Vineyard weed control... and introducing the spader, our newest toy
May 14, 2010
At this time of year, it's essential that we get into the vineyard and complete the long process of knocking down the vineyard weeds so that they don't steal water and other scarce resources from the vines. This is a multi-stage process that takes us months and involves variously mowing, disking and burning the cover crop, using our tournesol cultivator and hand-hoeing among the vines, and even rototilling to smooth out the areas we've chewed up. The rain we received this winter makes the process longer, both because it contributed to the most amazing cover crop growth we've ever seen and because we kept getting rain in April that forced us out of the vineyard for days at a time. Even after weeks of work, there are still sections of the vineyard where the weeds and wildflowers are more visible than the vines, like the section of Grenache Blanc below nearly swallowed by vetch:
Our main tool for turning over the soil has been the disker (which anyone in a farming district will be familiar with). It digs down 6-8 inches and turns the cover crop into the topsoil. This is a quick and inexpensive way of working the soil. Two photos are below, one of the overturned soil and another of the disks themselves:
While the disker handles the cover crop between the rows, the tournesol can weed within the vine rows. It accomplishes this challenging task with the aid of rubber sensor arms that stick out in front of the sunflower-shaped cultivator heads that give the tournesol its name:
One problem with the disker is that it doesn't penetrate that deeply, and can leave a hardpan of clay six to eight inches below the surface. A second problem is that it leaves the soil pretty chewed up and uneven, which complicates future work in the vineyard. Enter the spader, which we just got and put into action this week. It works with a series of spade-like blades attached to a cam system that individually delve into the soil and turn it over.
Watching the spader get to work is impressive. The dirt comes out so smooth it looks as though it's been rototilled. Two similar rows are below, the left disked and the right spaded:
Even more impressive is how it can, in one pass, turn a vineyard row from winter-scruffy to summer-clean. As you can see:
Another advantage of the spader is how deep it penetrates. Neil Collins, who is our vineyard manager in addition to our winemaker demonstrated, reaching his arm elbow-deep into the newly-turned dirt:
As you can probably tell, we're excited. And the biodynamic consultant who we're using to help us as we transition 20 acres to biodynamic is a big fan: he reported that the deeper tilling, the reduced soil compaction and the better penetration of nutrients and water resulted in a 40% increase in crop (at higher quality) at the last vineyard where he saw one introduced.