National Geographic : 1970 Dec
"My grandfather was an Illinois prairie farmer," he said. "Granddad rotated his crops; every few years he'd grow alfalfa or red clover and plow it under to replace the humus and nitrogen in the soil. He used lime, but I doubt if he ever bought any artificial fertilizer. After harvesting a crop, he'd turn his animals into the field, and they'd fertilize it. "Things are different now. Land out there is so valuable that farmers feel they can't afford to do anything except grow corn on it every year, using chemical fertilizers to boost the yield. But unfortunately those chemicals tend to leach out and add to our problems in rivers and lakes." I asked Dr. Cole if manure was obsolete. He smiled. "Nowadays, it's more of a prob lem than it is a fertilizer. You don't turn cattle out into the field any more. You herd them into feed lots, and bring the feed to them. You wind up with a manure disposal problem in the feed lot and a shortage of organic fertilizer in the fields." * What should be done? Dr. Cole shrugged. 768 "It seems to me that it would make a lot of sense to get more animal manure back into the fields, where it can do good instead of wind ing up as a pollution problem. I'd like to see the humus content of the soil built up again, by crop rotation and plowing under clover or alfalfa now and then. It would stop the ferti lizers from leaching out so rapidly." First Need of All: Population Control Dr. Cole made another point. I'd heard it made before by virtually every ecologist I had interviewed. "One of our basic errors," he said, "is that we always equate growth with goodness. Everything has to keep growing-the popu lation, the cities, the industries. We have to stop growth somewhere. And, if we don't stop the population explosion, there's very little chance of solving our other problems. It's the key to the whole thing. "We have to recognize that we're dealing *See "The Revolution in American Agriculture," by Jules B. Billard, NATIONAL GEOGRAPHIC, February 1970.