Included in mapping are some areas that are not so severely eroded. Other included soils have a surface layer less than 16 inches thick. Also included are soils that have slopes of less than 9 percent. Some areas of Pleasanton soil are also included. Permeability is very slow.
Surface runoff is medium, and the erosion hazard is moderate.
Fertility is low. The photograph above shows a nice cross-section of ripped Tierra Sandy Loam from the hillside Pinot Noir planting. This is the soil profile that made us excited about growing Pinot Noir here at Clos Pepe. Many local winemakers look for high calcium content in soils for Pinot Noir, because of the anecdotal belief that it imparts a mineral complexity to the wine. Note the rich brown color of the clay, and the flecks of shale, stone and red clay.