Central Oregon is a vibrant agricultural region with 60,000 acres of irrigated croplands. Jefferson County features specialty seed production while fresh market vegetable farms are emerging in Crook and Deschutes counties. These high-value, irrigated, annual cropping systems are intensively managed and require excellent soil quality in order to be successful on both the small- and large-scale operations.
Cover crops are grown in rotation with main crops to improve soil health and crop success. While cover cropping is used across Oregon, there is limited information about growing them in central Oregon. New research results from the Oregon State University Extension Service are helping central Oregon farmers make timely decisions on which cover crops to use and when in their annual planting cycles.
At the request of local small-scale organic growers, Clare Sullivan, assistant professor of horticulture and OSU Extension small farms and specialty crops agent, spent a year researching optimum species, varieties and planting dates for cover crops in central Oregon. The trial was conducted at the Central Oregon Research and Extension Center in Madras, where Sullivan is an associated faculty member.
Cover crop varieties were planted in spring, summer and fall and observed for several characteristics.
The year-long project found that some species did better when planted in spring vs. the summer, some were better at weed suppression, and some created more biomass. Some species planted in fall survived the winter and flourished in the spring.
Also, the fall-planted cover crop trial was only irrigated twice from planting to termination, a practice that revealed cover crop success with low water use. In an area where irrigation water is limited, water use of cover crops is a concern for farmers.
In addition to small-scale growers, the research attracted the interest of larger-scale conventional growers in Jefferson, Crook and Deschutes counties.