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