At the Geisenheim Research Centre (Rheingau), the Foundation Ecology & Agriculture (SÖL) presented the first exciting results from a comparative study that is still in progress. Next door, Peter and Angela Kühn reported on their practical experience of biodynamic wine-growing.
The interest in the event - it was attended by 60 people, mainly winegrowers - was so great that it had to be held twice.
The study started in 2006 compares integrated, organic and biodynamic wine-growing on 0.8 hectares. The test plot, on which only Riesling vines are grown, is divided into sections of four rows each. In the first third, the rules of integrated wine-growing are applied, with the use of artificial fertilizer, herbicides and synthetic pesticides. The other two thirds are cultivated according to organic or biodynamic principles. Both of these variants are fertilized with manure compost. Weeds growing under the vines are removed mechanically. Cow horn manure and horn silica are also used on the biodynamic plots, with these biodynamic preparations being added to the compost.
The project leader is Georg Meißner, who is currently writing his dissertation on the study.
The study will then be continued. "Since comparing systems naturally makes more sense if it is long-term," says Professor Randolf Kauer, who is in charge of organic wine-growing in Geisenheim and is pleased with the increasing interest among students. "Of the roughly 100 students who start studying viticulture here every year, 50-60 opt for specializing in organic wine." All the other subject areas are also involved in the study. In the laboratory, for example, comparative measurements are undertaken. Grapes and berries are examined and compared for size, weight, sugar and acid content and many other parameters. The wines are analysed just as meticulously, and this is followed by sensory evaluation.
First preliminary results are available
The organic plots produce in general less volume - less wood, less leaf mass and about 20% less weight of grapes. This means, on the other hand, that the foliage is less dense and the grapes are less compact, both factors helping to counteract fungal attacks. "So, despite not using botrytis fungicides, infestation in the organic plots is lower than in the integrated plots," concludes Georg Meißner.
The situation is similar regarding sour rot. In the case of almost all the parameters, the effects on the biodynamic plots are more pronounced than on the organic plots.
Peter and Angela Kühn then gave some insights into the practical running of a biodynamic winery.
The Peter Jakob Kühn winery in Oestrich consists of 20 hectares of vines, of which 3 hectares are steep slopes. The Kühns converted all production to organic and biodynamic wine growing in 2004, after having phased out the use of artificial fertilizers and herbicides in the years preceding conversion.
They regard making biodynamic compost as very important. They produce the preparations themselves on a specially selected meadow plot. "I regard the preparations as compensation for the diversity that has been lost in nature and on the farm," explains Peter Jakob Kühn.
It's far from being an ideal situation, but that doesn't worry him, because his motto is "the way is the goal". |
