I read this article on urban farming this weekend, and thought "heartwarming, but uselss." So far it's required subsidies of $1 million to produce a small amount of food--the Times glowingly says that it "provide(s) healthful food to 10,000 urbanites", but of course, all that means is that 10,000 people, give or take, have received at least one vegetable apiece. It's not providing anything like the majority of their food intake. And that's in a rust-belt city with a lot of spare land and spare labor.
Ezra argues that industrial agriculture gets subsidies too, and this is true--but not the things these people eat. More to the point, the subsidies are not why American agriculture has so many vile practices. What enthusiasm for these sorts of projects fail to deal with is scale.
Scale matters in two ways. First of all, scale is why so many promising pilot projects fail to yield results when they're implemented broadly--think how many terrific new education and medical programs you've read about over the years, which delivered mediocre results when they became more popular. Pilot projects have a deep pool of enthusiastic and skilled labor. There is the excitement of the new, of possible discovery, driving everything forward. Broad programs are applied by ordinary busy people with no stake in revolution. Over time, the enthusiasm wanes. Urban gardening is not new, after all--it was in vogue during the Settlement House movment, the 1940s, and again in the hippie sunset of my childhood, when I, along with the other children of PS 166, dutifully weeded little herb patches on 89th and Amsterdam. By the early 1990s, many of those lots had been abandoned or turned into condos.