Farmer David Little of Little Organic Farm grows potatoes without irrigation in a dry part of California.

This week, as the nation grapples with the worst drought in decades, the USDA added more than 218 counties to its list of natural disaster areas, bringing the total to 1,584 — more than half of all U.S. counties. Farmers in the Midwest and Great Plains have been the hardest hit, but the drought is a growing reality for farmers across the country, including California. While the secretary of agriculture won’t comment on the drought’s link to climate change, it’s at the forefront of everyone’s mind, and as global warming unfolds, knowledge of dryland agriculture will become increasingly valuable.

David Little of Little Organic Farm has had to adapt to water scarcity in California’s 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.