TERROIR OF CANOE RIDGE, WASHINGTON – INFLUENCE OF BEDROCK AND SOIL ON GRAPEVINE VIGOR AND WINE CHARACTERISTICS

Canoe Ridge is a prominent topographic feature reflecting the Canoe Ridge anticline on the north side of the Columbia River. The ridge was first named by Lewis and Clark during their historic travels across the Pacific Northwest. Stimson-Lane Vineyards and Estates has planted about 500 acres of vinifera wine grapes on the south-facing slope of Canoe Ridge and these are divided into individual blocks ranging in size from 6-40 acres. Blocks span variations in bedrock depth and soil characteristics that formed the basis for controlled experiments to assess the influence of bedrock and soil on grapevine vigor and wine characteristics in one chardonnay and two different merlot blocks. Block 13 chardonnay is planted in N-S rows on soils that vary from a thin veneer of eolian loamy sand over bedrock to deep eolian loamy sand over glacial slackwater sediments, that overlie a N20°E ridge of vesicular basalt of the Pomona Flow of the Columbia River Basalt Group. Trenches dug up to 2m into the rooting zone identified two end member soil profiles, 1) those with carbonate-cemented basalt bedrock within as little as 20cm and 2) those with loamy sands up to 200 cm deep. Pruning weights of 36 samples in 3 replicates of vines on the shallow soil averaged 0.8 kg versus 1.3 kg for the deep soil. Means of wine pH, TA (g/L), and Brix for 3 replicate 0.5 ton batches are slightly different, 3.36, 7.4, 24.6 and 3.40, 7.1, 24.5, respectively, and qualitative sensory analysis by a 9 member panel indicated differences in sensory characteristics such as color, volatile acidity, fruitiness, and finish. The two merlot blocks were also trenched and have similar though less pronounced differences in properties such as rooting depth as in the previously described chardonnay block. Pruning weights and wine analyses for the two merlot blocks varied less but in the same manner as the chardonnay: Block 9 – shallow very cobbly soil 0.69 kg, 3.61, 5.3. 23.4; deep loamy soil 0.73 kg, 3.63, 4.8, 24.4; Block 16 – moderately deep soil over duripan 0.57 kg, 3.50, 4.9, 24.7, deep soil 0.61 kg, 3.54, 4.7, 24.9. Sensory analysis indicated the shallow-soil merlot from both blocks was better balanced and had less vegetative character than deeper soil merlot. Thus, for multiple trials for two different grape varieties there appears to be a relation between bedrock/soil and grapevine/wine characteristics.