TERROIR DIFFERENTIATION OF PINOT NOIR VINEYARDS IN THE NORTHERN WILLAMETTE VALLEY, OREGON - A SOIL ANALYSIS

Pinot Noir wine is an important commodity in Oregon, with more than 300 wineries in the Willamette Valley producing over 5.6 million cases. An important topic among winemakers and drinkers in the region is how the different soil types affect the flavors of the wine produced on them. There are three prominent soil types used for growing Pinot Noir in the Northern Willamette Valley. These are the Jory (Xeric Palehumults), Willakenzie (Ultic Haploxeralfs) and Laurelwood (Ultic Haploxeralfs) Series soils. These soils, and others, have distinct bedrock parent material, depths, textures, clay mineralogy, and chemistry. Parental material is either basalt, basalt with loess accumulation or sandstone and shale. Soil pits were dug in 20 different vineyards owned by six separate wineries over the course of two summers. Each winery owns vineyards or sources from vineyards on the various soil types, allowing for the winemakers to use the soil variation to create wines of different flavors. Grain size analysis, pH, clay mineralogy, and trace element analysis using Inductively Couple Plasma – Optical Emission Spectrometry (ICP-OES) will be completed on each soil horizon. To assess the affect of the soil trace element composition on wine, grape must from the clusters grown on vines immediately adjacent to the soil pits and the resulting wine from the vineyard block will also be analyzed using ICP-OES. Preliminary results reveal the Jory soils are around 1.5 meters deep with silt loam and clay loam texture on basalt bedrock. The Willakenzie soils are form on sandstone bedrock at 2 meters depth and have clay loam or sandy clay loam texture. Laurelwood soils are the result of basalt bedrock covered by a layer of loess. The resulting soil has many concretions that form in the A horizon and silt loam or clay loam texture with depth. As an ongoing project, results hope to provide a trace element fingerprint for the vineyard soils in the Willamette Valley and assess the contribution from the wine making techniques on the trace element composition of the wine.