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This study aimed to identify potential sources of organic matter in sediment, using stable isotopes of carbon (delta13C) and nitrogen (delta15N). Sediment samples were gathered from the margin and in center of three subsystems: Ivinheima, Paraná and Baia, in August/2001. The samples were fractionated granulometrically and separated by size (< 200 µm; 70-200 µm; > 70 µm), prepared and sent to CENA / USP, for identifying the isotopes proportions. Significant differences were detected in the isotopic ratios of the sediment only between sampling stations. The Baía channel presented the lowest delta13C values, while the highest ones were recorded in Paraná river. At this last, delta15N values were negative (-14.41‰). We did not verify significant difference in isotopic composition between the particle sizes of sediment, and between the sampling points. The main sources of carbon for the sediment were C3 macrophytes, periphyton and particulate organic carbon (POC).

Neste trabalho avaliou-se o efeito da data de sementeira nas características de produção e composição em açúcares do sorgo sacarino, em função das quais se estimou o potencial de produção de bioetanol a partir desta cultura. O estudo foi conduzido durante dois anos (2005 e 2006), com a variedade de sorgo sacarino Madhura. A sementeira foi efectuada nas datas de 17 de maio, 31 de maio, 14 de junho e 28 de junho. Na sementeira efectuada a 17 de maio a produção de caules verdes e secos atingiu os valores de 66 e 13,8 t ha-1, respectivamente, as quais foram significativamente superiores às obtidas nas sementeiras de junho. A produção máxima de açúcar naquele mês foi de 4,6 t ha-1, o que corresponde à produção estimada de 2300 L ha-1 de bioetanol. Os resultados alcançados permitem concluir que as datas de sementeira de maio foram as que melhor potenciaram a aptidão do sorgo sacarino como cultura energética, para a produção de bioetanol. Revista de Ciências Agrárias, vol. 36 n.º 3 (2013)

Climate change is bound to impact the water cycle and water availability, compounding the sustainable management of its quantity and quality. Groundwater is bound to suffer the impacts of climate change, coupled with those of land use changes, population and its lifestyles evolution. Climate change studies normaly have a 50 to 100 years horizon, which is a challenge for decision makers, who usually rely on relatively short therm data and projections to implement their management policies. BINGO Project tries to address this gap, by providing information of climate change impacts, including those of extreme events, on the water cycle for the short-tomedium term. Climate change impacts on groundwater rely on mathematical modeling, using recharge projections obtained from the climate forecasts of the Regional Climate Models set up for Europe. Sea level change is also a component of this analysis and its ensuing impacts of saltwater intrusion on the coastal and estuarine areas of Aluviões do Tejo and Bacia do Tejo-Sado/Margem Esquerda aquifers. 4p DHA/NRE

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. This research was funded by the Foundation for Science and Technology (FCT, Portugal) and FEDER under Programme PT2020 for financiai support to ClTAB (UIDB/04033/2020), and the Operational Group "Novas práticas em olivais de sequeiro: estratégias de mitigação e adaptação às alterações climáticas" I funded by PT2020 and EAFRD (European Agricultural Fund for Rural Development). Sandra Martins acknowledges the financiai support provided by the FCT-Portuguese Foundation for Science and Technology (PD/BD/135327/2017), under the Doctoral programme "Agricultural Production Chains-from fork to farm". info:eu-repo/semantics/publishedVersion

Objetivou-se analisar os efeitos das externalidades negativas no meio ambiente, abordar o Teorema de Coase no que se refere ao problema de definição dos direitos de propriedade. Adicionalmente, o trabalho explica a teoria econômica da externalidade e ilustra com exemplos. Descreve o comportamento econômico da externalidade na produção agropecuária e mostra de que modo ela cria ineficiência de mercado. Posteriormente, são avaliadas algumas medidas compensatórias para corrigir essas ineficiências. Nesse sentido, argumenta-se em favor da preservação ambiental como requisito básico da manutenção do desenvolvimento agrícola sustentado. Infere-se que modernização da agricultura brasileira teve importância fundamental para o crescimento econômico do País, apesar de que a prioridade dada ao aumento de produtividade pode ter motivado desequilíbrios no meio ambiente.----------------------The objective was to examine the effects of negative externalities in the environment, address the Coase theorem, as regards the problem of definition of property rights. Additionally, the work explains the economic theory of externalities and illustrated with examples. It describes the behavior of economic externalities in production agriculture and shows in what way it creates inefficiency of the market. Subsequently, are evaluated some compensatory measures to correct these inefficiencies. Therefore, it is argued in favor of environmental preservation as a basic requirement of maintaining the sustained agricultural development. It follows that modernization of Brazilian agriculture has fundamental importance for the economic growth of the country, despite the fact that the priority given to increasing productivity may have motivated imbalances in the environment.

This paper analyzes the production diversity among Brazilian agricultural family farms, using the DAP (declaration of Pronaf entitlement). The diversity is measured with a Simpson index, that goes from zero, for monocultures, to one. Production is considerably diversified in these types of farms. 57% of them have a diversification index above 0,35, although it has been noticed an increase in specialization in recent years. The share of monoculture farms rose from 25% in 2012 to 33% in 2014. The diversification index is set as the dependent variable on a Tobit regression with variables that are commonly used to explain the decision to diversify, such as regional dummies, farm size, number of farms, farmer's age, income from social benefits, education, gross production, or a dummy for access to technical assistance. All of these variables have significant effects on production diversity. The results suggest a strong regional bias in terms of diversification, as well as the importance of technical assistance and the availability of technologies in order to spur diversification among family farmers.

The major objective of this chapter is to analyse and briefly describe the evolution of Portuguese agriculture in the context of the European Agriculture. It is not a comprehensive analysis. It is a sketch of its major changes due to major aspects that had influenced in particular the Common Agricultural Policy, and how has evolved with respect to changes in CAP orientation and reforms. This analysis provides an example that might be useful to understand what can be done in the future both in Portugal as in other countries In some aspects figures about these countries including Poland will be presented to benchmark the analysis. Besides this introduction, the chapter has five additional sections. In the next section, background on the Portuguese agriculture and policy before accession is provided. Then, in the third, socio-economic structural characteristics of Portuguese agriculture and their evolution for the last four decades are briefly presented. In the fourth section analysis turns read and understand the evolution as major implications of changes in agricultural policy from CAP reforms. In the fifth section we turn to aspects that are the focus of post-2013 CAP reform and 14 relate them to Portuguese status. Finally, as a conclusion, we look for CAP and the sustainable orientations for Portuguese farmers.

This document aims to provide information about the actions planned with the students within the SAL - Environmental Seed project, as well as to support its preparation. SAL - Seed Environment is a pilot project to raise environmental awareness and promote changes in food consumption among the population. These objectives will be achieved by sharing knowledge about the importance of more sustainable production and consumption practices in the school community. Through information, awareness, training and active participation, from the place of production to the place of consumption, the aim is to encourage more informed choices and, consequently, promote changes in consumption habits and more sustainable behaviour.

Abstract Objectives: During summer in Mediterranean regions, well adapted native cattle breeds present differences in environmental tolerance. The objective of this study was to compare heat tolerance of Alentejana and Mertolenga heifers under direct solar radiation, by quantifying the pathways of evaporative thermolysis and thermostability. Materials and Methods: The experiment was carried out in 5 days. 6 Alentejana and 6 Mertolenga heifers were kept under direct solar radiation, in individual stalls (3.0 —1.1 m) and restrained by head halted. Food, water and mineral mixture were available ad libitum. Respiratory frequencies (RF) were measured by observing costal movements, rectal temperatures (RT ) were measured using a digital thermometer (Digitron, with an 8-cm flexible probe) and thermal balance was calculated according to procedures described by Silva et al., (2010). These measurements were carried out every day at 06:00, 10:00, 13:00 16:00 and 20:00h. Heat storage (HS) was calculated as described by McGovern and Bruce (2000). Sweat rate was measured at 15:00 hours using methodology described by Pereira et. al. (2010). Variables were analyzed according to a general linear model procedure with 2 fixed factors (breed and hour) and 1 nested factor (animal within breed). Results: Except for the cases of RT and HS, in the other variables no significant differences between the breeds were found. Despite the absence of significant differences in the thermal balance between breeds, there was a slightly tendency for a bigger acquisition of heat in Alentejana and a faster recovery in the Mertolenga after 16:00h. The sweating rates were not significantly different, with mean values of 271.5 and 286.3 (g.m-2.h-1) respectively for the Alentejana and Mertolenga. Respiratory frequencies were virtually equal between breeds. In RT there were significant differences between breeds. The Mertolenga has shown significantly lower RT at 16:00h and 20:00h, with 38,9ºC and 38,7ºC compared to 39,3ºC and 39,1ºC in Alentejana. The same trend was found in the HS at 16:00h and 20:00h with 0,018 and 0,016 W.m2 in Alentejana compared to 0,014 and 0,009 W.m2 in Mertolenga. Conclusions: The results show that both breeds present good heat tolerance. The sweating rate values of both breeds are very high and are quite similar to those found in tropical cattle breeds. However, Mertolenga shows slightly better thermal balance and evaporative heat loss (SR ans RF), which eventually may have contributed to the enhanced thermostability comparatively to Alentejana. The superior stability of the RT and particularly the lower HS suggest a higher heat tolerance of Mertolenga breed.