Jory Soil Series

Jory soil has low natural fertility — and that is exactly what Willamette Valley winemakers want. Low nutrients force grapevines to produce smaller, more concentrated berries, which is why Pinot Noir grown on Jory hillsides earns some of the highest prices of any American wine.

The soil formed from weathered Columbia River Basalt — ancient lava flows that buried the Willamette Valley millions of years ago. As the basalt broke down over hundreds of thousands of years, iron in the rock oxidized and turned the soil its signature dark red. Jory is one of the reddest soils in the Pacific Northwest.

Oregon's Legislature designated the Jory series as the state soil in 2011, after a campaign led by the Soil Science Society of America and supported by the Oregon Department of Agriculture and the USDA Natural Resources Conservation Service.

The series is named after Jory Hill, a prominent basaltic knob in Marion County in the northern Willamette Valley, where soil scientists first formally described and mapped the series. The type location remains in Marion County today.

Jory was chosen to represent Oregon because it defines the Willamette Valley landscape more than any other soil — the red hillsides, the vineyards, the hazelnut orchards, and the grass seed fields that cover the hills between the Coast Range and the Cascades.

Dig into Jory soil and the color is unmistakable: the surface is very dark reddish brown, almost burgundy. A few inches down it darkens further before brightening into a vivid red in the argillic subsoil. The deeper you go, the redder and stickier the soil becomes — clay content increases steadily until you are deep into dense, iron-rich red clay. At depth, this grades into partially weathered basalt.

Jory soil grows on the basalt-capped hills and ridges at the margins of the Willamette Valley — the elevated terrain between the valley floor and the Coast Range and Cascade foothills. It sits at elevations of 200 to 1,800 feet, on slopes of 2 to 60 percent, where annual rainfall ranges from 40 to 60 inches.

The soil is concentrated in Yamhill, Polk, and Marion counties in the northern Willamette Valley — the heart of Oregon's wine country. It also appears in Washington, Benton, and Linn counties to the south.

Pinot Noir is the crop most closely associated with Jory soil. Willamette Valley winemakers discovered that the soil's excellent drainage, low nutrient levels, and red iron chemistry produce grapes with the thin skins, high acidity, and concentrated flavor that define world-class Pinot Noir. Oregon's Pinot Noir industry is built largely on Jory hillsides.

Hazelnuts are the second signature crop. Oregon grows 99 percent of the commercial hazelnuts in the United States, and Jory soil's well-drained hillsides in the Willamette Valley are where most orchards grow. Hazelnut trees thrive in the rocky, low-fertility conditions that Jory soil provides.

Grass seed, winter wheat, and Christmas trees grow on flatter Jory sites. Douglas fir and Oregon white oak are the native trees found on Jory-covered hillsides that were never cleared for agriculture.