Satellites and terroir

Interesting piece on Wine Anorak website highlighting some of the pros and cons of precision viticulture. It is one of the terms that irrationally gets my hackles up like “precision bombing”. The wine world is besotted with the latest technology, with an almost voodoo belief in its powers to improve outcomes.

http://www.wineanorak.com/blog/index.htm

I am always somewhat sceptical about a scientific development (I think the term is misapplied here) which claims to be a replacement for common sense. You wouldn’t have a relationship with someone based on a photograph (no matter how attractive the photo). Satellite imagery is effective only at the most peripheral level.  There is no substitute for being up close and personal in the vineyard. It may sound like a sweeping romantic assertion but the knowledge of generations is worth any amount of satellite pictures.

Most very large vineyards, in any case, are effectively monocultures in regions where the mesoclimate is constant and microclimate is largely an irrelevance (by virtue of the fact that man has shaped the environment through intensive farming). In other words 300ha planted on the plains will yield even-ripening year after year after year. Smaller, discrete vineyards, however, perhaps planted on slopes or in forest clearings, are more influences by the subtleties of terroir, and consequently have to be assessed with a more personal “tactile” approach. Only by daily examination of the grapes and making due adjustments (leaf-plucking, canopy management) can one realise the potential of every vine. Intense triage is also necessary; not every vine is the same age (hence naturally reduced vigour) and microclimatic variations can occur over the space of a few metres. I have been in a vineyard in western Spain where grapes ripen differentially on a vine by vine basis.

Jamie writes:
Satellite imagery at appropriate points in the growing season, using a range of wavelengths of light, can be used to generate what’s called an NDVI (normalized differential vegetation index, so effectively what is being measured is vigour), and with some computer processing, you can make a map of your vineyard showing the homogeneous blocks (that is, the ones that are similar). If these are similar year-on-year, you can then treat these blocks differently, and pick them at different times. The result is improved quality. It’s terroir in action.

Good vignerons already geologically map their vineyards and observe patterns year on year.  So-called zoning is easy – you only have the look at the vegetative growth of the vines to discern comparative vigour. Who understands terroir better than the man or woman who stands with the soil on their shoes and the grapes in their hands?

However, for every pattern or rule there are exceptions. Recently there was a vintage in central Otago where the styles of the wines flipped. The warmer vineyards produced the lighter, more elegant wines, whilst those situated in the cooler sub-regions produced more powerful, alcoholic efforts. The beauty - and difficulty - is always rising to the challenge – and knowledge is for nought in the face of the vagaries of the weather.

Terroir is the summation of geological and climatic factors that makes the wine the way it is. It does not take into account the pattern of each individual vintage; and computer processing of satellite information would be constantly changing. The microcosmic subtleties of vineyard activity are best surveyed with the naked eye rather than a telescope no matter how finely it may be calibrated. Reality is something you can touch, not a projection you make from computer data.

So, precision viticulture, (perhaps a bad name because viticulture should resist the notion of being a precise art) is not necessary for the big monocultural estates and equally pointless for the small individual vineyards. Jamie suggests that it might be a tool for medium-size commercial enterprises where there is natural variability in the vineyard. I would say that if you have to arrive at basic knowledge through long distance analysis you remove yourself from the very process of learning that makes you a better vigneron. If science teaches us anything it is to expect the unexpected.