Vineyard chemistry linked to soil and roots

Researchers have found that differences in Pinot Noir grape chemistry between two vineyards were associated with soil pH, manganese and the bacteria living around vine roots.

The study, published in the Journal of the Science of Food and Agriculture, found that changes in soil conditions and rhizosphere bacterial communities tracked with differences in amino acids and phenolic compounds in the grapes.

Rather than identifying a single cause, the researchers found a network of linked factors including soil pH, cation exchange capacity, exchangeable manganese and bacterial community structure.

The findings add to growing research into how conditions beneath the vines may help explain why grapes from different vineyards can develop distinctive chemistry. Amino acids are important for yeast fermentation, while phenolics influence colour, bitterness and astringency.

Although the study covered only two Pinot Noir vineyards, the researchers suggest that combining soil and microbial measurements could eventually improve precision viticulture and help growers better understand the factors shaping fruit composition.