2Tree Crops: A Permanent Agriculture, first published in 1929 and last updated in 1953 (and the edition reprinted here) is a classic, pioneering look at the use of trees for food, soil conservation, and sustainable agriculture. Author J. Russell Smith (1874-1966) travelled widely and shares his insights and research into agro-forestry, describing how trees such as carob, honey locust, persimmon, mulberry, oaks and pecans can be used to enrich the land and the people and animals dependent on it. Illustrated with over 80 pages of photographs.