Field Day Recap
In fruit orchards across the Okanagan, growers and researchers in the BC Living Lab are testing abig question: How to grow cover crops that help mitigate climate change and support orchardproduction goals, without compromising crop health? At an October field day in Lake Country,growers and AAFC Summerland researchers braved the rain to share the successes and challengesof their collaborative research trials, and demonstrated no-till seeding in apple orchard drive-rows.
Maximize Goals, Minimize Harm
New and seasoned Okanagan fruit growers are expressing a multitude of interests in planting cover crops in drive-rows and/or crop rows. Suggested benefits for resilience range from reducing weed pressure and fertilizer use to storing more carbon in the soil, or protecting crops from sunlight reflectance. Some growers are also experimenting with mow-and-blow mulching, while others see
potential in cover crops to support biodiversity or rotational grazing. No matter the growers’ goals, project collaborators cautioned that finding the right varieties and approach takes intention, calculation of risk, and experimentation:
- Choose varieties with care; some can host pests that pose risks to orchard health: Somebroadleaf cover crop species like clovers can host undesirable pests and diseases, like theleafhopper vector and pathogen associated with little cherry disease.
- A lot can be learned from cover cropping approaches in vineyards or other tree fruits, butnot everything: As suggested for local vineyards, a legume-grass cover crop mix is a good start,but varieties quickly change with production goals. A cherry grower selected fast-decomposinglegumes for soil organic matter and lower nitrogen fertilizer needs, while an apple grower chosespecies that didn’t break down to have more control over nitrogen’s impact on fruit quality.
In-Field Insights
During a seeding demonstration, a vineyard-sized no-till seeder planted a cover crop mix tailoredto the growers’ goals for their orchard. Using a dry hopper, similar-sized seeds, and calibrating drilldepth were factors that led to successful seeding. By seeding in the fall, researchers expect moreroot than top growth, which increases soil carbon stores – a climate mitigation goal of the program.
Growing Pains, Getting Established
- Different seed sizes in a mix can require multiple planting approaches — appropriate seeding density, distribution and depth are important for crop performance.
- Equipment may not be available — a no-till seed drill with dimensions that fit an alleyway safely are costly and not yet widespread, but custom seeders from vineyards are helping.
- Integration with harvest and other production activities — the project is prioritizing varieties that can tolerate traffic, but weather variability can mean spring-seeded cover crops may still be delicate.
What’s Up Next?
The BC Living Lab’s collaborative approach emphasizes the value of trialing, observing, and adaptingpractices to fit each farm’s goals and conditions. While working with growers to trial feasibility onactive farms, researchers are continuing to assess how cover crops contribute to storing carbon inthe soil and reducing greenhouse gas emissions. Investigating drought-tolerant species, interactionsbetween temperature and moisture, and developing a cover crop selection tool are ongoing priorities.