Part 2: Change the Things You Can - Irrigation in the Vineyard

Bill Gates is credited with proclaiming that he would “choose a lazy person to do a hard job.  Because a lazy person will find an easy way to do it.”  As it turns out, this sentiment doesn’t only apply to people, but seems to be a driving force behind all successful life on earth.  In the last post, I talked about how vines, when confronted with a drought, seek to conserve water by making less fruit and deepen their roots to increase the likelihood of finding water in the future.  Humans, after they started cultivating grapes, would try to increase the amount of fruit that their vines would produce by the easiest means necessary.  With limited technology, this entailed flooding the vineyard several times a year to simulate rainfall for the plants. 

Flood irrigation has two major drawbacks in terms of wine quality.  First, it is very difficult to control, so the vines are likely to receive too much water and, as a result, produce very large yields of watered-down, flavorless grapes.  Second, flood irrigation is only possible on flat land.  Many of the most famous wine regions are located in hilly locations.  Hills are more likely to have deep soil that the vines can send their roots into, while increasing the amount of sunlight hours the vine receives.  As a result, for centuries, the wine from vineyards that had been irrigated was inferior to that obtained from their dry and hilly brethren.

However, hillside vineyards in drought-prone areas weren’t without their own difficulties.  In addition to requiring more labor to successfully tend to hills, only those areas with sufficiently deep soil to enable correspondingly deep roots  would succeed when a drought struck.  If the soil was too thin to allow the grapes to create an extensive root system, those plants would have a poor chance of making it through a long drought.

To solve this difficult problem, Simcha Blass, an Israeli engineer, installed a drip irrigation system in Kibbutz Hatzerim in the 1960s.  This new type of irrigation, consisting of a latticework of hoses carefully pushing out water, drop by drop, to each plant played a significant role in the explosion of agricultural production that has occurred in the last half-century.  And because of its particular use to hilly terrain, wine regions all over the globe, but particularly in the New World, quickly adopted drip irrigation and, for a time, it became de rigeur for new plantings in California.

But Gates’s pithy observation is too narrow in its scope; efficiency is the main mechanism of evolution, not just a useful metric for corporations.  Vines will only dig their roots down deeply if they need to.  If they are provided with regular waterings close to the surface, they will grow more shallow roots in order to increase the chance of collecting that water.  The result is a vine that is dependant, and that is actually less drought tolerant than it would have been without any human intervention.

Next time, why there is a push to return to dry farming, and how it isn’t as simple as turning off the water.