THE NOT-SO-GOOD EARTH
Man is robbing the soil of the minerals it needs to grow good nourishing food. Result: We can eat well, yet still be starved
C. FRED BODSWORTH
DURING THE war a strange and somewhat startling letter came to the University of Manitoba in Winnipeg from a farmer in a
rural area of the province. He claimed there was hardly a man over 45 years of age in his district who was capable of doing a full day’s work. Everyone seemed to tire easily; men, women and children alike were frequently sick; tooth decay was abnormally common and children grew slowly.
The farmer said that the local doctor had been unable to explain the high prevalence of ill health which existed in the area; in fact, the doctor was sick just as frequently as his neighbors. “What ails us all?” the farmer asked.
The letter finally came to Prof. J. H. Ellis of the soils department. Prof. Ellis obtained samples of the soil from several farms in the area for laboratory analyses. He found that one thing was common to every sample—an extremely low percentage ot phosphorus.
Prof. Ellis knew that this would cause grains and vegetables grown on that land to be low in phosphorus too, and, since it was an area in which the farmers lived to a large extent on their own produce, he suspected the ill health was the result of a diet deficient in phosphorus. He recommended liberal applications of phosphate fertilizers to the land, particularly to the vegetable garden plots. And he described his findings to the local medical officer of health, who started giving phosphate tonics to those whose health was most impaired.
Prof. Ellis was able to report: “The medical officer of health has informed us that the treating of the soil and the adding of phosphates directly to the diet of some of the residents seems to have overcome the ill-health problem.”
These Manitobans have learned out of their own experience a lesson that is slowly coming to nutritionists and agriculturists throughout the world that the nutritional value of the food we
eat is determined to a great extent by the mineral richness of the soil in which it is grown. In nutrition laboratories in North America and Europe, scientists are learning today that a carrot or a cabbage or a grain of wheat can be a source of growth-producing and health-inducing proteins, vitamins and minerals, or it can—without any difference in size or appearance—be deficient in these and composed largely of carbohydrate starches and sugars which are of value only as body fuel. The character of the soil influences the nutritional value of our milk, butter, eggs and the meat, too, for if a cow or a hen lives on mineraldeficient and vitamin-deficient pastures and grains, its milk or its eggs will also be mineral-deficient and vitamin-deficient.
The 14 Essential Minerals
AGRICULTURISTS are beginning to realize that size of yield is not the only criterion of the productivity of land, and that 30 bushels of mineral-rich and vitamin-rich wheat per acre may actually be a better yield nutritionally than 50 bushels of wheat that is deficient in those values.
The chemical hocus-pocus that goes on between soil, plants and animals in the production of the various foods we eat is more complicated than a Tl-General income-tax form. After a century or more of study, scientists still have only about half of the jigsaw puzzle fitted together.
Animal and human foods can be broken down into four elements: 1, fats and carbohydrates; 2, proteins; 3, vitamins, and 4, minerals. Carbohydrates are our fat and heat producers; they are compounds of hydrogen, oxygen and carbon which are manufactured in plant leaves. Proteins are the main ingredients of living animal tissue, essential f~>r growth and keeping body tissue in repair; they are composed of hydrogen, oxygen and carbon,
with a liberal serving of nitrogen and a tiny bit of sulphur stirred in. Vitamins (13 of them have been chemically identified so far, but scientists say there are some 25 food substances that might be regarded as vitamins) are also compounds of hydrogen, oxygen and carbon with sometimes minute quantities of nitrogen, sulphur and chlorine added; most, but not all, are produced by plants. The vitamins are essential in human and animal nutrition, and so are some 14 mineral elements, which form the fourth important class of food. Our blood must have iron, for instance, before it can absorb oxygen from the air; without iron we get anaemia. Our teeth and bones need calcium and phosphorus. Iodine is required by the thyroid gland. Where do the plants get the chemical building blocks to make these substances? Carbon, in the form of carbon dioxide, is breathed in by green leaves from the air. Hydrogen and oxygen come from water picked up by the roots. Nitrogen, too, originates in the air but plants are unable to Like it in its gaseous form and have to absorb it in the form of nitrate salts through their roots. These are the “big four” elements in animal and human bodies. Together they form 96%, of the weight of a living animal. A 150-pound man is
97.5 pounds oxygen, 27
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pounds carbon, 15 pounds hydrogen and 4.5 pounds nitrogen. But from here on the jigsaw puzzle is incompletely filled in. We have accounted for only 144 of that 150 pounds. If we puil apart those remaining six pounds we will find around two and a half pounds of calcium, one and a half pounds of phosphorus, nine or 10 ounces of potassium, eight ounces each of sodium, chlorine and sulphur, around one ounce of magnesium, about one-fifteenth of an ounce of iron and then much smaller quantities of manganese, iodine, copper, zinc, fluorine, aluminum and no one knows for sure what others.
Man can’t get his mineral diet by sprinkling copper or iron filings on his porridge. These minerals, to satisfy mankind’s finicky digestive system, must be eaten in the form of complex chemical compounds which are produced from the raw elements by plants. And plants have to pick up their mineral raw materials from the soil. There is no other source.
On soils low in minerals, plants may still be able to produce healthv-looking growth, yet their tissue will be very low in minerals. Low in vitamins, too, for the presence of certain minerals seems to be essential in the manufacture of several plant-produced vitamins. After adding a pinch of manganese to certain fields, one U. S. food processor claimed to have harvested tomatoes with triple the usual vitamin C content. A little boron (the main ingredient of borax) added to soil around apple trees in northwestern U. 8. has doubled the vitamin A content of the fruit.
Dr. G. Howell Harris, professor of plant nutrition at the University of British Columbia, reports that the calcium content of cabbage has been found to be four times as great in one district as in another. And in the case of iron content, there may be 50 times J as much of this mineral in a cabbage produced on iron-rich soil as in one
grown on soil where iron is deficient. In U. S. experiments, the iron content of milk has been increased from 21 to 55 parts per million by proper fertilizing of the soils where the cows were pastured.
We have followed the mineral trail from our dining-room table back to the soil—but where did the soil get its mineral elements? Originally the earth’s surface was a crust of hard rock, the type of rock varying with the locality but containing in most cases minute traces of the mineral elements necessary for plant and animal growth. Millions of years of rain, wind and frost caused this rock crust to crumble into a surface layer of clay and sand which still contained the same quota of minerals that had existed in the parent rock. Simple plants started to grow in this clay-sand composition, they died and decayed, eventually producing after many years the mixture of humus and rock particles which is our soil of today.
Robbery in the Fields
There are a few localities where the soil is deficient in certain minerals because the rock itself from which the soil came never had those minerals. But most soils in their original form had a proper balance of the essential minerals. Deficiencies are nearly always due either to heavy rainfall or to improper farm cropping. In areas where rainfall is heavy the soil may be robbed of a share of its minerals by leaching— water soaking through the soil dissolving and carrying away the minerals. But farm cropping is the biggest mineral robber. Every crop uses up a bit of the soil’s mineral store and if nothing is put back to make up the loss the soil becomes that much the poorer. Nature intended every plant, and every animal which ate those plants, to die and return their elements to the soil that provided them in the first place. But instead we send our plant products all over the world and the money we get in exchange is fine for commerce, but not worth a hoot to the soil. We have
great sewage disposal systems which every day send tons of soil-given elements down to the oceans. And when we die we are buried in boxes guaranteed to withstand nature for 50 years. Sentiment, sanitation and commerce are playing a gyp game with our soils.
The Hidden Hunger
Many areas are known to have become so deficient in certain minerals that diseases among humans and farm animals have resulted. But that’s not the whole story. Dr. William A. Albrecht of the University of Missouri, North America’s pioneer and leader in the study of soil and health, says that the soil of the continent as a whole has degenerated imperceptibly, that our fields may be still green, but that their greenness camouflages the fact that their production of real food values is steadily diminishing. Albrecht says that the American population as a whole is becoming a little more poorly fed each year. We are being stalked by a hidden hunger, a hunger not yet serious enough to cause nutritional diseases, but sapping our strength and health, lowering our resistance to disease, retarding the growth of our children and cutting down the reproductive fertility of our population. Albrecht and several other investigators believe that the decline of soil minerals is one of the causes—possibly the main cause — of the vast increases during our generation of the degeneraative diseases such as heart ailments, rheumatism, appendicitis, cancer, diabetes and mental diseases.
Studies show that current fertilization practices in North America are falling far short of soil needs. Most chemical fertilizers contain only phosphorus, nitrogen and potassium, and the soil’s calcium needs are now frequently being met by applications of lime. Thus, only four out of that list of 14 or so minerals are being provided for.
But even those four are not being
taken care of adequately. Let’s consider phosphorus as an example. In 1946 the U. S. National Resources Board estimated that the U. S. was losing annually more than two and a half million tons of phosphate from its soil through harvesting and cattle grazing, and almost three million tons more through leaching and erosion. Yet the U. S. is putting back into its soil in fertilizers only two and a half million tons of phosphates a year. As a result, 80% of U. S. soils are said to be suffering from phosphorus deficiency and in Canada the situation is reported to be the same.
Most Canadians have a diet which includes foods from many parts of the world. Perhaps the vegetables of our own back-yard garden are low in one or two minerals or vitamins, but we stand a good chance of making up this loss with other foods grown elsewhere and imported. In many parts of southern U. S., however, farmers live almost entirely on what they grow themselves and the health of large sections of the population is being undermined by soil infertility. During the war in one southern state seven out of 10 army draftees had to be rejected on physical grounds; in Colorado, a rich-soil state, seven out of 10 were accepted for military service.
Sickness in the Sunshine
Several years ago Florida medical authorities became alarmed at the high incidence of anaemia among rural children in many parts of the state. In some areas 96% of children were anaemic. This in sun-drenched Florida, where diets included large amounts of home-grown fresh fruits, vegetables and milk!
At first intestinal hookworm was thought to be the cause of the anaemia. But when the hookworm was eradicated the anaemia still persisted. At this stage Dr. Ouida Davis Abbott of the agricultural experimental station at Gainsville stepped into the investigation. He wondered about that bountiful diet of fruit and vegetables. And he commenced a wide-scale chemical analysis of the state’s soils.
He discovered that practically all of Florida’s farming soil was low in iron, and that where the iron content was lowest, anaemia was most prevalent. Doctors commenced giving iron-containing tonics to Florida children to fill in the gap until agriculturalists could build up the minerAl health of the soil by means of special fertilizers. Since then anaemia in Florida has been steadily declining.
Anaemia isn’t always a simple matter of “soil minus iron equals anaemia.” Recent experiments at the University of Wisconsin have shown that humans and animals are incapable of putting the iron of their diet to work unless there are also minute daily traces of copper and cobalt in the diet as well. Thus, in New Zealand it was proven that “bush sickness” among cattle, a form of anaemia, was due not to a lack of iron, but to soil deficient in copper. Livestock, and presumably man too, would waste away and die if copper or cobalt were totally removed from the diet, yet the daily requirements of these minerals are microscopic.
Studies of Canadian soils and their relation to nutrition have been limited. During the war the Ontario Agricultural College at Guelph and the Hospital for Sick Children in Toronto carried out an intensive survey of the vitamin C content of fruits and vegetables grown in Ontario. In tests using tomatoes they found that the amount of sunlight was the factor which influenced vitamin C production most; there was also evidence that the vitamin C
content varied on different soils. When tomato plants started at Guelph from the same batch of seed were sent out to five widely separated sections of the province for transplanting, the tomatoes subsequently harvested varied as much as 100% in the amount of vitamin C they contained.
Dr. J. H. L. Truscott of Guelph, who was in charge of the survey, said they were unable to determine what soil features were beneficial for the production of vitamin C in plants. Plant nutritionists in the U. S. have reported that manganese in the soil favors vitamin C production. When Dr. Truscott compared tomatoes grown on the manganese-deficient field with tomatoes grown where the manganese content of the soil is normal, he found no appreciable difference in vitamin C content.
But whether or not manganese helps plants build vitamins, there is no doubt that this mineral is essential for healthy plant growth. The OAC experts were called in when onions and red beets grew poorly with yellowing tops in certain areas of the Erieau Marsh near Lake FJrie. They decided a deficiency of one of the minor minerals was responsible. They selected four different plots where the crops were growing poorly, sprayed one with a solution containing iron, another with boron, the third with manganese and the fourth with a “shotgun” mixture containing all the other minerals known to be required by plants. The onions and beets which got the manganese spray flourished, the other plots showed no improvement.
A similar test of soils in several parts of Okanagan Valley, B.C., where apple yields were low, revealed a deficiency of boron. Some Okanagan orchardists tried feeding their apple trees boron by boring holes in the trunks and packing powdered borax into the holes. This worked, but sometimes injured the trunks. The recommended method now is to apply boracic acid to the soil around the trees.
Sulphur, a mineral that goes into plant proteins, is rarely deficient in soil, yet at least two parts of Canada have been found to lack it. In southeastern Manitoba it is necessary to add gypsum (calcium sulphate) to certain soils, and, on one of the islands off the B. C. coast, it has been reported that pasturage low in sulphur has caused malnutrition and disease among sheep.
The Manganese Mystery
The mineral fertility of North American soil is highest on the Canadian and U. S. prairies where rainfall and resultant mineral leaching is light and it becomes lower as you move eastward or westward toward the seaboards where rainfall increases.
When Dr. Albrecht compared statistics of tooth decay in U. S. military personnel he found a striking correlation between the amount of decay and the mineral fertility of the soil from which the inductees came. U. S. tooth decay is lowest in the Midwest where the soil is highest in calcium and phosphorus.
Years ago U. S. raisers of beef cattle learned that Herefords were more reproductive, grew more rapidly and produced heavier and healthier bodies in the West, but that fattening them for the market on western soils was difficult, sometimes impossible. When cattle grown to maturity on western soils were moved to soils in Eastern U. S., they ceased bone and body growth and fattened rapidly. Those western soils produce forage and grains high in proteins and minerals, the food values which build tough, healthy, well-boned bodies, whereas the eastern
soils, lacking minerals, produce crops which are mainly carbohydrates and starches, the fat-producing food values.
But in Eastern U. S. there is one famous island of rich soil—the bluegrass country of Kentucky. It isn’t an accident, nor is it due to the proximity of the big-money race courses, that Kentucky produces the world’s finest race horses. It is because Kentucky soils were developed from rock originally very rich in phosphorus and calcium.
Sometimes They Poison
A paradoxical sidelight to this story of soil minerals in nutrition is that many of those minerals, which, in minute traces, are as essential to life as the air we breathe, are actually Jekyll-Hyde characters as poisonous as arsenic if we get too much of them.
Nitrates, phosphorus, iodine and copper are all poisonous in large doses.
Recently on a farm in Central Manitoba, cattle were being fed oat sheaves from the stook. As long as the sheaves were being taken from the upland portion of the field there was no trouble, but as soon as the sheaves were obtained from a low spot in the field the cattle became ill, and some died. The symptoms were recognized by Prof. Ellis to be those of nitrate poisoning. When the oat straw was analyzed it was found to contain nitrates in an amount well above what an animal could safely eat. Water running off the high land had carried nitrates to the low patches of the field where it had accumulated.
The evidence is still complicated and sometimes contradictory, but the general picture is clear—our health, our very survival, depend immeasurably on
minute traces of minerals in the soils that grow our food. And through wastefulness, the mineral strength of the world’s soils is steadily diminishing. What the soil scientists call “hidden hunger” today may become widespread malnutrition in the years ahead if the mineral needs of our agricultural land are not met.
Several years before the recent war a Swiss scientist said: “Europe will
always have trouble with those Prussians. There is something in the soil of Prussia which grows people with that fighting instinct. European peace is unalterably linked up with the minerals of the soil.” He was accused of fanciful daydreaming. But soil science has moved rapidly forward since his statement was made. If he made the same statement again today, many an expert might listen with new interest. ★