357 research outputs found

    DEVELOPMENT OF THE UTILIZATION OF PASTORAL LAND IN THE EU 25 AFTER 2003

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    Farming systems based on products of roughage feeders are a vital part of the EU agricultural production. Up to the CAP reform in 2003 the EU promoted these systems via a wide variety of measures. This paper highlights the different impacts European, national and regional support measures have on the utilization of pastoral resources across the EU-25. Based on an expert survey and a literature review the paper summarizes the expected developments of pastoral farming systems across the EU.Pastoral Systems, EU, 2003 CAP Reform, Enlargement, Land Economics/Use,

    Impact de la densité de semis et de la fertilisation azotée sur le développement de Rumex obtusifolius L. en cultures de céréales d'hiver conduites en agriculture biologique

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    The control of Rumex obtusifolius L. (broad-leafed dock) is very important in organic farming systems. Indeed, concerns about managing this weed without the use of herbicides is one of the major factors limiting the uptake of these systems by conventional farmers. Against this backround, we analyzed the impact of two management practices on the development of R. obtusifolius populations in two winter cereal trials: spelt (triticum spelta [L.] thell.) and triticale (xtriticosecale [A.Camus]Wittm.). The management factors were sowing density (SD) and nitrogen fertilization (NF) at the tillering stage. The results showed that and increase in SD and NF led to stronger crop growth and better soil coverage by the end of sping, demonstrated by a significant decrease in photosynthetic active radiation (PAR) at soil level. However, although there was an SD effect, it was too weak in April to restrict an increase in R. obtusifolius populations through the recruitment of new R. obtusifulius plants. An increase in R. obtusifolius population density was also linked to an increase in the NF level, illustrating the nitrophilic character of this weed. Although an increase in SD and NF at the tillering stage led to a higher canopy density, these two practices failed to reduce R. Obtusifolius density in the cereal crops. Nevertheless, cereal yields were shown to be maintained or improved. Our results indicate that, even when combining weed harrowing and some cultural weed control methods, this perennial weed is difficult to control

    Prediction of Red Clover Content in Mixed Swards by Near-Infrared Reflectance Spectroscopy

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    Because of the legume fixation capacity, their high protein content, digestibility and intake characteristics, more and more attention is paid to grassland clover content. In field experiments, clover content must often be determined, for example to quantify nitrogen flux or the best practices to manage such species (Stilmant et al., 2004). However hand sorting of clover and grass, even if accurate, is time-consuming and has a high labour cost. In comparison, accuracy of visual estimation of clover content, directly in the field, varies according to training and experience. Near-infrared reflectance spectroscopy (NIRS) has been proposed as a method for the rapid determination of sward botanical (Petersen et al., 1987; Pitman et al., 1991) and morphological composition (Leconte et al., 1999; Stilmant et al., 2005). This paper describes the performance of a NIRS calibration developed to characterise red clover (Trifolium pratense) content when associated to different grass species and this at different phenological stages

    The Use of Near Infrared Reflectance Spectroscopy (NIRS) to Follow the Leaf/Stem Ratio of Legumes During Drying

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    Legume-rich mixed swards allow the production of a high quantity protein-rich forage with low nitrogen input. Nevertheless, during hay or silage making, dry matter losses as high as, 40 and 25 % have been recorded (Ciotti & Cavallero, 1979; Stilmant et al., 2004). These losses have mainly been linked to the high sensitivity to physical loss of legume leaves during drying. The development of a tool to characterise leaf losses or leaf/stem ratio during drying will help us to define the technical approach to reach the best compromise between quality loss reduction and good pre-wilting of legum-rich mixed swards. The aim of the present work was to test the potentialities of near infrared reflectance spectroscopy (NIRS) to quantify legume leaf/stem ratio in mixed grass-legume swards. The mixtures tested were perennial ryegrass-white clover (PR-WC), perennial ryegrass-red clover (PR-RC), timothy-red clover (T-RC) and cocksfoot-lucerne (C-L) swards. This technique has been successfully used to quantify leaf/stem ratio in pure perennial ryegrass swards (Leconte et al. 1999)

    Systemic analysis of production scenarios for bioethanol produced from ligno-cellulosic biomass [abstract]

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    Defining alternatives for non-renewable energy sources constitutes a priority to the development of our societies. One of these alternatives is biofuels production starting from energy crops, agricultural wastes, forest products or wastes. In this context, a "second generation" biofuels production, aiming at utilizing the whole plant, including ligno-cellulosic (hemicelluloses, cellulose, lignin) fractions (Ogier et al., 1999) that are not used for human food, would allow the reduction of the drawbacks of bioethanol production (Schoeling, 2007). However, numerous technical, economical, ethical and environmental questions are still pending. One of the aims of the BioEtha2 project, directed by the Walloon Agricultural Research Centre, is to define the position of bioethanol produced from ligno-cellulosic biomass among the different renewable energy alternatives that could be developed in Wallonia towards 2020. With this aim, and in order to answer the numerous questions in this field, the project aims at using tools and methods coming from the concept of "forecasting scenarios" (Sebillotte, 2002; Slegten et al., 2007; For-learn, 2008). This concept, based on a contemporary reality, aims to explore different possible scenarios for the future development of alternative sources of energy production. The principle is to evaluate, explore, possible futures of the studied problematic, through the establishment of possible evolution trajectories. We contribute to this prospective through a systemic approach (Vanloqueren, 2007) that allows lightening the existing interactions within the system "ligno-cellulosic biomass chain" without isolating it from its environment. We explain and sketch the two contexts needed to identify primary stakes. The global context includes inter-dependant and auto-regulating fields such as society, politics, technology and economy. These four fields influence each part of the "chain" with specific tools. However, the interest and possible action fields lay within the intermediary context representing the "resources" such as agriculture, forestry, "driving" elements such as mobility, mediation elements such as territories and environment and concurrent elements such as non-cellulosic biomass, the energy mix and the non-energy valorization

    Dike-break induced flows: a simplified model

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    A simplified model for the prediction of the steady-state outflow through a breach in an inland dike is presented. It consists in the application of the mass and momentum conservation principles to a macroscopic control volume. A proper definition of the shape of the control volume enables to take into account the main characteristics of the flow and thus to compensate for the extreme simplification of the space discretisation of the model. At the breach, a relation derived from the shallow-water equations is used to determine the directions of the flow. Developments have been guided by numerical simulations and results have been compared to experimental data. Both the precision and the application domain of the simplified model are found satisfactory
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