10,373 research outputs found
Assessing the ecological soundness of organic and conventional agriculture by means of life cycle assessment (LCA) - a case study of leek production
Purpose – Sustainable agriculture implies the ability of agro-ecosystems to remain productive in the long-term. It is not easy to point out unambiguously whether or not current production systems meet this sustainability demand. A priori thinking would suggest that organic crops are environmentally favourable, but may ignore the effect of reduced productivity, which shifts the potential impact to other parts of the food provision system. The purpose of this paper is to assess the ecological sustainability of conventional and organic leek production by means of life cycle assessment (LCA).
Design/methodology/approach – A cradle-to-farm gate LCA is applied, based on real farm data from two research centres. For a consistent comparison, two functional units (FU) were defined: 1ha and 1?kg of leek production.
Findings – Assessed on an area basis, organic farming shows a more favourable environmental profile. These overall benefits are strongly reduced when the lower yields are taken into account. Related to organic farming it is therefore important that solutions are found to substantially increase the yields without increasing the environmental burden. Related to conventional farming, important potential for environmental improvements are in optimising the farm nutrient flows, reducing pesticide use and increasing its self-supporting capacity.
Research limitations/implications – The research is a cradle-to-farm gate LCA, future research can be expanded to comprise all phases from cradle-to-grave to get an idea of the total sustainability of our present food consumption patterns. The research is also limited to the case of leek production. Future research can apply the methodology to other crops.
Originality/value – To date, there is still lack of clear evidence of the added value of organic farming compared to conventional farming on environmental basis. Few studies have compared organic and conventional food production by means of LCA. This paper addresses these issues
O direito autoral na sociedade da informação.
Com o avanço das tecnologias de informação e comunicação (TIC), configura-se um novo cenário que favorece o compartilhamento e a construção coletiva de conhecimento, especialmente em espaços virtuais. Na sociedade da informação, o paradigma é a participação, a colaboração e a troca de conhecimento. Por isso, a questão dos direitos autorais precisa ser melhor refletida e debatida, para que o conhecimento possa circular e promover inclusão social. Algumas iniciativas têm surgido, principalmente por parte da comunidade de desenvolvedores de software de código aberto e de setores voltados ao entretenimento - como música, jogos e filmes, que adotam o modelo colaborativo de produção e buscam tornar disponível a sua produção ao maior número de pessoas possível, aproveitando os recursos tecnológicos para reduzir os custos de trabalhos produzidos em rede. Entretanto, os aspectos econômicos que envolvem o tema têm representado entraves a essa disseminação. Neste artigo, vamos apresentar dados que mostram porque o assunto é tão polêmico e merece maior atenção das políticas públicas, no sentido de democratizar o acesso ao conhecimento e favorecer o processo de educação
Coletânea de resumos de artigos técnico-científicos publicados pela Embrapa Arroz e Feijão e parceiros - 2005.
Contém os resumos dos artigos publicados no ano de 2005 pela Embrapa Arroz e Feijão e parceiros, nos mais variados periódicos nacionais e internacionais.bitstream/CNPAF/26621/1/doc_217.pd
NUMERICAL ANALYSIS OF THE NATURAL CONVECTION IN HORIZONTAL ANNULI AT LOW AND MODERATE Ra
The natural convection at low and moderate Rayleigh numbers (Ra) incylindrical horizontal annuli with imposed temperatures in both surfaces isnumerically studied. This flow inside concentric cylinders classic configuration has a wide range of practical and technological applications, which justifies its growing studies efforts. In this work, the governing equations are discretized by the volume finite technique over a staggered grid, with second-order accuracy in space and time. The flow pattern is presented by several Rayleigh numbers, with an analysis of the heat transfer coefficient and flow properties. Furthermore, a three-dimensional field is shown at a moderate Ra number. The results showed a good agreement with the experimental data
Teor de fósforo em feijão caupi (Vigna unguiculata L.), cultivado em diferentes sistemas de manejos.
O presente trabalho teve como objetivo avaliar a influÍncia do sistema de manejo de solo nos teores de fÛsforo em plantas da cultivar R-17 gurguÈia, de ciclo curto (45 dias
- …