Before trellis installation each block of the vineyard was surveyed with centimeter resolution GPS. Multiple soil samples were then taken in each block at GPS surveyed locations. The soils are all classified as sandy loams or sandy silt loams, predominately of the Scoon series. The Scoon series consists of very shallow, well-drained soils on terraces and alluvial fans. This is typical of a geological location where a wind-blown loess has been deposited on a more durable substrate. The underlying sediments, glacial outwash, were deposited 13,000 to 20,000 years ago by catastrophic floods of glacial melt water from Glacial Lake Missoula. The flood water reached an elevation of 1450 feet.
Soil Depth in North 80% of Stone Tree Vineyard
In the vineyard, the soil is distributed in a 1 – 3 foot layer over an underlying hardpan “caliche”. This is a water-impermeable, limestone/rock aggregate. These layers can be seen in this photo taken during the installation of our irrigation system. The soil varies from moderately rocky at the bottom of the slope, to very rocky at the top of the slope. This rocky soil with a calcium carbonate/rock aggregate base is similar to the soils of the great vineyards of Bordeaux.
Soil Profile in Irrigation Ditch
During site preparation, the soil was ripped three times to a 3 foot depth in 3 different directions with a D-8 Cat. Two of the ripping passes were diagonal, that is northwest-to-southeast and northeast-to-southwest. The final pass was east-west. We did not rip north-south so as to avoid irrigation water channeling along the rows.