The role of mechanization in zone/terroir expression

Vineyard mechanization will be addressed in this review paper primarily as related to pruning and harvesting since these operations typically require a great deal of the total yearly labour demand (Intrieri and Poni, 1998). However, to be able to define how mechanization interacts with “terroir”, a rigorous definition of the latter term is needed.
James Goode (www.wineanorak.com) states that “terroir” must be reserved solely to describe the physical environment in which the grapevine grows – that is the soil type, microclimate and slope of a defined area. However, we would rather prefer the following broader definition; “Terroir: the ecology of a wine. The total, inter-related environment wherein a grapevine is cultivated for the purpose of making wine. Key factors include, but are not limited to, cultivar type, soil, climate, vineyard location, planting density, training system, pruning philosophy & the cultural and social milieu wherein the whole enterprise takes place”. In fact, we think that also choices like vine spacing or training system define a “terroir”; if we imagine a high-density vineyard trained to goblet in the south of France to be pulled out and replanted at wider spacing with a strikingly different trellis, could we say that the wine coming from that vineyard is still the expression of the same “terroir”? We doubt it.
Once “terroir” has been generally defined, it has to be verified if the definition holds for both Old and New World. To simplify, it can be stated that Old World terroirists aim to make wines that express the “typicity” of the vineyard site by putting a major emphasis on soil effects; in the New World the “terroir” effect has been somewhat disregarded and it is still viewed, under a more pragmatic way, as a route to improved quality.
Here, another important question rises: are both Old and New World facing viticultural changes that will soon affect the relationship between “terroir” and mechanization? The answer is in the affirmative although these changes have different rationales. The increasing cost of hand labour, often associated with the difficulties of finding skilled workers (mostly for winter pruning), will indeed produce in the Old World an increased interest in mechanized grape production systems. It is a trend that will be hastened if this process is paralleled by lower wine prices on the market.
The New World is already highly mechanized (Australia is the appropriate example here). This high degree of mechanization is facilitated, among many factors, by vineyard size. It is known that some New World vineyards are hundreds of hectares in size, while some in the more traditional parts of Europe are fractions of a hectare. However, this also means that when very large vineyards are machine-harvested in Australia, different “terroirs” are likely blended and their individual winemaking potential is diluted or dispersed.
Given that wine quality is enhanced by fermenting homogeneous lots of fruits and that variation in batches of delivered grapes is mainly due to soil (Smart, 1996), several large companies in Australia are tackling soil mapping to spot zones of similar “Readily Available Water” or are considering precision viticulture (Morris, 2001). Using global positioning systems (GPS) in association with geographical information systems (GIS) makes it possible to divide vineyards into management grids, each of which is quantified and treated separately. Technology is already available (Robertson, 2000) to build sensors that record specific information from each vine in order to formulate maps for vigour, °Brix, phenols and so forth. Of course, this has an impact on mechanization since machineries are being modified to incorporate computerized monitoring devices and sensors. A pertinent example is GIS driven mechanical harvesters, which can adjust speed or slapper frequency according to the maturity gradient along a vine row. Quite paradoxically, it appears that the New World is moving quickly towards these techniques to fill the gap with the Old World in terms of “terroir” expression.
Mechanization clearly interacts with many of the key factors listed within the broader definition
of “terroir” (namely vineyard location, planting density and training system). Yet the meaning of “terroir” nowadays is still being associated with the general concept of “recognizable” grape quality. Therefore, the interaction between vineyard mechanization and “terroir” can probably be analyzed from two basic viewpoints:
A) How does the concept of full vineyard mechanization fit with maintenance of high quality requirements? This is a crucial issue. Indeed, still widespread in the Old World viticultural countries, such as Italy, it the “rule of thumb” whereby a fully mechanized vineyard cannot give top quality and that only the patient hand labour can actually achieve the “gold standards”;
B) Is mechanization a useful tool to reach maximum vineyard efficiency? A reasonable definition of vineyard efficiency is reaching the highest yield at the “desired” or “salable” quality at the lowest production costs.
The B statement broadens the area of interaction between mechanization and “terroir”. Here a suitable example is provided in Figure 1, showing the fractional distribution (year 2003) of exported Italian wine as a function of price per litre (Pedron, 2004). The narrow pyramid shows that only 2.9% of the total value is sold at prices higher than €6/l, whereas more than 65 % of the value goes to prices lower than €3/l. Therefore, restricting the term “terroir” to the top price would basically eliminate the need to investigate the interaction between “terroir” and “mechanization” since those bottles are quite likely coming from prestigious sites where labour cost is not, at least not yet, a priority. Clearly, even the lowest price rate can be representative of a “terroir” if the definition given at the beginning of this introduction holds.