Location: Near Ione, OR
Precipitation: 12 inches annual average
Cropping system: Flexible—winter wheat after fallow with spring wheat (dark northern and soft white), spring barley, and re-cropped winter wheat when rainfall allows.
See the companion video that introduces Bill Jepsen and describes the major benefits and challenges of flex cropping.
The area of northeastern Oregon where Bill Jepsen farms receives an average annual rainfall of 12 inches or less. To cope with these dry conditions, farmers have traditionally used a rotation of winter wheat after summer fallow. However, over the last twenty years, Jepsen has been one of a just a few farmers in the region who have experimented with intensified production.
Jepsen currently farms about 4,600 acres using a flex cropping system. When the land receives sufficient over-winter precipitation, Jepsen replaces fallow with spring wheat and barley, or occasionally re-crops winter wheat without fallow.
The flex cropping system provides a range of benefits as noted by Jepsen: “Our goal is to make the most profit, over the long haul. The flexible rotation allows us to sneak in a crop on otherwise fallow ground.”
At the same time, this strategy makes his system more resilient. Spring cropping helps control grassy weeds, while the additional residues help build soil organic matter, improve soil structure and aggregation, and increase water infiltration and water-holding capacity.
Developing Experience with Spring Crops
In the early 1990s, Jepsen started experimenting with spring crops to improve the management of fall grassy weeds. However, he soon realized that spring crops might help him more closely match the limitations of his soils (Valby silt loam and Rhea silt loam; NRCS 2013), which are rocky, permeable, and shallow (2 to 3 feet), with a solid basalt bedrock at a depth of 20 to 36 inches (Figure 1). Soil depth limits the amount of water that can be stored during the fallow year.
“Basically, from the middle of April onward, we lose all of the rain we receive during the summer and into the beginning of the fall, plus another inch out of the profile. So, with that inefficiency, why not try to take some of the water that’s going to end up evaporating, and try to grow a crop with it?”
With multiple passes required to prepare the soil for planting, Jepsen struggled in those early years to plant spring crops early enough to achieve good yields in his area. However in 1999, he had a breakthrough when he converted the farm to direct seeding in an effort to address erosion, which had been a serious issue for some time.