Here's a discussion about the difference between horticulture and agriculture:
http://tobyspeople.com/anthropik/2007/0 ... index.htmlJason Godesky thinks there is a much more profound difference than merely scale.
'The distinction of “agriculture” from “permaculture” may seem quibbling or even pedantic, but it strikes directly to the heart of this phenomenon, the most important change in human history. As members of a culture on one side of that historical divide, we are naturally inclined to see our way as the only way, even though it is the novel, untested way. To call horticulture or permaculture a subspecies of agriculture is one symptom of this, a semantically Freudian slip that evinces and reinforces a much deeper cultural conviction, and a much deeper cultural narrative. By transforming the living world into nothing more than a unit of production, agriculture trains us to see all cultivation not in terms of ecological relationship, but as an economic equation of energy in and energy out. It makes our scale one of how much we modify the ecology, rather than the kind of modifications we make. Intrinsic to this view is our mythology of humans vs. nature, reflected most recently in the Romantic view of “wilderness,”9 but stretching back even further, to be found in the struggles of “human vs. nature” set up in Antigone with Antigone and Creon, and before that, in the Platonic dualism of the world of Forms, a mythic narrative of the literate mind.10 That is to say, what compels us to see horticulture as a kind of agriculture is precisely the underlying problems that define agriculture itself. Stepping beyond that gets us past clumsy phrases like Quinn’s “totalitarian agriculture,” aligns us with our colloquial understanding of the differences between “farm” and “garden,” and sets us in a point of view that immediately highlights the most fundamental crisis of our time: the catastrophic nature of agriculture, and the hope we still have in horticulture.'