ifoam'96 ifoam'96
Book of Abstracts
11th IFOAM Scientific Conference
11-15 August 1996, Copenhagen, Denmark
EcoWeb Denmark


Quality of Products from Different Farming Systems (DOC-Trial).W27/P3

Alfoeldi, Thomas1; Besson, Jean-Marc2; Dubois, David3; Maeder, Paul1; Niggli, Urs1; Spiess, Ernst2.

1) Research Institute of Organic Agriculture, CH-4104 Oberwil, 2) Institute of Environmental Protection and Agriculture, CH-3097 Liebefeld-Bern, 3) Swiss Federal Research Station for Agroecology and Agriculture, CH-8046 Zurich.

Consumers of organically grown food are expecting a higher product quality. There are numerous studies on the quality of conventionally and organically grown products. However, comparisons were rarely conducted with the same variety being produced under similar conditions. Since 1978 we compare three farming systems biodynamic, organic and conventional in a long-term field trial (DOC trial). The systems differ mainly in fertilization and plant protection. Tillage, varieties and crop rotation are the same for all systems. The seven year crop rotation consists of potatoes, winter wheat, beetroot, winter wheat, barley and two years of grass-clover. This presentation will focus on quality parameters of winter wheat and beetroots with regard to chemical, biochemical, physical and holistic methods. Wheat quality assessed by its content in minerals, amino acids and protein as well by its technological quality (baking capacity) was not affected significantly by the different treatments. The beetroots of the biological farming systems had a lower potassium and nitrate content, whilst phosphorus, calcium and magnesium were not affected. In a cluster analysis comprising 12 chemical parameters it was possible to group correctly the unfertilized control, the mineral control, the conventional system and both biological systems. Since 1987 we included a holistic method for quality visualisation (picture developing method) in our quality investigation program. This method allowed for a distinct grouping and identification of encoded samples of wheat and beetroots (picture creating, interpretation and classification by U. Balzer-Graf, CH-Wetzikon). However, this holistic approach needs further explanation. First years results showed that a distinction between organically and conventionally grown wheat was possible by the use of isoelectrical focussing to fractionate esterases (method and analyses by U. Hauri, CH-Basel).