The Washington State University (WSU) Wilke Research and Extension Farm is a 320acre facility located on the eastern edge of Davenport, WA, and is split (north and south) by State Highway 2. WSU maintains and operates this facility. This annual technical bulletin is written for farmers and crop consultants in the intermediate cropping zone (12 to 17 inches of annual precipitation). It also provides documentation of the operations and production on the Wilke Farm to assist University faculty with small plot research experiments.
The predominant commercial cropping system practiced by farmers in this region is a 3year rotation, which includes summer fallow, winter wheat, and spring cereals. Farmers are interested in intensifying rotations to reduce fallow years and increase crop diversity to improve long-term agronomic and economic stability.
The Wilke Farm remains in a direct-seed cropping system utilizing notill fallow, and growing primarily winter wheat, spring cereals, and broadleaf crops. Broadleaf crops are used instead of spring and winter cereals when weed pressures and market prices create opportunities for profitable production.
The south side of the farm is divided into seven plots; three plots are in a more traditional 3year crop rotation, and four plots are in an intensified 4year crop rotation. The north side of the farm remains in an intensified rotation that forgoes summer fallow and is in continuous cereal grain production. In 2010 through 2013, cereal rye (feral rye) infestations caused cropping decisions to be altered on the Wilke Farm, especially in the no-till fallow-winter wheat portion of the rotations (these changes are noted in red italic in the data tables). In the fall of 2013, the notill fallow-winter wheat portion of the rotation was seeded as planned without alteration due to cereal rye because each plot had an extended rotation without fallow-winter wheat.
Soil compaction and wireworm population data are collected each spring from GPSrecorded locations within each plot. Soil samples are also collected from these GPS locations prior to seeding, and fertilizer is applied according to soil sample results and WSU recommendations.
Plot 1 and Plot 2 were lightly disked after the 2015 harvest to incorporate cereal rye seed on the soil surface, encouraging germination and improving long-term control. Winter wheat into fallow was seeded with Crop Production Services’ Case IH directseed hoe drill with Anderson openers on 12inch spacing. The spring crops were seeded with Kevin Klein’s SeedMaster hoe drill on 12inch spacing. The farm was harvested with the farm’s John Deere 6622 combine from August 4 through August 25.
Winter Wheat (3-year Plot 7; 4-year Plot 3)
Plot 3 and Plot 7 were seeded to ‘Crescent’ soft white winter club wheat on September 12-13, 2015, at 70 lb/acre into notill fallow. Seed was treated with 0.33 oz/cwt CruiserMaxx Vibrance Cereals. Liquid ammonium ThioSul, 120026, ammonium polyphosphate, 103400, and Power Up, 61861, were applied at a rate of 10-14-1-12 with the seed. In Plot 3, anhydrous ammonia was applied below the seed at 85 lb N/acre, and only 45 lb N/acre in Plot 7. Post-emergence herbicide application was applied on April 13, 2016. This application included 24.0 oz/acre Bison, 9.2 oz/acre Topsin, 3.7 oz/acre Tilt, 27 oz/acre Micro 500 fertilizer, 2.14 gal/acre CoRoN fertilizer, and 1.0 qt/100 gal nonionic surfactant. On May 25, an aerial application of 12.0 oz/acre Quilt Xcel, 0.8 oz/acre non-ionic surfactant, and 2.0 oz/acre Interlock was made for stripe rust control.
Spring Wheat (3-year Plot 2; 4-year Plot 4)
Plot 2 was seeded to ‘Glee’ hard red spring wheat into winter wheat residue on April 21 at 75 lb/acre. It was treated with 1.33 oz/cwt CruiserMaxx Vibrance Cereals. Liquid UAN-32, 1137, 9-0-0-10, and NACHURS imPulse were applied at a rate of 8-6-1-3 with the seed. Anhydrous ammonia rate was varied across three different zones to account for field variability and yield potential and averaged 82 lb N/acre. Overall 22% of the plot received 90 lb N/acre, 47% received 86 lb N/acre and 31% received only 70 lb N/acre. Three weeks prior to seeding 32.0 oz/acre Roundup RT3 and 1.5 qt/100 gal Aduro were applied. Prior to seeding an additional 16.0 oz/acre RT3 and 1.5 qt/100 gal Aduro were applied because of additional green-up due to the light disking.