Hidden Hunger & Soil Fertility
HUNGER IS NOT a new problem. Next to the sex instinct, it is the principal force driving man and beast into action. It projects one into areas where he had not previously ventured either in body or in mind.
Today we understand hunger as world-wide in extent and importance. We are examining deeply enough into it to distinguish its “hidden” forms. We recognize these as due to shortages, not so much in the bulk of the food as in its nutritional qualities. We have not yet been able to tag all the different organic and inorganic compounds that provide these qualities, but have come to believe that many are grown into our foods. Consequently, we are thinking about deficiencies in the fertility of the soil as responsible for the failure of food to fully satisfy our body needs.
Hidden hungers are not experienced by man only. Even the microbes, the lowest forms of life, within the soil have their hidden hungers. Organic matter of the soil, which is the source of their energy food, accumulates in some deficient or acid soils while the microbes literally starve. In the face of abundance, hidden hungers exist for nitrogen, calcium and other elements of soil fertility. Under such conditions there is a surplus of bulk and a shortage of protein and growth-promoting compounds.
Sweet clover, fed as a green manure to the soil bacteria may cause hidden hunger for potassium. While this popular soil-improving legume grows and feeds ravenously on calcium, it can make bulk despite meagre supplies of potassium. It grows well enough on a pile of crushed limestone suitable for fertilizer use. But, it has manufactured little potassium into itself to satisfy the microbes. Thus the corn crop, which is expected to benefit from this green manure as a supplier of nitrogen actually is robbed by it of potassium in the process. In such cases, the soil microbes, too, are struggling to cover their hidden hunger.
Mature sweet clover residues of late summer, and straw left after the combine, plowed under before seeding a wheat crop, represent hidden hungers of microbes for nitrogen. The wheat crop also suffers but its hunger is not hidden. However, we do not appreciate the fact that the wheat crop “eats at the second table” and that the microbes in their hunger for nitrogen are literally passing this hunger on to the wheat crop.
Corn shows the same nitrogen hunger but this is usually interpreted as excessive thirst rather than lack of nitrogen. Thus the weather, over which we have no control, is made the scapegoat while we do nothing about the deficiency in the soil. It is important to note that both the corn and the microbes have plenty of energy food. Both, however, suffer from hidden hunger for small amounts of nitrogen by which their surplus energy foods can be converted into proteins and their diets balanced.
Even the lower forms of green plants, like the plankton in our fish ponds, suffer hidden hunger. In turn, the fish with their hunger for “grow foods” in more and better plankton do not multiply or grow so rapidly as when the fish ponds have proper food supplies.
Wild animals well up in the biological scale have their hidden hungers, too, though the fact is not always associated with the fertility of the soil. Animals that are strictly grass-eaters are not commonly found on the highly leached soils of the tropics. Instead buffaloes, elephants, antelopes and others of like species are found on the prairies and savannas. They subsist on mineral-rich soils, where natural legumes abound, which under cultivation produce hard, high-protein wheat.
The roaming of wild animals and their ravaging of farm crops usually indicates an effort to satisfy hidden hungers. In leaving the forest to graze on fertilized land, the deer signals his recognition of better nutritive values in the feed growing there. When cattle break through fences to get at the virgin soil of the highway or railroad right of way they reveal their instinct for nutritive food.
An animal’s ability to detect differences in soil fertility—almost beyond our means of chemical detection, is not based on minerals. The animal is not looking to plants as haulers of minerals but as synthesizers of organic and organo-mineral complexes that build the animal body and supply energy. We have catalogued some of these complexes, but can we doubt that many yet remain unlisted? Much more is unknown than known about the nature and function of food factors, and the main provokers of hidden hunger may yet be unknown.
How shall we combat hidden hunger? Fortunately, we are better able to combat these hungers at the point of origin, that is in the soil, than at any later stage. Prevention is simpler than cure. At that point the problem is no more complex perhaps than supplying one or more inorganic elements. Cure the hidden hunger of microbes and plants and you prevent the hidden hunger of animals and humans. The further removed from the soil the more nearly insurmountable the problem of supplying the diet with essential minerals, vitamins, amino acids, etc.
Lespedeza hay grown after phosphate application and fed to sheep caused them to grow fleeces that were low in fat or yolk and that scoured out too poorly to be carded except as broken fibers. Yet the same kind of hay grown on soil treated with both lime and phosphate helped grow fleeces of heavy yolk and wool that scoured well and carded out as fibers of good quality. Treating the soil was simple; but to figure out what supplement to feed the sheep to make better wool is not so simple. Cure is extremely perplexing but prevention is as simple as, in this case, liming the soil.
In our thinking about “diseases” both empirical and scientific knowledge are influencing us to think less about cure and more about prevention by ministering to sick soils. Once the mind thinks in terms of soil fertility, observations come rapidly. Calves eating plaster, not the exposed first coat but the hidden last coat in a fine barn, prompted a farmer to ferret out a magnesium deficiency in his soils. Prompted by curiosity and intelligence to use some magnesium as a fertilizer he started a train of apparent miracles, including the curing of scours in calves, and some reduced mortality, less mastitis in the cows, better alfalfa, better corn, and other blessings on his farm.
When other major and minor mineral elements given to cattle make them negative to the blood test for brucellosis; and when medical research is pointing to similar suggestions for improvement of undulant fever patients, these are no longer hidden troubles. Attention to the soil as the point of origin of diseases as deficiencies, as major hungers, calls for major attention by more of us than those of the curative professions alone.
It can be truthfully said that rapid progress is being made in recognizing hidden hungers. Many of them are now being prevented because they are being diagnosed as originating in our declining soil fertility. Foremost among the gross decline is the loss of protein synthesis by plants. Soil treatments are no longer desirable only because they produce more bulk per acre. They are applied to increasing acres also because they add to the nutritional quality of the crops, which relieve a long chain of hidden hungers coming up from the soil through the entire biotic pyramid to torment man at the top. For better reproduction of farm animals, and for the better health for them and for ourselves as well, we are becoming increasingly concerned to know more about soil fertility as the guarantee of good fortune.
The disturbing hidden hungers are hidden mainly from our thought, our recognition, and our full appreciation of their origin. They are not hidden from our physiology, nor from our mental processes, when as little iodine as a fraction of a grain coming up from our soils through plants is all that “stands between us and imbecility”.
It is a good sign for the future that we are coming to realize that our hidden hungers are provoking deficiencies in mind as well as body. We are coming to think about keeping up the soil in order to keep us mentally able to realize that our hidden hungers are pointing to the soil fertility as ready means for their prevention.