Water Resilient Strategies
Our climate is changing.
We may think of Bellingham as cold and rainy, but our city only gets about 39” of precipitation a year! That’s less than Orlando, Boston, and New York City. As summers grow longer, hotter, and drier, we need to investigate ways of conserving water in food production. The Outback is honored to work with the American Farmland Trust and the Dry Farming Institute during the 2024 season to experiment with water-saving practices.
Mulching: covering the ground
(L) straw mulch around sugar snap peas; (R) plastic weedcloth mulch around strawberries
Mulch is a protective layer of a material spread on top of the soil. We’re experimenting with plastic weed cover, straw, and dust mulch to:
- Keep the soil cool
- Capture water and help it soak into the soil
- Slow water evaporation from the soil by up to 35 percent
- Cut back on weeds by blocking sunlight they need to grow
There are costs and benefits to each system. Plastic covering can be durable for many years, which is cost effective and cuts down on labor. But the material does slowly degrade and can leave microplastics in the soil. Straw is easy to obtain in small amounts and is cost effective for the home gardener, but can be cumbersome and expensive for larger areas.
Timing is important when it comes to mulching – if the soil is covered too early, we create happy habitats for snails and slugs that love to eat baby plants. It’s best to lay mulch down when the weather turns hot and dry, often not until late June or July in Bellingham.
Moisture Sensors: data-driven irrigation decisions
Thanks to our generous sponsors, we installed moisture sensors at 1’ and 3’ to track moisture in the soil. Our farm staff takes readings of the sensors five times a week to track how much water is available to the roots of crops. We use the data to understand when the plants truly need watering – and it’s been surprising how infrequently we’ve had to irrigate so far this season! There are multiple benefits to this process:
- Reduces our water use
- Cuts down on staff time spent watering
- Clear communication between team members on watering decisions
- Ability to be responsive to plant water needs on a daily basis
- Improves our understanding of our soils (for example, at 3’ our very clay-heavy soils are still saturated in late July from spring rains)
Moisture sensors are installed in two different growing sites in the Outback. This allows us to compare the two sites on the farm with different soils and sun exposure. We already discovered that our south field dries out more quickly, possibly due to lower organic matter content in the soil.
(L) installed moisture sensor and current reading; (M) tools for installing sensors; (R) Outback farmer Skye Schultz installing moisture sensors.
Drip Irrigation: smart watering systems
Photo shows a drip line watering a cucumber plant, from www.dripworks.com/drip-irrigation
Drip irrigation, rather than watering by hand or with a sprinkler, can save up to 70% on water bills by applying water directly to plant roots. It reduces evaporation and wind loss during the watering process. The drip lines only water right where it’s needed, and not onto paths, aisles, or unplanted areas. Drip systems also distribute water slowly, so the water has a better chance of sinking into the soil, which cuts down on runoff and water waste. All this combined means we don’t need as much water to care for our crops.
Drip irrigation can promote deeper root growth and disease resistance. It also minimizes water contact with leaves, stems, and fruit, which can help prevent disease. The only drawback is the initial cost to purchase pressure monitors, drip lines and tape, connectors, etc. and the labor to install the system.
Planting perennials: designing sustainability
We’re used to thinking of farms as places with long rows of identical crops that are planted and harvested in one season. But in our PNW forest-based ecosystem, there are positive impacts to growing perennial plants for food and fiber. In the Outback food forest, we have fruit and nut trees, berry bushes, grape vines, hardy herbs, and native plant species. Switching from annual vegetables (that need to be planted and irrigated every year) to perennials like trees and shrubs has many benefits:
- Once established, trees usually don’t need to be irrigated, which conserves water
- Creates shade and keeps the soil cool, which cuts down on evaporation
- Allows rain to trickle down slowly to the ground, helping it absorb slowly into the soil
- Honors Indigenous wisdom and culturally significant traditional foods of the Lummi and Nooksack peoples
- Forms habitat for wildlife, pollinators, and beneficial insects
- Requires pruning and composting, but otherwise quite minimal work compared to garden vegetables
- Yields some of our favorite foods ranging from hazelnuts to nettles to pears to honeyberries
Apples on a tree in the Outback Forest Garden.
Many thanks to our wonderful partners:
The USDA National Institute of Food and Agriculture
We’re proud to use seeds from Uprising Seeds for local varieties and Adaptive Seeds for drought-resistant varieties