Author: Amy Garrett, Small Farms Program, Oregon State University
Publish Date: Summer 2013
Jeannie Berg, with Your Hometown Harvests, grows heirloom fruits and vegetables in Monmouth, Oregon. She markets her produce through a 25-member CSA and several farmers’ markets including the Independence Riverview Market and the Portland South waterfront market. The land she is farming has class 1 soil and a few acres of water rights, but not enough water to expand irrigated crop production, so Jeannie has been experimenting with dry farming vegetables over the past few years.
What is dry farming?
Dry farming refers to crop production during a dry season, like our summers here in the Willamette Valley, and utilizing the residual moisture in the soil from the rainy season instead of depending on irrigation. Dry farming strategies work to conserve soil moisture during these long dry periods through a combination of management strategies including drought-resistant varieties, the timing of planting, tillage, surface protection, and keyline design. Regional rainfall, type of crop, planting depth and spacing, and soil type are important considerations. For example, soil quality and water-holding capacity is especially important for dry farming systems and wouldn’t be feasible for most crops on a really well-drained sandy soil with little to no organic matter. For each 1% increase in soil organic matter, soil water storage can increase by 16,000 gallons per acre-foot of applied water (Sullivan, 2002)! Many people think of grains and beans when dry farming is mentioned, however, farmers in the western region of the U.S. have dry-farmed many other crops including grapes, garlic, tomatoes, pumpkins, watermelons, cantaloupes, winter squash, potatoes, hay, olives, and orchard crops (http://www.agwaterstewards.org/).
The strategy for managing soil moisture at Your Hometown Harvests, involves deep straw mulch, low/ no irrigation, and low/no-tillage. After two years of trialing this system and great success with tomatoes and winter squash, she has decided to expand dry farming onto two more acres.
Mulch Day at Your Hometown Harvests
In preparation for this expansion, Jeannie organized a farm mulch day on April 27th this spring, inviting people out to tour the farm, help spread 450 bales of straw, and learn how to reduce weeds and conserve water on their own land with this technique. Twenty people attended and were able to mulch over a half-acre that was then planted mostly in tomatoes, as well as some squash and local heirloom ‘Pike’ melons. She also put a few of each variety she planted in a “control plot” up near her house that will get irrigated for comparing yield, taste, and vigor.
Why dry farm?
When asked what her primary motivating factors for dry farming are Jeannie replied, “to build soil, conserve water, and hopefully get consistently more flavorful and nutritionally dense tomatoes.” She attended the annual North Willamette Horticulture Society meeting held each January (http://nwhortsoc.com/) and saw a presentation on ‘Genetic and Environmental Factors Influencing Vegetable Flavor and Human Health Potential’, by Ted Radovich with the University of Hawaii. The presentation affirmed her hope that more flavorful and potentially more nutritionally dense tomatoes can result from some water stress.
Jeannie said, “In four years of farming without chemicals, we’ve become convinced that organics is only a part of the picture and that we have to address the extent that we use water and damage soil structure with tilling.” Reasons for dry farming may range from necessity in the case of no water rights or a drought to interest in soil conservation or better-tasting tomatoes. If you are interested in exploring dry farming further see the resources below.
Resources
California Agricultural Water Stewardship Initiative:
http://agwaterstewards.org/
Ecofarm Water Stewardship Project:
http://agwater.wordpress.com/
Sullivan, P. 2002. Drought Resistant Soil. ATTRA Agronomy Technical Note. p. 1-7.