Soil Science Spelled It Out A Whole Century Ago

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From GENE LOGSDON

An organic farm marketer brought me a strange book to read and I can’t get it out of my mind. It was written by Cyril Hopkins, an agronomist at the University of Illinois in 1911. Already a century ago, science had committed the wisdom of the ages about maintaining soil fertility (Hopkins quotes Cato, Varro and Virgil from ancient Rome) to the finely wrought analysis and statistics of science. Soil scientists knew very well how to practice sustainable farming a century ago but then as now many people, including some fellow scientists, paid little attention. The strangeness of the book comes from the author’s efforts to write “The Story of The Soil” in the form of a novel, embedding his treatise on soil science in a more or less fictional love story.  He had already written a factual book on how to restore and maintain fertility in America’s declining soils but, surprise, surprise, hardly anyone read it. I suppose he figured that maybe people would pay attention if a little sexual intrigue were woven into his pages of dry facts and figures about manure, lime, rock phosphate and clover rotations and what happens when you don’t do it correctly. I doubt his ploy worked except with those of us who think sustainable farming is a pretty sexy subject all by itself.

At the beginning of the twentieth century there was plenty of evidence that yields of farm crops were in decline, despite all the blazing glory shouted from the rooftops about the limitless fertility of our soils. All that was staving off a clear realization of that fact was that for two centuries and more, we always had new land to move to and repeat the process of mining the virgin nutrients out of it. Hopkins addressed that reality directly, piling up enough statistics and case histories to choke a dinosaur. Farming for profit, farming to feed a growing population, required returning to the soil the fertility lost when crops were taken off the farm.  Intelligent cultivation, legumes in the rotations, green manure, animal manure, and replacing minerals for those lost by cropping were all essential. Hopkins was “organic” not because he was against chemical fertilizers but because he thought they would always be too expensive. Rock phosphate, natural calcium and raw potash were cheaper and got the job done with intelligent cultivation and proper rotations. But his overall take on soil fertility was chilling. No matter how clever the rotations, or how scrupulously the farmer tried to use all the manure he had available, the soil could not maintain itself without outside additions of nutrients if crops were going to be removed to feed, clothe and shelter increasing populations. It is fun to try to figure out ways to make a farm totally self-subsistent but it just ain’t so, said Hopkins.

It is hard to keep in mind that already in 1911, farming in America was already two and a half centuries old. My home farm here in Ohio had been cultivated for fifty years longer than the land I worked in Minnesota in the 1950s and you could tell the difference. The first fields on the east coast were cultivated around 1634 and those farms were for a century quite profitable. But by 1910, many thousands of those acres lay idle. No hue and cry was being raised, except for a few like Hopkins, because new land to the west had always been available. Against the evidence which Hopkins kept giving, cornbelt farmers and even some agronomists without the perspective of history, thought their land was timelessly fertile just because they hadn’t had time to use up the native nutrients yet. Hopkins predicted inevitable famine as had occurred throughout history when land “wore out.” He was famously wrong because he did not see the enormous role that mined and manufactured fertilizers would play in making his worries unfounded. But a century later, we surely must start thinking about how to keep our fields fertile without what still seems to some as an unlimited supply of these off-farm fertilizers. Or perhaps in the long run, these fertilizers will become, as Hopkins believed, too costly and the poorer people will starve again.

The most insightful passage in the book, it seems to me, goes like this: “I keep in mind always that we are feeding much grain to domestic animals, an extremely wasteful practice so far as economy of human food is concerned; because as an average, animals return in meat and milk not more than one fifth as much food value as they destroy in the responding grain consumed; and as we gradually reduce the amounts of grain that are fed to cattle, sheep and swine, we shall also gradually increase our human food supply. Ultimately our milk-producing and meat-producing animals will be fed only the grass grown upon the non-arable lands and possibly some refused forage not suitable for human food or more valuable for green manure, unless we modify our present practices…”

What courage it took to say something like that right when agriculture’s idolatry of grain was soaring. Could Hopkins have been the first prophet announcing the kind of grass farming that would rise in popularity a century later? Or will he still be wrong, not seeing that the amount of mineral fertilizers available is so great that we can not only feed humans and livestock with grain but our cars too?
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