25 seconds of your time could help a PhD student in need. There’s a 3-question survey at the bottom of this post. Do me the favor of answering it when you’ve finished reading? Thanks!
If your usual reaction to scientific research involves muttering about taking things out of context, take heart. Historians will look back on our time and call it the era of systems. After a century or so of studying factors in isolation, wine research is now full of studies trying to put them back together again. You’d expect research on terroir to be at the front of that move, and it is. New research out of Friuli in northern Italy is a good example, tying soil type and root structures together with wine quality. Their findings – that wines have the most character when vines can develop large roots through the full soil depth – aren’t shocking, but it’s one more tally mark on the “soil structure matters” side of things.
The researchers found 14 vineyards on different soil types, all Friulano* (same clone, same rootstock), a white variety common in the region, all between 15 and 20 years old, and all pruned and cultivated in the same way with herbicided undervine strips and ground cover between the rows. And then they got busy. They used some pretty elaborate apparatus to measure soil water content. They dug a lot of holes to investigate soil structure. They measured transpirable soil water, reflecting not just how much water is in the soil but how tightly the soil is holding on to that water and how available it is to vines. It’s been shown that that measure corresponds to leaf water potential, which shows how well-hydrated the vine is and, indirectly, how well it’s able to take up water from the soil. They dug three meter-deep trenches in every vineyard to document the full root structure. They did this for three years, and each year they made 200 kg batches of wine, then had a trained panel taste them yearly for three years after bottling (the wines were made in 2006-2008).