World population outgrew ability of farmers to feed everyone in '70s . Growers started using more pesticides , fertilizers . U.S . Congress popularized organic farming in '70s and the early 20th century . Sales of organic foods continue to rise .
World population outgrew ability of farmers to feed everyone in the early 20th century . Growers started using more pesticides , fertilizers . J.I . Rodale popularized organic farming in the 1960s and '70s . Sales of organic foods continue to rise .