orchards, as they provide protection against erosion, improve the physical and chemical properties, nitrogen fixation and soil moisture, enhance biodiversity and landscape beautification, while contribute to mitigation and adaptation to climate change and enable the organic production mode. The experiment was carried out during 2016 and 2017 on a commercial orchard (cv. Cobrançosa) in Northeast Portugal. The treatments laid out were: (1) ordinary tillage techniques used by local growers (two tillage trips per year) and (2) a mixture of 11 self-reseeding annual legumes (AL). The results revealed that cover crops influence positively the tree water status during the drought season, as well the nutritional status, namely the foliar concentrations of nitrogen, magnesium and manganese, both during the winter resting period and in summer, at endocarp sclerification. As a result, AL trees presented greater physiological performance during the summer, as evidenced by higher net photosynthetic rate, mainly due to inferior stomatal limitations, lower investment of resources in defensive metabolites, and enhanced yield. These results indicate that cover cropping should be included in the portfolio of adaptive management strategies against climate change, contributing to the sustainability of rainfed orchards.
- Aplicação de fungos micorrízicos arbusculares reduziu o crescimento de plantas jovens de oliveira devido a competição por fotoassimiladosPublication . Lopes, João; Correia, Carlos M.; Gonçalves, Alexandre; Silva, Ermelinda; Martins, Sandra; Arrobas, Margarida; Rodrigues, M.A.Neste trabalho avaliou-se o efeito de fungos micorrízicos comerciais no desenvolvimento de oliveiras jovens cultivadas em estufa na fase de viveiro. O estudo constou de duas experiências, uma organizada num fatorial com três cultivares (Cobrançosa, Madural e Verdeal Transmontana) e três tratamentos de solo (fungos micorrízicos comerciais, zeólitos e testemunha) e outra segundo um delineamento completamente casualizado com quatro tratamentos [fungos micorrízicos comerciais, solo esterilizado, solo esterilizado mais um extrato de solo sem fungos micorrízicos arbusculares e testemunha]. A Cobrançosa desenvolveu-se melhor que as outras cultivares, apresentando bom enraizamento e melhores características iniciais de crescimento. As plantas micorrizadas apresentaram crescimento reduzido em comparação com as da testemunha. O resultado foi explicado pela competição por fotoassimilados entre o crescimento das plantas e o estabelecimento da simbiose, com a expansão das hifas dos fungos. O facto de as plantas apresentarem reduzida área foliar no início da experiência e a estufa ter uma cobertura de policarbonato de parede dupla, um tanto opaca à radiação fotossintética ativa, podem ter contribuído para reduzir a atividade fotossintética e retardar o crescimento das plantas inoculadas. Porém, nos vasos micorrizados, o carbono orgânico do solo e os teores da maioria dos nutrientes aumentaram, provavelmente devido à presença de hifas de fungos nas amostras e ao aumento da atividade enzimática do solo. Os zeólitos reduziram a produção de matéria seca das plantas e a concentração de fósforo nos tecidos em relação à testemunha, aumentando a disponibilidade no solo dos catiões que entram em sua composição. A esterilização do solo parece ter reduzido a biodisponibilidade de fósforo, talvez por ter inativado enzimas do solo. O extrato de solo sem fungos micorrízicos arbusculares não apresentou benefícios para as plantas ou qualquer efeito relevante nas propriedades do solo.
- Application of anti-hail net in apple orchards: effects on fruits chemical characteristicsPublication . Martins-Gomes, Carlos; Pinto, Luís; Silva, Ermelinda; Martins, Sandra; Gonçalves, Alexandre; Brito, Cátia; Moutinho-Pereira, José; Rodrigues, M.A.; Correia, Carlos M.; Nunes, Fernando M.Apple production in Portugal, over the last 15 years, has been subjected to increasing crop damage due to hailstorms and related meteorological extreme conditions. This problem has led farmers and researchers to find practical solutions to protect the orchards, such is the case of netting devices. The application of anti-hail nets in apple tree orchards looks to provide protection against the roughest meteorological events (such as hail, strong winds, and sunburn), while avoiding to upset the development of the plant and or, if possible, helping to improve the plant’s productivity. During 2016, this work was carried out in Carrazeda de Ansiães, a northeast Portuguese plateau zone that is a primary location for apple production, and the application of a grey anti-hail net, which reduces photosynthetically active radiation by 12 %, was tested in an orchard with the cultivars Golden delicious and Fuji of apple tree (Malus domestica Borkh). Control without screen net applied was also used. In order to understand the effects of the net, apples were collected and analysed for their chemical characteristics (total phenols, ortho-diphenols and flavonoids content, ABTS and polyphenolic profile). The obtained results in apple peel revealed, in both cultivars, a decrease in total phenols, ortho-diphenols and flavonoids concentration, whereas in the Fuji cultivar the antioxidant activity, determined by the ABTS assay, was maintained. Pulp results showed little difference with lower (P<0.001) ortho-diphenols content in Fuji cultivar and slightly lower (P<0.05) ABTS activity in Golden delicious cultivar. Peel and pulp methanolic extracts were analysed by HPLC-DAD. The phenolic profile was similar for both cultivars, with the exception of anthocyanins, being identified chlorogenic acid and derivatives of quercetin. The antihail net did not affect the phenolic profile, only decreased the polyphenols concentration. The use of a grey anti-hail net on apple orchards is a suitable alternative for the protection of apple trees against hail ensuring the production of the crop without compromising fruit quality.
- Arbuscular mycorrhizal fungi inoculation reduced the growth of pre-rooted olive cuttings in a greenhousePublication . Lopes, João Ilídio; Correia, Carlos M.; Gonçalves, Alexandre; Silva, Ermelinda; Martins, Sandra; Arrobas, Margarida; Rodrigues, M.A.The effect of commercial mycorrhizal fungi on pre-rooted olive cuttings was assessed. The study consisted of two experiments, the first arranged as a factorial design with three cultivars (Cobrançosa, Madural, and Verdeal Transmontana) and three soil treatments (commercial mycorrhizal fungi, zeolites, and control) and the second as a completely randomized design with three treatments (commercial mycorrhizal fungi, sterilized soil, and control). Cobrançosa grew better than the other cultivars, showing good rooting and initial growth features. Mycorrhizal plants showed reduced growth in comparison to those of the untreated control. This result was explained by competition for photosynthates between plant growth and the expansion of fungi hyphae. Cuttings of reduced leaf area and a twin-wall polycarbonate cover of the greenhouse, somewhat opaque to photosynthetic active radiation, may also have contributed to limit the maximum photosynthetic rate and delay the growth of the inoculated plants. Accordingly, in the mycorrhizal pots, the soil organic carbon (C) increased, probably due to the presence of fungi hyphae in soil samples. Zeolites reduced plant dry matter (DM) yield and tissue phosphorus (P) concentration compared to the control, while increasing the availability in the soil of the cations present in their initial composition. Soil sterilization seems to have reduced soil P bioavailability by inactivating soil enzymes. This study showed that the inoculation with mycorrhizal fungi of pre-rooted cuttings can delay their initial growth. Although these plants may be better prepared to grow in the field, in the short term, their lower development can be a problem for the nurseryman.
- Biomass and nutrient release dynamics of decomposing rolling down legume cover crops in a steep-sloped Mediterranean vineyardPublication . Brito, Cátia; Martins, Sandra; Saraiva, Francisco; Roque, João; Arrobas, Margarida; Rodrigues, Manuel Ângelo; Correia, CarlosWell-managed cover crops are gaining traction as an alternative to conventional tillage, offering a range of agronomic and ecological benefits. This field study, conducted in a commercial vineyard in the Douro region (Portugal) during the 2022/2023 growing season, evaluated the decomposition dynamics and nutrient release from different legume cover crop residues over a period of 183 days after sowing and 114 days after rolling. These mixtures consisted of subterranean clovers (SC), low-growing (LG), and moderately-growing (MG) legumes. MG legumes produced the highest biomass (7.8 t ha-1), followed by LG (7.2 t ha-1) and SC (5.9 kg ha-1). MG residues decomposed more rapidly, potentially meeting early grapevine nutrient demands. SC residues decomposed more slowly, retaining nutrients over longer periods and acting as a sustained source of fertility, while LG legumes provided a balance between rapid and gradual nutrient release. Biomass production peaked before rolling termination, suggesting that the lower canopy foliage might have started decomposing as the crops reached maximum vegetative expansion and early seed formation, reflecting the dry, hot environmental conditions during the study year. The observed nutrient release from cover crop residues, particularly during the first 45 days post-termination, suggested a potential to support grapevine nutrient requirements, although direct uptake by grapevines was not assessed in this study. SC residues retained higher levels of key macronutrients and micronutrients over time. These findings highlight the importance of selecting legume cover crop mixtures aligned with vineyard management goals, whether rapid nutrient supply or sustained soil fertility. The study also underscores the influence of environmental conditions, residue composition and termination timing on nutrient dynamics. Long-term research is recommended to evaluate cover crops' chemical composition, cumulative effects on soil organic carbon (C) and nutrients, microbial activity and effects on grapevine performance across diverse Mediterranean environments.
- Clinoptilolite zeolite foliar application on rainfed olive trees: effects on physiology, biochemistry, growth, yield and olive oil qualityPublication . Martins, Sandra; Gonçalves, Alexandre; Silva, Ermelinda; Brito, Cátia; Pinto, Luís; Arrobas, Margarida; Rodrigues, M.A.; Nunes, Fernando M.; Correia, Carlos M.With the advances of climate change, it is expected harmful consequences to olive tree (Olea europaea L.). Therefore, it is necessary to develop cost-effective practices to reduce the vulnerability of olive crops to the adverse impacts of environmental stresses. Rainfed olive trees were sprayed with zeolites, natural crystalline aluminosilicates, and its effects on photosynthetic activity, phenolic composition, antioxidant activity, leaf minerais concentrations, plant growth, yield, and olive oil quality were assessed. Zeolites application enhanced photosynthetic activity, as well the concentrations of N, Mg, Cu, Zn and Mn in leaves, and changed the secondary metabolism, with decrease oftotal phenols, ortho-diphenols and total antioxidant activity, signs of lower oxidative stress. As consequence, zeolites boosted plant growth, crop yield, and size and weight of fruits. The foliar spray did not significantly affect the oil quality indices free acidity, peroxide value and Km and K270 coefficients. This study strongly suggests that folial' zeolites might be an effective strategy to mitigate the adverse environmental conditions.
- Combined biochar and organic waste have little effect on chemical soil properties and plant growthPublication . Rodrigues, M.A.; Garmus, Taís Gabriele; Arrobas, Margarida; Gonçalves, Alexandre; Silva, Ermelinda; Rocha, Luís; Pinto, Luís; Brito, Cátia; Martins, Sandra; Vargas, Thiago de Oliveira; Correia, Carlos M.Biochar has received great attention as a soil conditioner since it can potentially sequester carbon (C) in soil, enhance soil physical, chemical and biological properties and improve crop productivity. This study reports the results of a pot experiment with olive (Olea europaea L.), carried out in an acidic and clay loam textured soil, and cultivated during two growing seasons under eight fertilization treatments. They included mineral fertilization equivalent to a rate of 100 kg ha-1 of N, P2O5 and K2O (NPK), biochar applied at a rate of 10 (B10), and at 20 (B20) t biochar ha-1, biochar-NPK mixture (B10+NPK), biochar-waste mixtures with mushroom waste compost (B10+MWC), olive mill waste (B10 + OMW), and municipal solid waste (B10+MSW), the organic materials applied at a rate of 20 t ha-1, together with a treatment without fertilization (control). Biochar in the B20 treatment increased the soil C content in comparison to the control. Biochar in the B10+NPK treatment reduced soil nitrate levels compared to NPK treatment. No other benefits to soil properties, nutrient uptake or plant growth were observed with the use of biochar or any positive synergistic effect with the mixture of biochar with the other organic amendments. MSW, OMW and MWC tended to increase soil pH in comparison to the control. Most of the studies with biochar were carried out in soils with edaphic limitations or harsh environmental conditions limiting plant growth, which may have facilitated the detection of favorable effects. Under less limited soils or stressful conditions for plants, such as the ones established in this experiment, the benefits of using biochar were poor.
- Combining zeolites with early-maturing annual legume cover crops in rainfed orchards: effects on yield, fatty acid composition and polyphenolic profile of olives and olive oilPublication . Martins, Sandra; Silva, Ermelinda; Brito, Cátia; Pinto, Luís; Martins-Gomes, Carlos; Gonçalves, Alexandre; Arrobas, Margarida; Rodrigues, M.A.; Correia, Carlos M.; Nunes, Fernando M.Under climate change threats, there is a growing need to adapt the conventional agronomic practices used in rainfed olive orchards by sustainable practices, in order to ensure adequate crop yield and olive oil quality and to preserve soil health. Therefore, for two years, the effects of conventional tillage practice (T) and two sustainable soil management strategies, a leguminous cover crop (LC) and its combination with natural zeolites (ZL), on the yield, fatty acid composition, polyphenolic profile and quality indices of olive fruits and oil were evaluated. Crop yield was significantly increased by LC and ZL in the first year. Although in the second year no significant differences were verified, the cumulative yield increased significantly by 31.6% and 35.5% in LC and ZL trees, respectively. LC enhanced the moisture and size of olives, while ZL increased, in general, the concentrations of oleuropein, verbascoside, caffeic acid and epicatechin, as well the oleic/linoleic ratio in fruits and the levels of 3,4-dihydroxyphenylglycol, tyrosol, verbascoside and caffeic acid in olive oil. Despite the higher concentration of total phenols in the fruits and oil from T trees in the warmer and dryer year, the quality of the oil decreased, mainly when compared with ZL, as evidenced by the peroxide value and K232 and K270 coefficients. In short, both sustainable soil management strategies appear to be promising practices to implement in olive orchards under rainfed conditions, but the innovative strategy of combining zeolites with legume cover crops, first reported in the present study, confers advantages from a nutritional and technological point of view. Nevertheless, studies subjected to the long-term use of these practices should be conducted to ensure the sustainability of the crop yield and olive oil quality.
- Consumo de estimulantes cerebrais por estudantes do Instituto Politécnico de BragançaPublication . Nascimento, Luís; Midões, Cristiana; Pinto, Isabel C.; Teixeira, Helena; Queirós, Patrícia; Martins, SandraOs estimulantes cerebrais são frequentemente utilizados por jovens estudantes que pretendem aumentar o desempenho cognitivo, mas também serem capazes de manter alerta e despertos por mais tempo. O objetivo do presente estudo foi caracterizar os hábitos de consumo de estimulantes cerebrais pelos alunos do Instituto Politécnico de Bragança (IPB), motivos e fatores associados. Realizou-se um estudo descritivo-correlacional, com 303 estudantes matriculados no IPB em 2018/2019, com amostragem não probabilística por conveniência. Para recolha de dados, utilizou-se um questionário online de autopreenchimento, com questões demográficas e comportamentais sobre o uso de estimulantes cerebrais. Para análise dos dados foram utilizadas estatística descritiva e inferencial através do teste de independência do Qui-quadrado, com um nível de significância de 5%. Os resultados revelaram uma média de idades de 23,2 anos (± 5,166) e predominância do sexo feminino (63,0%). A maioria dos participantes (54,1%) referiram que já consumiram algum estimulante cerebral, por autoiniciativa (81,7%), sendo o café (79,3%) e as bebidas energéticas (37,8%) os mais utilizados atualmente e o metilfenidato (1,8%) o menos utilizado. Os motivos de consumo mais referidos foram o aumento da capacidade cognitiva (32,1%) e a diminuição da fadiga e cansaço (20,0%). O consumo de estimulantes está associado ao sexo e ao ano frequentado, sendo mais frequente em estudantes do sexo feminino (69,5%, p=0,011) e a frequentar o 3º ano (29,9%, p=0,028). A utilização de estimulantes cerebrais por estudantes do IPB é uma realidade, sendo a cafeína e as bebidas energéticas as substâncias mais utilizadas, por autoiniciativa. As mulheres apresentam níveis de consumo superior aos homens e esta tendência manifesta-se também em estudantes de 3º ano. Considerando os resultados deste estudo, sugere-se promover o aumento da literacia em saúde e alertar para a utilização desregulada destas substâncias.