The article about how Bremer Family Winery is spending hundreds of thousands of dollars on trucking Valley soil to a new vineyard site in Angwin raises a big question ("Angwin winery importing Napa Valley soil for hillside vineyard," Aug. 27). Why do so many viticulturists plow the rows in their vineyards every year, leading to steady erosion and loss of tons per acre every year?
I've heard the claim that plowing up cover crop means less competititon for vines, but that seems specious given that most valley floor vineyards are almost too vigorous. The benefits of soil building from cover crops also seems more important, given that soil is just as important as microclimate and variety. The benefits of minimal or no tillage are also beneficial to our waterways,since sediment load can be dramatically reduced.
Some explanation here would be helpful. Based on what the Bremers are paying to truck in soil to Angwin, I'd say soil value is at least $50,000 to $100,000 per acre, at a minimum.
Editor's Note: The Register asked the Napa Valley Grapegrowers about this question and a spokeswoman said the industry is divided between those who favor tilling and those that prefer cover crops. She denied, however, that tilling automatically resulted in further erosion, saying there is some evidence that it increases the absorbancy of the ground instead.