I am presently reading a book titled, "The Intelligent Gardener". It discusses a methodology for analyzing more than just the macro-nutrients that mainstream agriculture focuses on, and rounding out the nutrient profile of the soil to grow healthier, more nutrient-rich vegetables. It is based on the teachings of William Albrecht (Healthy Soils, Healthy People: the Legacy of William Albrecht ).
The basic premises seem pretty straightforward. Plants, like people, benefit from an optimal mix of nutrients and micronutrients, and the people that eat them will benefit in turn.