Adapting to a Changing Climate while Conserving Water and Growing Tastier Tomatoes

By Amy Garrett

The Dry Farming Collaborative (DFC) brings together farmers interested in pursuing alternatives to irrigated agriculture for a variety of specialty crops including: tomatoes, potatoes, winter squash, zucchini, melons, dry beans, and corn.  Growers throughout western Oregon, Washington, and northern California, increasingly affected by climate change, farm lands without water rights, or with limited water availability. Some have water rights but are interested in conserving resources (time, energy, water, etc.) and producing tastier (and sometimes longer storing) produce for their markets .

For those of you who might not know, dry farming refers to crop production during a dry season (like Willamette Valley summers), even in areas where average annual rainfall is quite high. Dry farming uses residual moisture in the soil from the rainy season, and usually occurs in regions that receive 20 inches or more of annual rainfall. Dry farming is therefore an alternative to irrigated crop production in the maritime Pacific Northwest, on sites where there is deep soil with good water holding characteristics.

Dry farmers work to conserve soil moisture during long dry periods primarily through a system of tillage, surface protection, and the use of drought-resistant crop varieties. For soil preparation and tillage, it is important to start early in the first dry window in the spring, when the soil is at about 25% available water capacity. Because we work with the moisture we have, improving soil quality and water retention with organic matter addition (e.g. cover cropping, compost, rotational grazing) is especially important.

Growers in the DFC are experimenting with surface protection or other management strategies that help conserve soil moisture for summer crop growth. This includes increased plant spacing and utilizing different kinds of mulch (e.g. wood chips and weed fabric), with ‘dirt mulch’ being the most common in the field. Maintaining ‘dirt mulch’ involves loosening the top few inches of soil after a rain event to prevent crusting and cracking, which causes the soil to dry out more quickly.

Drought-resistant and early maturing cultivars have been selected by the DFC to include in our field trials for the following crops: tomato, potato, winter squash, zucchini, melon, dry beans, and corn. Some growers in the group are also planning to make selections and save seed from crop varietals that perform well this year and move towards developing more dry farmed varieties for our region.

The DFC is not only a group of growers, but also extension educators, plant breeders, and agricultural professionals partnering to increase knowledge and awareness of dry farming management practices with a hands-on participatory approach. This bottom-up approach employs the knowledge and experience of the agricultural community in identifying adaptive strategies while simultaneously assessing and integrating them on the ground. In one year the DFC has grown to more than 200 members on the Facebook group, and 90 on the email list. Thirty growers are signed up to host dry farming trials in 2017 on a total of 12 acres, and an average of five new members join each week.

The Oregon State University (OSU) Extension Small Farms Program, where I’m an assistant professor of practice, is supporting the DFC in multiple ways:

• We facilitate communication and create space for information sharing: We manage the DFC Facebook group, email list, field days, an annual winter meeting, and we coordinate conference presentations with DFC members.
• We are building a dry farming resource hub on the OSU Small Farms website: This website will include articles, books, presentations, upcoming events, and other resources.
• We coordinate participatory research: This includes developing protocols and tools to assist with data collection, sourcing plant material for dry farm trials, and distributing those materials to growers hosting the trials.
• We develop resources to assist growers new to dry farming: We are working on a ‘Dry Farming in the maritime Pacific Northwest’ extension publication series, which discuss topics such as site assessment and selection, soil preparation and planting, case studies, and variety trial reports (expected release will begin in 2018).

The Dry Farming Collaborative is an example of how extension educators and others can design participatory climate adaptation research projects to be inclusive, broaden our reach, and have a more immediate impact. The tools and resources developed for this project could be used and modified for participatory climate adaptation research projects in our region and beyond. We hope that the DFC provides a working template to help inspire other projects in the planning phase, helping them transition into action. We can work together to co-create the future of how we manage water on our farms, knowing that the availability of water when our crops need it is likely to decrease as the climate changes. For more information visit the Dry Farming Collaborative page on Facebook or the Oregon Small Farms website.

Several Dry Farming Field Days will be held in August 2017. Dates and locations will be announced soon!