FØJOII-29: Nature Quality in Organic Farming. Midterm Status Report 2003

The work is organised in five work packages (WP 1-5, Table A1). Since the start in July 2001 the following work has been accomplished: WP 1. Starting up seminar and the annual seminars have served as a successful platform for project planning and cross-cutting activities. The general project co-ordination and planning of field work and selection of case study areas has been stimulated both at these meetings and in separate meetings with the WP responsibles. The first cross-cutting (CC4) has been accomplished in close co-operation with WP 5 and all project scientists. A homepage for the project is now available. WP 2. Eleven case areas with high concentration of organic farmers have been selected and 347 farmers have been interviewed. A database holding this information has been constructed. Organic farms show a regional specialisation similar to conventional farms. At the regional level organic farms are concentrated in counties with a higher share of dairy farms. Within counties however, there are important local differences with other factors involved. A GIS-based method for case-area delimitation in the PhD landscape study has been developed. WP 3. Inventory data from 24 organic farms in two case areas with information on vegetation composition and arthropods has been analysed. New species for Denmark was found and arthropod indicators showed a good correlation to nature quality. Colonisation experiments showed that moss diversity is favoured by grazing and reduced by fertilisation. There was significantly higher plant diversity in hedges and field boundaries on organic farms than on traditional farms. This effect is evident after only 3-4 years of Organic Farming Period and further increased after 7 years WP 4. Data from the same 24 organic farms and experimental fields of Foulum and Flakkebjerg has been collected in 2002 and 2003. Soil fauna diversity is influenced by soil type, tillage intensity and fertiliser use as well as crop and grazing history. In the experimental plots soil fauna and surface arthropods only showed little response to fertiliser use and catch crops. A 10x10-km landscape has been digitised in the ALMASS landscape model and appropriate scenarios and crop rotations are under construction. WP 5. Results from the first project workshop (CC4) in 2002 on indicators for esthetical qualities show that a more professional use of the esthetical experience is difficult for many natural scientist. Serious illness has postponed work in 2003 but the final outcome of the work package is expected to be achieved

Nature quality in organic farming: A conceptual analysis of considerations and criteria in a European context

Nature quality in relation to farming is a complex field. It involves different traditions and interests, different views of what nature is, and different ways of valuing nature. Furthermore there is a general lack of empirical data on many aspects of nature quality in the farmed landscape. The present paper looks at nature quality from the perspective of organic farming, which has its own values and goals in relation to nature – the "Ecologist View of Nature". This is in contrast to the "Culturist View" characteristic of much conventional agriculture and the "Naturalist View" characteristic of the traditional biological approach to nature quality. This threefold distinction forms a framework for exploration of nature quality criteria in the farmed landscape. The traditional work on nature quality has mainly focused on biological interests based on a Naturalist View of Nature. In this paper we will explore how criteria for nature quality based on the Ecologist View can be developed and thereby feed into the ongoing discussion of the development of the organic farming practises. We suggest additional criteria for nature quality based on an Ecologist View of Nature: biodiversity; habitat diversity, extent and structure; functional integrity of habitats and agroecosystems; and landscape integrity, accessibility and experientiality. The larger set of Naturalist and Ecologist criteria can provide a wider and more balanced basis for developing nature quality indicators that are relevant in the farmed landscapes. This broader approach to nature quality is also expected to benefit the general societal discussions and decisions on farming and nature

Naturkvalitet i økologisk jordbrug – koncept og foreløbige resultater.

This paper presents shortly an ongoing project on the influence of organic farming on nature quality in a broad sense. This includes investigations of patterns of localisation of organic farming in relation to landscapes, biological diversity outside organic fields, ecosystem diversity and function of fields and landscapes in organic farming as well as perceptions and practices of organic farming. The aim of the project is to identify key components to ensure continuous development of organic farming towards a closer integration of nature quality with food production. Some preliminary botanical data are presented showing that nature on organic farms is dominated by very common competitive species also dominating uncultivated biotopes in conventional farming

Flora og insekter i hegn på økologiske og konventionelle bedrifter

The aim of the project was to compare flora and insect fauna of organic and conventional hedgerows and to study whether the drift of herbicides into hedgerows alone or in combination with differences in fertiliser application may explain any differences. The project consequently consisted of two parts, viz. collection of flora and insect data in existing hedgerows (multi-row hedgerows, age 10-15 years) on two soil types and an experiment in which a sown grassland vegetation was treated with combinations of glyphosate (0-25% label rate) and nitrogen (0-100 kg N/ha/year) as a simulation of the most important agricultural conditions having an effect on flora and insect fauna in different agricultural systems. In the experiment flora and insect fauna were studied for three years. In the hedgerows clear differences in the floral composition were found, with more plant species in hedgerows at organically grown fields than at conventionally grown fields, on both sandy and loamy soils. The insect fauna was correlated with the flora, but no clear differences were found between the two agricultural systems. Apart from the hedgerow flora, also the type of crop grown on the adjacent fields affected the abundance of herbivorous insects, especially bugs and weevils. In the experiment the effects of glyphosate and nitrogen treatments interacted strongly. In unfertilised plots the number of plant species decreased at increasing glyphosate dosages, whereas plant biomass was virtually unaffected, and litter biomass decreased. For plant and litter biomass the glyphosate effect increased at increasing fertiliser levels, i.e. there was a severe decrease in both plant and litter biomass as a consequence of glyphosate treatment. For numbers of plant species the interactive effect was opposite, as the glyphosate effect decreased at increasing fertiliser levels. Insect abundance and species numbers followed the picture seen for plant biomass, but with differences between insect groups

Mere natur i økologiske hegn

Hegn i Danmark forbindes i høj grad med læ. Specielt i Jylland har læhegn været af stor betydning for landbruget. I dag har hegnene en bredere betydning, men der er kun lille viden om naturværdierne. DMU har i en undersøgelse vist overraskende klare forskelle på især plantelivet i hegn på økologiske og konventionelle bedrifter

Naturindholdet i hegn på økologiske og konventionelle bedrifter

Many attempts have been suggested to reduce the impact of modern conventional farming on the environment and semi-natural ecosystems. One of the attempts has been to introduce organic farming, which is known primarily for the absence of pesticides and artificial fertilising. The objective of this paper is to present differences found in the spontaneous vegetation and associated arthropods of comparable hedgerows situated within organic and conventional farming systems. We found significantly more plant and moss species in organic hedges, both in the individual plots, the individual hedges and when comparing the farming systems. Six species (Brachythecium rutabulum, Cerastium fontanum, Ranunculus repens, Cirsium arvense, Sonchus arvensis, Plantago lanceolata) were found to be indicators of organic hedges. Arthropods were distributed in relation to the same parameters as the flora (mainly soil characteristics and farming practice). However, differences between the two farming systems were smaller than for plants. The occurrence of herbivorous groups as a total correlate significantly with the major plant gradients and weevils correlate significantly with grass lay fields beneath the hedges and organic farming. Psylloidae, Syrphidae and the weevils (Curculionidae) Ceutorrhynchus floralis and Apion virens proved to indicate organic farming