Pea-canola intercropping system for intermediate rainfall zones of eastern Washington
Research collaboration opportunity to investigate pea-canola intercropping as a sustainable dryland farming practice. The system leverages biological nitrogen fixation from peas and nutrient scavenging from canola to reduce synthetic fertilizer dependence, improve yields, and enhance weed control in eastern Washington's intermediate rainfall zones.
Overview
This research collaboration opportunity focuses on developing and validating a pea-canola intercropping system tailored for intermediate rainfall zones of eastern Washington. The approach combines the complementary traits of two crop species: peas serve as biological nitrogen fixers that form symbiotic relationships with arbuscular mycorrhizal fungi, while canola contributes deeper tap roots and nutrient scavenging capabilities. Together, these crops can improve nutrient cycling, reduce dependence on synthetic nitrogen fertilizer, and increase overall farm profitability. The system also offers secondary benefits such as enhanced weed control through allelopathic pest repellence and improved land use efficiency.
Technical specifications
Research approach:
- A randomized complete block design with split plot will be established at the Wilke Research Farm near Davenport, WA
- Treatments include five intercropping configurations: canola alone, one-third pea plus two-thirds canola, one-half pea plus one-half canola, two-thirds pea plus one-third canola, and pea alone
- Nitrogen rate treatments include zero pounds per acre, 50 percent of canola nitrogen requirement, and 100 percent of canola nitrogen requirement
- Soil samples will be analyzed for nutrient content, moisture, arbuscular mycorrhizal fungi populations, microbial biomass and respiration, organic matter, particulate organic matter, and mineral-associated organic matter
- Yield data will be collected and Land Equivalency Ratio calculated to evaluate system efficiency
Technology readiness level
This is an early-stage field research initiative. A new field trial is planned for establishment in April 2024. The research builds on prior studies across Canada, Australia, and the United States that demonstrated yield benefits from legume-oilseed intercropping systems, but adapts the approach specifically to the dryland intermediate rainfall conditions of eastern Washington where validated data has been lacking.
About Washington State University
Washington State University is a comprehensive public land‑grant research university serving the state through a multi‑campus system anchored in Pullman. Industry engagement runs through a research and technology park in Pullman, a health sciences campus in Spokane integrated with regional hospitals, and a statewide extension network linking faculty with companies and communities. The Tri‑Cities campus sits minutes from a U.S. Department of Energy national lab, enabling collaborations, shared facilities access, and talent pipelines for regulated sectors. Research is supported by competitive federal funding from agencies such as NSF, NIH, USDA, DOE, and DoD. A dedicated technology transfer office manages IP, licensing, and startup support, complemented by incubator and pilot‑scale resources.
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