868 research outputs found

    Will policy support for organic farming be justified in the future? The environmental impacts of organic farming

    Get PDF
    Introduction: In the European Union, organic farming has experienced a dynamic development in the 1990s, in part debited to financial support from agricultural policy measures. The most commonly used argument in support of organic farming is its positive environmental effects. However, support of organic farming practices on those grounds is only justified if these actually result in less negative environmental impacts than conventional farming. Stolze et al. (1999) reviewed existing research results up to 1997 on this topic and compiled a qualitative comparative evaluation based on an adapted OECD environmental indicator concept for agriculture (OECD 1997). On a per hectare basis, organic farming showed to be less detrimental with respect to most indicators than conventional farming. This paper will evaluate new evidence on the issue, taking results on a per output basis and the most recent developments in general EU agricultural legislation and organic standards into account. Materials and Methods: The OECD set of environmental indicators for the agricultural sector adapted by Stolze et al. (1999) is used. Based on a literature review of research results compiled between 1997 and 2002 a qualitative assessment is given for the following indicator categories: i) ecosystem, ii) natural resources (soil, ground and surface water, climate and air), iii) farm input and output, iv) animal health and welfare. The effect of recent developments in general agriculture EU legislation and organic standards on the relative benefits of organic farming is evaluated to assess if conventional agriculture is approaching organic agriculture due to tightening general legislation. Additionally, the option of achieving beneficial effects on some indicator categories when combining organic production with a targeted management of non-productive areas is reviewed. Results and Discussion: Organic farming seems to perform better than conventional farming with respect to all considered indicators, but large differences exist between indicators. New evidence permitted the evaluation on a per output basis for some indicators. This changes the final qualitative assessment for some indicators or indicator categories compared to the results of Stolze et al. (2000). Recent developments in EU legislation on agriculture in general do not seem to fundamentally change the relative assessment of the environmental impacts of organic in comparison to conventional agriculture. However, some important developments are not yet reflected in research results, e.g. the EU organic animal husbandry standards (European Commission 1999) which were implemented only in the year 2000. Conclusions: Support to organic farming is justified due to its positive environmental effects. However, the relative benefits must continue to be monitored in the light of current developments in agricultural legislation and organic standards. Cost-benefit analyses of the environmental effects of organic farming support in comparison to other agri-environmental measures and conventional farming are needed

    Time-crystalline behavior in an engineered spin chain ?

    Get PDF
    Time crystals appear when systems display a commensurate spontaneous breaking of the discrete time translational invariance imposed by an external periodic drive. No consensus on the definition has been reached as yet, but important aspects comprise robustness against small variations of the parameters and the initial quantum state. Often, disorder and interaction are thought to be essential ingredients for the occurrence of time crystals. We study a finite-length polarized XX spin chain engineered to display a spectrum of equidistant energy levels without drive and show that it keeps a spectrum of equidistant quasienergies in Floquet theory for a large variety of periodic driving schemes. This interesting behavior is explained by mapping the XX spin chain with N+1N+1 sites to a single large spin with S=N/2S=N/2 invoking the closure of the group SU(2). For suitably tuned parameters this system realizes time crystals of various periodicities for \emph{all} initial states. The robustness against variations of the parameters is also discussed. Thereby, we establish a clean system without interaction which can display the phenomenon of time crystallization.Comment: 17 pages, 5 figures. Title changed. Extended discussion of disorder effects. Accepted for publication in Phys. Rev.

    Environmental impacts of organic farming in Europe

    Get PDF
    Organic farming has become an important element of European agri-environmental policy due to increasing concern about the impact of agriculture on the environment. This book describes in detail the environmental and resource use impacts of organic farming relative to conventional farming systems, based on a set of environmental indicators for the agricultural sector on a European level. The policy relevance of the results is also discussed in detail

    A policy relevant assessment of the environmental impacts of organic farming

    Get PDF
    Organic farming has become an important aspect of European agri-environmental policy. Since the implementation of EC Reg. 2078/92, the EU promotes organic farming based explicitly on its positive effects on the environment. The objective of this paper is to contribute to a better understanding of organic farming's effects on the environment in comparison to conventional farming and to discuss the policy relevance of these issues. For this purpose the OECD set of environmental indicators for the agricultural sector has been adapted, taking into consideration only those indicators that are directly affected by the system of organic farming, as are the indicator categories ecosystem, natural resources, farm input and output, and health and welfare. Based on a survey of specialists in 18 European countries (all EU-member states plus NO, CH, and CZ) using a structured questionnaire and an extensive literature review, a conclusive assessment is given for each of the indicator categories. For most of the chosen indicator categories organic farming performs better than conventional farming on a per ha basis. These results are discussed with respect to their policy relevance. An increase in the area of organic farming would clearly improve the environmental performance of agriculture, as long as food production level is not a limiting factor. The question of whether there are other agri-environmental means of achieving a desired level of environmental performance that might be cheaper for society than organic production is discussed. It is concluded that the support of organic farming can be a useful part of the agri-environmental tool box, however, other, more specific instruments are also needed. Organic farming seems especially useful if broad environmental concerns are to be addressed

    Using Eco-schemes in the new CAP: a guide for managing authorities

    Get PDF
    This guide has been developed primarily for policy makers and Member State officials involved in the national and regional programming processes of the CAP Strategic Plans (CSPs). This process might involve different administrative levels (national, regional, local), different political fields (agriculture, environmental, food and health ministries), different public bodies (paying agencies, environmental agencies, rural development offices) depending on the administrative setting of each MS. In addition, the guide provides support to other stakeholders and practitioners from the public and private sectors and civil society (including agricultural, environmental, food, health and consumer NGOs), with a direct or indirect involvement in the programming and evaluation process of the CSPs. Since these new plans will have a strong impact on MS environments, agricultural sectors, rural areas, etc., the engagement of all stakeholders will be an important asset for supporting an effective implementation of the CSP objectives. There are many others with potential interests in the contents of this guide. EU citizens have demonstrated their increasing interest in the contents of the CAP objectives and policy framework, as demonstrated both by civil society initiatives and consumption decisions. The contents of this guide may therefore also be of interest to other societal actors with interests in agricultural and environmental policies, such as researchers, journalists, trade unions, and civil society organizations. However, the guide is intentionally more focused on the technical needs of those involved in CSP development and implementation

    Opportunities for farming in alpine countries – pathways to truly grassland-based beef and milk production in Austria and Switzerland

    Get PDF
    Farming in the alpine countries of Austria and Switzerland fulfils important economic, socio-cultural and ecological functions for society. However, even though both Austria and Switzerland have increasingly focused their agricultural policy towards ecology, in both countries negative environmental impacts of agriculture still have to be reduced massively

    Dynamics of Semi-infinite Quantam Spin Chains at T = ∞

    Get PDF
    Time-dependent spin autocorrelation functions and their spectral densities for the semi-infinite one-dimensiona ls=1/2 XY and XXZ models at T=∞ are determined in part by rigorous calculations in the fermion representation and in part by the recursion method in the spin representation. Boundary effects yield valuable new insight into the different dynamical processes which govern the transport of spin fluctuations in the two models. The results obtained for the XXX model bear the unmistakable signature of spin diffusion in the form of a square root infrared divergence in the spectral density
    • 

    corecore