Computer-controlled center-pivot irrigation, No-till farming cuts

City farming—Pigs in the Sky?

By Dennis Avery Monday, October 18, 2010

CHURCHVILLE, VA—Green visionary, Dixon Despommier, of Columbia University has proposed growing our food in city high-rises, to cut food transport energy use. The bad news is that city farming would be impossibly expensive—as it always has been. The good news: the high-rise farms will never be built.

Another project, the Sky-farm Project was proposed in 2007, as a 58-floor skyscraper that would produce as much food as an 800-acre farm! But the U.S. farms more than 400 million acres of land—equal to 500,000 skyscraper farms! Those sky-towers would cost billions.

Cropland in Iowa costs an average of $6,000 per acre or about $5 million for an 800 acre farm. An acre or so of usable land In Manhattan might cost about the same $5 million, but construction costs would be enormous.

Each floor of each high-rise would have to support either water-soaked soil or the water for hydroponic production. Ten thousand cubic feet of water per floor would weigh 620,000 pounds. Two hundred people plus their office furniture might weigh only 40,000 pounds.

Replacing sunlight with “grow lightsâ€