KPU study explores dry farming potential

COMOX VALLEY – Research on dry farming practices in the Comox Valley is helping an international study foster more resilient production systems.

“We need a very large set of tools to adapt to climate change. We know it’s not going anywhere, and we know that droughts are going to become increasingly a source of stress on farmers, both from a production standpoint and from a mental health standpoint,” says Naomi Robert, senior research and extension associate at KPU’s Institute for Sustainable Food Systems, who is leading the research. “Dry farming is one of those tools.”

Based in the Comox Valley, Robert and her team partnered with the Dry Farming Collaborative at Oregon State University to learn how to apply dry farming practices locally in response to the severe drought that hit the Pacific Northwest in 2023.

The objective of dry farming is to retain soil moisture for as long as possible by investing in soil health, using drought-tolerant species, spacing plants appropriately and mulching to prevent evaporation and weed emergence. It is best practiced in areas that have a cool wet season followed by a warm dry season.

Robert worked with three market gardeners last year to determine dry farming approaches that are appropriate for Vancouver and Gulf islands soils: Skye Larmour of Salt Spring Island’s Golden Maple Farm, Jaclyn Kirby of Yellow Boot Farm in Black Creek and FarmFolk CityFolk’s Lisa Willott at the Sandown Centre for Regenerative Agriculture in North Saanich.

Dry farming is nuanced, depending on the farm site and resources available. Some of the best sites are those with soils able to hold moisture; sandy and stony soils are less suitable.

For some growers, dry farming may mean no irrigation for the entire growing season. For others, it may mean strategic or reduced irrigation use.

The common thread for all three producers participating in the study is a desire for practical, full-farm approaches to drought management.

The well at Golden Maple Farm never ran dry when Larmour was growing up, but the occurrence has become commonplace in recent seasons.

When temperatures soared above 40°C during the 2021 heat dome, she realized the farm needed to adapt to a new reality.

“I thought a lot about how do we adjust to this situation, and I came to believe that a forward-looking perspective would be to learn how to grow within water constraints,” she says. “I began the journey of researching dry farming and irrigation, and the biology of plant water use and techniques to stretch water further.”

In 2024, Larmour also launched Tardigrade Seeds to provide climate-adapted crops and help growers find new varieties that perform in a changing climate.

Larmour’s research led her to KPU’s dry farming trial. She was eager to take part, knowing the support of others would be critical to the strategic integration of dry farming practices on her farm.

On-farm trials for Robert’s study began last May. Participating growers each planted the same tomato, winter squash, zucchini and dry bean varieties as part of a replicated trial. Each site had a weather station and eight soil moisture sensors to collect data at one, two, three and four feet deep.

“We can see how soil moisture changes throughout the season,” Robert says. “The top part of your soil dries out almost completely by a certain date depending on the site, usually sometime in July. But by then, the crop’s [roots] are deep enough so that they can access the moisture at depth.”

Kirby shares a well with the landowners at Yellow Boot Farm, so irrigation is not a viable option.

“Dry farming just makes sense in our area,” Kirby says.

For the little water she needs, Kirby credits the landowners for installing a rainwater capture system. But without irrigation, succession plantings are not feasible in dry-farmed systems.

“It does lower … the amount of crop that we actually harvest, but it also lowers our labour,” Kirby says.

One of the most interesting findings was that tomatoes and zucchini thrived without irrigation.

“The tomatoes did way better than I thought they would,” says Willott of her experience in North Saanich. “Zucchinis are quite wet; [they] have a lot of water in them, and they did great.”

Throughout the season, regular weeding was crucial to preserve crop-available water.

Willott laid down paper mulch, Larmour invested in landscape fabric and Kirby hand-weeded each week to keep the weeds at bay.

One year of data raised questions around fertility, variety selection and developing place-based guidelines for dry farming on the West Coast.

Side-dressing dry-farmed crops with granulated organic fertilizer could mean the nutrients aren’t accessible once surface moisture is depleted. Growers would like to know if a liquid foliar application would work instead.

Robert hopes to continue replicated trials this year to dive deeper into some of these research questions.

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