THE ROOTS OF FINE WINE, PART 1
The autumn harvest has begun with the first bunches of grapes picked, sorted, shredded, pressed and placed in their respective fermentation vessels. We take this occasion not merely to as an opportunity to document what is going on around the farm, but to consider some of the principles involved in some today’s most cutting-edge ecological vineyard management practices as part of the ongoing process of reflection, evaluation and inspiration through which we learn from the best and grow towards our goals.
Winemaking begins in the vineyards, and the vineyards begin from the ground up. Terroir emerges from the interplay between climate, geography and biology situated in the atmosphere, geosphere and rhizosphere, respectively. Of all these factors, the community of microbes at home in the rhizosphere, surrounding the root zones of plants, is the most complex, and most delicate, element at play in determining the quality of any given vintage. It is sustained through a steady supply of carbohydrates exuded from the roots of plants, and destroyed through applications of fertilisers, insecticides, herbicides and fungicides — both chemical and organic — as well as through ploughing, which destroys mycelium networks and strips bare the green cover on whose work of photosynthesis all living soils depend. Due to these destructive practices an ever growing proportion of planet earth is passing through “the three stages of soil death” described by Emmanuel Bourguignon in The Destruction of Cultivated Land. Surprisingly to some, the words death and destruction are not used here in a metaphoric sense. Emmanuel and his parents Lydia and Claude, who together founded one of the most respected institutions in the world of viticulture, the Laboratory of Soil Microbiological Analysis (LAMS), have noted more organic activity in highly desertified areas in Tunisia than in some French or Spanish soils! They go on to note that from the 3.6 billion hectares of cultivable soils available around the world at agriculture’s dawn, 2 billion hectares have already been desertified.
Since the principles of good terroir are much the same as the principles of good soil everywhere, the methods for managing vineyard fertility is much the same as the methods of agroecology applied for a wide variety of crops around the world: continuous cover cropping instead of ploughing; compost, nitrogen fixing companion plants and organic fertilisers instead of chemical fertilisers; Integrated Pest Management instead of chemical or organic pesticides.
One special aspect about terroir is the relationship between the character of wines and the subsoil: the fact that grapevines are naturally adapted to mine for water and nutrients many meters deep means that a rich bouquet of minerals is drawn up through the subsoil strata by the roots. Misapplication of ploughing, weeding, irrigation and fertiliser encourages vines to develop shallow horizontal, rather than deep vertical roots, resulting in wines where terroir no longer plays a role. For this reason, so-called weeds are encouraged wherever good wine is made. “It is important to let the grass grow in the vineyard,” says Lydia Bourguignon. “With the grass the vines get competition for water and nutrients and because of that the roots are forced to find their way down to the subsoil.” If the producer thinks the grass competes too much with his vines, a lower planting density would be better than to forgo grass. But ideally, she says, you should have both high plant density and grass growing. “A great terroir can do it. Even if you do not have to go to excesses like 50,000 vines per hectare as some vineyards in Champagne had in the old days.”