Ungrazed natural range pasture soils: Knights Valley, Sonoma County. Well established Bunch grasses with deep roots. Much organic matter on and near the Suther Loam soil surface.

Although organic matter is important in soil, viticulturists usually do not think much about it. They are too busy managing their crops and vines, controlling pests and diseases, irrigating, organizing labor and doing other things. Plus, many viticulturists think that supplying organic matter to soil is too costly.