Farmer in Chief by Michael Pollan

"But if taking the animals off farms made a certain kind of economic sense, it made no ecological sense whatever: their waste, formerly regarded as a precious source of fertility on the farm, became a pollutant — factory farms are now one of America’s biggest sources of pollution. As Wendell Berry has tartly observed, to take animals off farms and put them on feedlots is to take an elegant solution — animals replenishing the fertility that crops deplete — and neatly divide it into two problems: a fertility problem on the farm and a pollution problem on the feedlot. The former problem is remedied with fossil-fuel fertilizer; the latter is remedied not at all."

All, from NYT