Research on biodynamic vineyard methods

Manuela Brando de Lachapelle, a researcher at the Barons de Rothschild Lafite estates, studied the effects of biodynamic preparations on vineyards at Château Lafite Rothschild in Pauillac, France, from 2022 to 2024. Her work, guided by professor Laurence Geny-Denis at the University of Bordeaux, compared organic vineyard management with organic methods enhanced by biodynamic treatments 500 and 501, applied nine times a year.

Study's three main focus areas

The research examined three aspects: the growth of the vine's vegetative parts, the reproductive development of the plant, and the texture of grape skins. The vineyard is fully organic, using copper, sulfur, and plant infusions, with biodynamic preparations added to specific areas starting in 2017.

Biodynamic effects on vine growth

Vines treated with biodynamic preparations produced fewer phyto-mers, which are small plant structures with stems, leaves, and clusters. They also showed signs of stronger water constraints but without visible stress, suggesting improved water use efficiency. In the reproductive phase, more flowers and inflorescences were observed, though the rate of fruit set was higher in the biodynamic group, leading to similar cluster and berry counts.

Impact on grape quality and wine tasting

Biodynamic treatments resulted in smaller berries and looser clusters, with a yield difference of less than 10%, which did not affect overall measured yields. Grape skins were found to be more resistant to botrytis, a fungal disease, with 69% of biodynamic berries unaffected after contact with the fungus, compared to 89% in the control group. Tasters could distinguish biodynamic wines from organic ones in a triangle test six months after bottling, but the difference faded after 18 months.

Contrasting findings from Swiss research

A 2023 study by Markus Rienth at the school of Changins in Switzerland found no significant differences in vine physiology, yield, grape quality, or soil properties after five years of comparing organic and biodynamic methods on a chasselas vineyard. His results aligned with previous research, though variations in experimental design may explain the differing outcomes.

Long-term German study on biodynamic methods

An eighteen-year trial on riesling vines in Germany, led by Johanna Döring, found that organic and biodynamic vineyards had lower average yields than conventional ones. However, biodynamic vineyards performed better during hot, dry vintages. No major differences were found in vine performance or grape quality, except for slightly lower phosphorus content in biodynamic leaves. Döring suggested that higher organic nitrogen levels in biodynamic harvests might explain the resilience.

Explanation of biodynamic preparations

Biodynamic preparations are numbered, with 500 being cow manure applied to the soil and 501 being cow horn silica applied to plants. Other preparations include CBMT, a compost made from cow manure, and others like 502 (yarrow), 503 (chamomile), 504 (nettle), 505 (oak bark), 506 (dandelion), and 507 (valerian).