[Repost from 2012]
David Little of Little Organic Farm has had to adapt to water scarcity in Marin and Sonoma Counties, where most farmers and ranchers rely on their own reservoirs, wells, and springs, making them particularly vulnerable in years with light rainfall. Through a technique known as dry farming, Little’s potatoes and squash receive no irrigation, getting all of their water from the soil.
Mediterranean grape and olive growers have dry-farmed for thousands of years. The practice was common on the California coast from the 1800s through the early 20th century, but it became a lost art during the mid-century. Today, it is experiencing a modest resurgence along the coast, where temperate, foggy summers offer ideal conditions for dry farming grapes, tomatoes, potatoes, cucumbers, melons, grains, and some tree fruit
“In the beginning, I searched out people who were known dry-farmers,” says Little, who started in farming in 1995. “It seemed like no one had done it for 30 years or so, and then it wasn’t done much.”
To find mentors, Little made the rounds at local bars, asking older farmers about their experiences. “They were very humble,” he says. “They told stories about how things were done, and I would pick up tidbits.” After years of trial and error, he now considers himself an expert.
To help people understand how dry farming works, Little often evokes the image of a wet sponge covered with cellophane. Following winter and spring rains, soil is cultivated to break it up and create a moist “sponge,” then the top layer is compacted using a roller to form a dry crust (the “cellophane”). This three- to four-inch layer, sometimes referred to as a dust mulch, seals in water and prevents evaporation.
“It’s very challenging because you have to hold the moisture for long periods of time, and you don’t know how different crops are going to react in different areas,” Little says. Much of the land he farms is rolling hills and valleys, which present additional challenges because they hold and move groundwater differently than flat land.
Deprived of any surface irrigation besides the coastal fog, dry-farmed plants develop deep, robust roots to seek out and soak up soil moisture. Because they absorb less water than their conventionally irrigated counterparts, dry-farmed crops are characteristically smaller but more nutrient-dense and flavorful.
“When you water a tree, it dilutes the flavor a lot in some cases,” says Stan Devoto, who dry-farms more than 50 varieties of heirloom apples at Devoto Gardens. “Instead of having a really hard, crisp, firm texture, your apple will be two or three times the size of a dry-farmed apple, and you just don’t get the flavor.”