I have read it and others like it (the intelligent gardener is the spin-off of it) and have tried to implement it years ago and I never got the soil balancing concept to work or provide any economic benefit. I think most gardeners mostly don’t do anything other than compost so his point about high compost imbalancing soil is correct and anytime in that environment you add minerals you will get a response (or don’t add the ones already high). But in commercial ag, I think this book is a no-go. I have had much better success implementing a regenerative and biological approach to the soil, and using plant sap analysis and foliar feeding of high quality chelated nutrients.