If you are interested in learning more about J. Russell Smith, the author of "Tree Crops", I recommend this article (where I pulled the quote from) which just happened to drop yesterday.
https://daily.jstor.org/he-spoke-for-the-trees-and-also-the-soil/
Economic Botany
"I here call attention to the idea of a new agriculture, a tree-crop agriculture, which seems to hold the promise of easily doubling our productive area and making revolutions in man's relation to his environment second only, perhaps, to the influence of steam." - J. R. Smith
The Oak Tree and Man's Environment
J. Russell Smith
