What is a typical base saturation?

What is a typical range for base saturation in soils? What base saturation percentage is high enough to predict an above average pH?

We did not discuss this in our course, since (as every other topic mentioned in this Introduction to Soil Science course) there is so much more behind the concepts covered. There is some disagreement among soil scientists about the value of using "optimum" or typical base saturation ranges. One school of thought holds that it is very important that the soil contain a specific base saturation, or ratio of saturations for each of the major cation nutrients (Ca, Mg, K). Practitioners of this approach will make recommendations designed to adjust the soil to specific saturation levels. The opposing view is that there can be a wide range of saturation for each of these major cations, with no significant benefit to having particular saturation levels or ratio of saturation levels. The evidence suggests that the primary need is for an adequate amount of each nutrient, regardless of the resulting percent saturation, and that the desired saturation range can be quite broad. To the degree that there is an "ideal" percent saturation range or ratio of cation nutrients, it would be affected by several other factors such as plant species, the intended use of the plants, the nature of the soil itself, etc.