By Paris Edwards, USDA Northwest Climate Hub and Amy Garrett, Oregon State University Extension
In parts of the maritime Pacific Northwest, climate conditions work well for dry farming, a set of soil preparation and management techniques that allow for growing food with little to no supplemental water. Dry farming has a long history of practice in the West, but a recent resurgence in popularity can be linked to water access challenges, drought, and uncertain future climate conditions. Dry farming fruits and vegetables requires a set of techniques that are evolving as the global network and local community of experts continues to expand and innovate together. So how is the reemergence of dry farming in the Northwest unfolding, and what does it have to offer growers and consumers?
Surface and groundwater resources in the Northwest are limited, subject to seasonal fluctuations, and distributed based on seniority. Increased variability in snowpack and subsequent summer streamflow and water availability adds to existing concerns and challenges. Farmers without water rights have few alternatives outside of buying, hauling and storing water on site, which comes at a cost. Dry farming is not a yield-maximizing strategy, yet it can provide an opportunity for food production on sites with deep soils and good water-holding characteristics. Practices that support dry farming include careful timing of soil preparation, early planting, cultivation or surface protection to prevent crusting and soil surface cracking, diligent weed management, soil quality improvements for water retention using organic matter additions (e.g., cover crops, compost, rotational grazing), generous plant spacing, and use of drought-resistant varieties.
The benefits of dry farming became evident in Oregon’s highly productive Willamette Valley during the 2015 drought when even the most senior water rights holders were required to stop irrigating by mid-July (Figure 1). The drought remains the worst on record for Oregon and Washington, with the lowest snowpack ever recorded across the western U.S. (Sproles et al. 2017). The resulting lack of irrigation water led to severe economic impacts to agriculture. In Washington, where drought was declared statewide by 15 May, farmers experienced an estimated $700 million in crop damages. Widely considered to represent a future climate norm, the drought turned out to be a major catalyst for dry farming ingenuity and progress for the region.
The Oregon State University Extension Service Small Farms Program is a current leader in organizing dry farming research and outreach with the Dry Farming Project. In addition to working with University researchers and local farmers to advance on-the-ground science, the group also initiated the Dry Farming Collaborative and a new non-profit, the Dry Farming Institute, to network and support farmers. The Collaborative’s peer-to-peer engagement about the art and science of dry farming has expanded as far as Europe and helped to enlist local farmers in on-farm trials. More than 50 farms, stretching from southern Oregon to northwestern Washington, recently participated in on-farm variety trials (2016–2018) that tested potatoes, corn, beans, winter squash, melon, and 200 types of tomatoes (Figure 2). Dark Star zucchini, Christmas watermelon, and Early Girl tomatoes produced some of the highest yields at participant sites and garnered top reviews from farmers. The results of the trials have informed the current generation of research (2020-2022), including:
- Work to select and develop drought-tolerant tomatoes and explore marketing and profitability;
- A corn breeding project aimed at improving hominy and masa production in the region; and
- A soil management study that tests the effects of various tillage, mulching, and fertilization treatments on tomato quality and productivity.
The pace of dry farming research is not slowing, with plans to advance farmer ability to adapt to drier conditions with locally relevant strategies.
This August and September, farmers, gardeners, students and researchers can learn in real time through a series of virtual field tours, an annual event that will be changed from the usual on-site and in-person format due to COVID-19 safety concerns. The suite of demonstrations and tours are designed to share information about crop variety performance, site suitability, management techniques, innovations in plant breeding, and address lessons learned. All are welcome, and the schedule and registration details are available on the Dry Farming Project website.
Sproles, E. A., Roth, T. R., & Nolin, A. W. (2017). Future snow? A spatial-probabilistic assessment of the extraordinarily low snowpacks of 2014 and 2015 in the Oregon Cascades. The Cryosphere, 11(1), 331.
Other useful resources:
Dry Farming in the Maritime Pacific Northwest: Intro to Dry Farming Organic Vegetables
The Dry Farming Collaborative Facebook page