Washington State University researchers announced that nearly two decades of trials at the Wilke Research and Extension Farm show growers can benefit from reducing summer fallow and growing broadleaf crops more frequently.
That finding challenges farming practices common in eastern Washington for nearly 100 years. A typical three-year rotation in the region leaves fields unplanted for an entire year to conserve moisture, followed by winter wheat and a spring cereal like barley or wheat.
“I feel very confident telling growers they can take a chance on extending their crop rotations by reducing summer fallow and incorporating more broadleaf crops,” said Aaron Esser, regional Extension agronomist at WSU and manager of the Wilke Farm, according to news.wsu.edu. “Our research shows that this kind of crop intensification can be economically beneficial over time.”
Crop rotations reduce erosion
Continuous crop rotations offer advantages beyond increased profitability over time, according to research published by the university’s Office of Research. Stretching out growing rotations reduces erosion potential because roots remain actively growing in the soil.
“It means more active and beneficial soil biology,” Esser said, as reported by news.wsu.edu. Esser publishes an annual report detailing the Davenport-based farm’s performance so local producers can evaluate the results against their own fields.
“This is a very specific dataset from Wilke Farm that applies to dryland wheat cropping in eastern Washington that you can’t replicate anywhere else,” Esser said, according to news.cahnrs.wsu.edu. “That’s why grower support is tremendous for the work we’re doing.”
Market decisions depend on rainfall
Management decisions at the 13-inch annual rainfall site depend heavily on shifting markets and local weather patterns. Because rainfall totals vary widely across the region, continuous cropping is not universally applicable.
“Because rainfall totals vary widely from Lind to Pullman, that means that some farmers will be able to grow chickpeas or canola in their rotations, and others won’t,” Esser said, as noted by news.wsu.edu. Microclimates also dictate whether continuous cropping can succeed on a given acreage.
“If the price of barley was up high enough, we would be incorporating barley,” Esser said, according to research.wsu.edu. “I try to make these decisions much like a farmer would have to make decisions on their farm.”
Farm runs soil health trials
Beyond dryland wheat and crop rotations, Wilke Farm runs trials examining long-term soil health, cover cropping, and herbicide-resistant weeds. Vicki McCracken, director of WSU Extension, said the facility highlights the land-grant mission.
“One of the things I value about Extension is working alongside producers on the questions that matter to them,” McCracken said, according to news.cahnrs.wsu.edu. “Wilke Farm gives us a place to explore those questions together and put what we learn to work for eastern Washington growers.”
Raj Khosla, dean of the College of Agricultural, Human, and Natural Resource Sciences, added that two decades of sustained investment provide accessible data for agricultural decision-making. “This research helps make agriculture in eastern Washington more adaptable and resilient in the face of pressing challenges,” Khosla said, as reported by research.wsu.edu.
Eastern Washington Crop Questions
How much annual rainfall does Wilke Farm receive?
The research facility receives about 13 inches of rain annually, placing it within the region’s intermediate rainfall zone.
What traditional practice do researchers suggest reducing?
The team suggests reducing summer fallow, which leaves fields unplanted for a year to conserve moisture.
What specific crops might farmers add to rotations?
Depending on local rainfall and market prices, growers may incorporate broadleaf crops like chickpeas or canola, or spring cereals such as barley.
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