Investigating Seeding Rate of Cover Crops for Biomass and Nutrient Content

By Mary Hathaway and Anthony Reyes

Oxbow Farm & Conservation Center is a nonprofit farm in the floodplains of Snoqualmie Valley, WA. Anthony Reyes, the Agricultural Program Manager, manages 81 acres of certified organic land by experimenting and trialing climate adaptive and resilient agricultural practices. Along with his team, he works to reconcile our expanding human needs and the health of our ecosystem through sustainable agriculture, thoughtful management of our forests, ecological restoration, and education.

Oxbow Farm cultivates a variety of different crops well suited to the Snoqualmie Valley floodplain, and maintains a crop rotation to allow the soil to recover and regenerate. Anthony strategically removes fields from production each year and leaves them fallowed in cover crop to help protect the watershed, build up nutrients, and manage weeds, pests, and diseases.

Finding a Cover Crop that Works

Anthony was interested in understanding how to find a cover crop that would meet the needs of the farm – managing climatic challenges, erosion, and weed pressure. Ideally, anything that would be planted would help add biomass and could withstand drought conditions. Manipulating the seeding rate of the cover crops had been one way that the farm had considered better coverage of the soil, and Anthony was curious if the recommended seeding rate was the right density for their soil.