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Fertilização de lameiros naturais: produtividade e composição química da vegetação

Os lameiros são pastagens seminaturais de montanha com elevada predominância no centro e Norte de Portugal, de elevado valor ecológico e a base de suporte da atividade pecuária local. A produtividade e a composição florística dos lameiros têm sido estudados em função de gradientes ecológicos diversos, mas poucos estudo têm incluído diferentes estratégias de fertilização com incorporação de micronutrientes. Nest...

The effect of different winter cover crops on sorghum nutritional status and dr...

Growing winter cover crops has a great agroecological meaning, since it allow maintaining the residual inorganic N in the soil/plant system, thus avoiding leaching of N (Rodrigues et al., 2002). As winter cover crops, it can be grown diverse species (Jensen, 1992). If legume species were used, they can access atmospheric N through the establishment of a symbiotic relationship with N-fixing bacteria (Russelle, 2...

Nitrogen mineralized during sorghum growth after soil incorporation of differen...

Growing catch crops during the autumn/winter period is a strategy of high ecological significance since it allows reducing the residual inorganic-N present in the soil after the summer season (Rodrigues et al., 2002). Thus, winter catch crops reduce the risk of denitrification and nitrate leaching associated to the excess of rain of the autumn/winter months. Incidentally, the evergreen systems confer several ot...

Particulate matter and health risk under a changing climate: assessment for Por...

In this work the potential impacts of climate-induced changes in air pollution levels and its impacts on population health was investigated. The IPCC scenario (SRES A2) was used to analyse the effects of climate on future PM10 concentrations over Portugal and their impact on short-term population exposure and mortality. The air quality modelling system has been applied with high spatial resolution looking on cl...

Comparison of the dehydration kinetics of solid state compounds of 2-methoxyben...

Divalent metal complexes of ligand 2-methoxybenzylidenepyruvate with Fe, Co, Ni, Cu and Zn as well as sodium salt were synthesized and investigated in the solid state. TG curves of these compounds were obtained with masses sample of 1 and 5mg under nitrogen atmosphere. Different heating rates were used to characterize and study these compounds from the kinetic point of view. The activation energy and pre-expone...

Parâmetros hematológicos de jumentas gestantes em diferentes períodos

The hematological parameters and total protein concentration in healthy donkeys during pregnancy, under grass handling conditions in tropical weather, were evaluated. Fifth-two Marchador Brasileiro breed healthy donkeys, ranging from 8 to 16 years old, were evaluated, 36 of which were pregnant. The animals were separated in four groups: non pregnant (control), pregnancy from 25 to 110 days (first phase), from 1...

Ovariectomy does not affect the cardiac sympathovagal balance of female SHR but...

The low incidence of cardiovascular diseases, including hypertension, in premenopausal women has led to the conclusion that ovarian hormones may have a protective effect on the cardiovascular system. We evaluated the effects of ovariectomy and/or estradiol on sympathovagal balance and heart rate variability (HRV) in female spontaneously hypertensive rats (SHR) with tachycardia and compared them to Wistar rats (...

Influência da incorporação de resíduo de escória de fluxo de soldagem nas propr...

O processo de soldagem a arco submerso é empregado em grande escala na indústria metal-mecânica. No entanto, este processo gera enorme quantidade de resíduo de escória. Em geral, este resíduo vem sendo disposto em lixões. Nos últimos anos, a área de cerâmica tem atraído grande atenção para reciclagem de resíduos industriais. Neste trabalho foi feito um estudo objetivando avaliar a influência do resíduo de escór...

Geochronology and petrogenesis of late-Variscan plutonism, NW Portugal : synthe...

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