Here is an excerpt from p. 60 to lure you in:
The problem of nutrient depletion starts at the beginning of the food chain. Plants are grown in soils that are depleted of minerals. Mass production of food leads to abuse of the land, and fertilizers do not deliver their promise. Vital foods, such as vegetables and fruits, are rendered nutritionally inert, because they are deficient in trace minerals that used to be abundant in rich, healthy soils. (Soil degradation is one of Earth's silent crises - it is only now beginning to get attention, but it is slowly harming the whole planet's food-cultivating ability.) The Vitamin A in tomatoes has gone down 43 percent in the last six decades; the Vitamin C in potatoes has decreased 57 percent. Unless you bought your vegetables and fruits at a farmers' market, they have most likely been harvested long before ripeness (depleting them of essential nutrients your cells need to do their chemistry), and unless you know otherwise, your produce almost definitely came from nutrient-depleted soils.
Does that scare anyone else? That's only one of many reasons why I want to grow my own food according to the biointensive method I wrote a tiny little bit about here.