What's your impression of that book? Asking because interested in that area, have done some on it (organic gardening in general, though not the intensive kind like in that book), and have read a similar book by John Jeavons:
Excerpt from this page on his site:
http://www.johnjeavons.info/john-jeavons.html
[ A political science graduate of Yale University, Jeavons worked for the United States Agency for International Development (USAID) and Stanford University before launching his career in small-scale agriculture education. He is the author of the best-selling sustainable farming handbook How to Grow More Vegetables, Fruits, Nuts, Berries, Grains, and Other Crops Than You Ever Thought Possible On Less Land Than You Can Imagine, now in its 8th edition in eight languages ]