Our Soils and Our Foods

Because soils seem to be everywhere and because plants with their roots in the earth are all about us, we take soils and crops on them all for granted. But now that there is no more “new land” available, and that food prices and other limitations are bringing many of us “back to the soil,” we are beginning to see that we cannot continue to take our soils for granted. We are beginning to see the soil as the source of our food and to consider the latter in relation to the fertility of the former.

Man Too Far Removed From Soil

Man, at the top of the pyramid of all the different life forms, has the help of many of these in reaching out over extensive areas of soil to collect his essential food elements and food compounds. There are some dozen or more different chemical elements coming directly from the soil. Man himself travels far to eat the fruits of many different soils. Then, too, he is omnivorous, that is, he eats most everything including vegetable, animal, and even mineral, to increase the possibilities of giving to his body each of the many essential elements found in the soil and as these have compounded–by means of sunshine–the four essential ones coming from air and water. Plants send their roots searching through the soils so they can do their collecting and fabricating of man’s foods. Animals search through the plants to collect and construct still further for him. He selects from all these foods–both plants and animals–the bulk and concentrates what he needs for energy, for growth, for reproduction, and for other complicated body performances. All of these performances and body processes are too often taken for granted and with no recognition of the soil as a helper or a hindrance. We have seemingly been far removed from the soil. Nevertheless, the changing conditions in economics, in agricultural production, in the capacity of our soils to provide essentials, and in the nutritive quality of our foods are all bringing us to think more about the soil.

In our agricultural production the weather has always been considered a very important factor. While the daily variations of the meteorological conditions, which we call the weather, have long been recognized as important, the climate, which is the average of the weather over a long time, is even more important in controlling both the kind and the quantity of what we can grow.

It is the long-time effect of rainfall and temperature combined as climate that determines what kind of soil has been produced by weathering the rocks going to make it. The kind of soil determines the kind and quality of the foods that can be grown.

Soil Fertility Pattern Results From Climatic Pattern

The soil is a temporary rest step by the rocks on their way to solution and the sea. How far the rocks have travelled on this journey depends on how much rainfall and high temperature have been crowding them along on their route. In regions of low rainfall the soils are still rocky and sandy. There has not been enough rainfall to carry rock decomposition so far as to make much insoluble clay. Nor has there been enough water to wash the soluble materials away. Consequently the soils are alkaline. They are loaded with too many salts to permit good plant growth even if we make up the shortage in seasonal rainfall by irrigating the crop.

Coming eastward in the western part of our country means more soil construction. It means coming from the desert and its soil that supports very little life to where the bison once roamed and where wheat and livestock grow today. It means that legumes have grown bountifully enough in the past so that the soils are well stocked with nitrogen. It means soils that have not been leached. They have not had most of their fertility washed out, nor have they had hydrogen take its place on the clay to make them “acid.” It means mineral-rich and productive soils because the lesser rainfalls have made enough clay and have loaded it with fertility. But those lower rainfalls have not carried that fertility down through to leave an acid clay subsoil below a shallow surface soil layer, which is the common condition in eastern United States under high rainfall.

Increasing rainfall as one goes eastward from the midcontinent, particularly in the northern part of eastern United States, means soil destruction. This results because there is more rainfall than evaporation. This puts considerable water down through the soil. The percolating water loaded with its carbonic acid takes the lime, magnesia, potash, and many other nutrient elements off the clay by putting hydrogen or acid–a non nutrient–in their place.

With much rainfall to have weathered the rocks extensively, there is enough clay residue in the soils to make us say, “They are heavy.” They require much plowing and working to make a good seedbed. Fortunately, their clay is still somewhat like the original rocks. It is still a silicate and has a high filtering capacity. By this property it can catch and hold nutrients by taking them out of any solutions, should they come along. This same high exchange capacity of the clay for nutrients can mean a high degree of acidity in case the fertility has been washed out. But it is the same big capacity to hold fertility if we put it back into the acid soil. Such are the clays and soil conditions in the cooler, northern half of eastern United States, where higher rainfalls mean soil destruction in terms of better foods.

If the climate is a combination of higher temperature as well as higher rainfall, as is the case when in eastern United States one goes from the North to the South, then the rocks and even the clay are broken down much more completely. They do not leave a gray silicate clay. Instead a red, iron aluminum clay results. This clay does not have much filtering or exchange capacity. If solutions of nutrients pass through, it does not take the nutrients out so effectively nor hold them for rapid exchange to the growing plant roots. It will not hold much acid either. Consequently in the southeastern states it has often been said, “Because there is so little acidity in the soil no lime is needed to remove it.”

Such reasoning fails to appreciate the difficulty of growing crops on soils of which the clay has so little exchange capacity. It disregards the high needs for the calcium in lime as a fertilizer even if those do not need the carbonate of lime to neutralize any acidity. Such soils are low in capacity to grow mineral-rich, protein-rich crops. They grow wood instead. They require considerable fertilizing to grow even the simple carbohydrates like sugar, and like cellulose in cotton fiber. So much of the fertilizer is washed out to require fertilizer for every crop following.

The soils, then, in the western states are still rich in unweathered minerals. Their clay is well, stocked with nutrients. They have a high producing power for proteins. In the eastern states the soils are highly weathered with the clays in the soils of the cooler regions quite different from those in the tropical soils. This climatic pattern that makes the soils from the rocks determines, then, what nutrient elements the soils contain. Thereby it determines also how well those soils will feed our crops, our:animals, and ourselves.

Carbohydrates Plus Proteins Versus Mainly Carbohydrates

When alfalfa grows dominantly in Colorado soils; when sugar cane grows abundantly in Louisiana; and when the rubber tree quickly takes over in Brazil; are these merely matters of differences in temperature or rainfall with no dependence on the soil?

Alfalfa is a protein-bearing, mineral-containing forage of especially high lime content. It demands large supplies of mobile nutrients from the soil. It grows well where lower amounts of rainfall have not depleted the lime and other fertility elements from the surface soil. When planted on soils in regions of higher rainfall, it demands lime and other soil treatments for its successful growth.

Cotton delivers mainly carbon products in its fibers, oily seeds, and shrub-like form. It demands less fertile soils than alfalfa. Lime helps cotton but has not been an absolute requisite to grow it. Cotton responds more to fertilization with potassium, the nutrient which encourages carbohydrate production in plants more than protein production which is encouraged by calcium. Cotton herbage is not a forage feed for livestock, then, because the products it manufactures under its soil limitations are not necessarily feed.

The rubber tree is another carbon- or wood-delivering crop. Its product, rubber, is neither edible nor digestible. Like other forest trees, it uses much less fertility than alfalfa for growth and each annual supply of that is dropped back to the soil almost wholly in its leaf crop. Through decomposition, this fertility supply in the leaves completes the cycle as it rotates from the soil up into the tree to the leaves and from the fallen and decomposed leaves back to the soil again. While making this cycle it does little more than make wood. Even that product consists mainly of air and water elaborated by sunshine into compounds of fuel value only for flames and not for the physiology of animals and folks.

Pedigree is No Determiner of Plant’s Chemical Composition

Perhaps you have never thought much about the variation in chemical composition of the food crops in the various parts of the country according to the climatic soil pattern. It is true that we have different plant species, alfalfa, cotton, and rubber on different levels of soil fertility. It is true that some are giving us both carbohydrates and proteins as balanced diet. Others give only carbohydrates. More significant, however, is the great fact that the same kind of crop has different chemical compositions on these different soils. The plant’s pedigree is no control of this. So when Nature has washed out a soil by pouring excessive rainfall on it, or when we have taken out its fertility by crop removal and no fertility return, there is a change in chemical composition in such common crops like corn or wheat, for example. Unfortunately, that change is not so much in the carbohydrate part where it would register as recognizable change in bulk. Rather such change consists of the reduction in the protein and mineral contents, a smaller and unrecognized, but very significant fraction of the crop. Plants keep right on making carbohydrates as fuel and fattening foods for us on less fertile soils. But they do less in converting those carbohydrates into proteins and mineral compounds that help grow bodies and help in their reproduction.

The protein concentration in wheat, often spoken of as its “hardness” illustrates this fact very well. On Missouri soils under her 40 or more inches of annual rainfall which makes them badly leached and acid, wheat does well to have as much as ten per cent protein. Going westward across Kansas, according to data of 1940, the protein in the wheat there went up from the above figure in eastern Kansas to one as high as eighteen per cent in the western part. Putting extra fertility into the Missouri soils at the proper times made equally as high a protein wheat there, according to experimental trials.

While some one may believe that the dry weather of western Kansas makes wheat “hard,” the dry year of 1936 in Missouri did not push the protein in the latter state’s wheat crop up to where it was a competitor with the former state’s “hard” wheat. Rainfall as seasonal water is not in control directly of the concentration of protein in the wheat. Rather it controls indirectly through the fertility it has left in, or removed from, the soils in the course of developing them from the rocks during centuries past.

This variation in the chemical composition of wheat is a part of the soil fertility pattern. High protein accompanies the starch or carbohydrate farther west. On coming eastward there is still plenty of starch as indicated by the high yields as bushels per acre, but there is a decrease in the protein. On the lime-laden, nitrogen-providing soils this grain crop makes carbohydrates and converts a good share of them into protein by the help of this extra soil fertility. On the less fertile, commonly called “acid” soils under the higher rainfall of the temperate zone, the crops make carbohydrates as the bushels per acre measure it. But they do not produce much protein.

Measuring Fertility by the Plant Bulk Produced Makes Protein the Food Problem

Consequently then in feeding our animals we are faced with the problem of purchasing the protein supplements. These must be grown, and brought from soils somewhere. These once consisted of the by-products of the wheat milling business that also has gone west. Along with the problem of feeding the animals on such soils comes the fact that human foods are not so mineral-rich when the nutrients from the soil required by the plants to synthesize their proteins are not there.

Any plant that grows is making carbohydrates by that process. These are built from air and water by sunshine energy. The plants that make proteins need the fertility from the soil to help make these complexes which the animals can only collect from the plant, but can not synthesize themselves. Carbohydrates pile up readily as bulk to give big yields as tons and bushels. But when plants are converting this sunshine product into proteins, they do not pile up such yields so rapidly. Our selection of a crop merely for big bulk as yields has brought into prominence those crops that are mainly producers of carbohydrates. It encourages the “soft” wheats and the low protein corn. It has encouraged production of the fattening foods and less of those for body-building and fecund reproduction.

The pattern of the chemical composition of feeds and foods reflects the pattern of soil fertility beneath and in control of it. Less weathered soils in the Midwest grow alfalfa, high protein wheat, beef cattle and sheep. Those same soils were growing big crops of protein when they had thundering herds of bison on their short grass. The more weathered soils in the east central and eastern states grow carbohydrate crops and fattening power as we recognize readily in corn and hogs. Such soils pile up the crop bulk, but they give us the problems of protein supplements and the troubles in animal reproduction.

In the quality of our foods we must recognize the soil and its fertility in control. By the traverse from the more fertile soils in the West to the less fertile in the East there is the change from both carbohydrates and proteins to mainly carbohydrates. When less fertility means more carbohydrates and less proteins we can understand that the depletion of the soil is responsible for the decline in the protein of corn from 9.5 to 8.5 per cent during the last ten years of higher yields and much-mentioned hybrid vigor. The chemical composition of our food suggests that it takes its pattern for the country from the pattern of the fertility of the soil by which it is created.

“To be Well Fed is to be Healthy”

Because we have given so little thought to health and so much more to disease, the national health pattern has not very generally called itself to our attention. We have been slow to believe that the pattern of variable health is a reflection of the variable nutritional values of our foods that go in good measure with the variation in the fertility of the soil. That we should grow cattle in the West and fatten them in the East has not been considered a pattern of animal health even by some of the folks of the experiment stations. They have been prone to consider this a matter controlled by economics. Likewise some folks have been content to believe that the same economics, rather than the exhaustion of the soil fertility, is responsible for the westward march of high-protein wheat from the Geneseo River Valley in New York–where big milling works were originally set up–across the continent as far west as Kansas to date. While economics are connected–more as a result than a cause–with such changes, one needs only to look deeper and consider the question, “What controls the economics?”

Certainly if one can grow only fattening feeds it will be more economical for the farmer, but healthier for the animals, to use them to hang fat on the animals grown near to adulthood somewhere else than to face the odds of trying to breed and raise them on such feeds, bolstered by imported protein supplements, mineral mixtures and drug concoctions. When our dairy calf crops in eastern United States are less than sixty per cent of the cows bred; and when in Missouri, for example, we get to market less than sixty per cent of the pigs the brood sows deliver as their litters, there is the suggestion that some significant economic facts are coming into play. Unfortunately, such is bad economics. There is the further suggestion that a nine month period of gestation by the cow and life span of but six months of the porker are even too extended a period for us to carry successfully our responsibilities as animal feeders. These bad economics seemingly are crowding the marketing dates for our livestock closer and closer to the animals birthdays. Instead of attributing these troubles to disease and calling for more veterinarians, it looks as if we need to see the health pattern of our animals and of ourselves in relation to the map of soil fertility as it makes the map of crop composition, especially the proteins and minerals.

Our Teeth and Our Soils

Health records of the draftees for the Army are numerous for areas as small as a county. There is no shortage of data that might well be studied on a national scale to give helpful information. Data for the condition of the teeth of nearly 70,000 inductees into the Navy in 1942 are a good illustration of what such records tell us about our soils and ourselves in terms of dental health.

The Navy reported its records of the number of cavities and fillings per mouth gathered as a means of estimating the number of dentists needed to keep the masticating section of the Navy in a good state of repair. These data were assembled for the different sections of our country. When arranged by longitudinal belts two states wide and considering these in going both westward and eastward from the Mississippi River, this map of dental health of our young men reflects the soil fertility pattern clearly.

For the area two states wide adjoining the Mississippi River on the west each Navy inductee had, as an average, 8.38 cavities, 3.70 fillings, or a total of 12.08 caries in his mouth. Farther west by two states, each mouth reported 8.80 cavities, 4.30 fillings, and 13.10 caries. For the west coastal states the corresponding figures were 9.10, 6.40 and 15.50, respectively. Thus in going from the mid continent westward the numbers of cavities and fillings of the teeth per inductee mounted by more than 25 per cent as poorer health.

Much more serious are the implications concerning the health of the teeth according to these data, in going from the midcontinent eastward. For the belt of two states wide just east of the Mississippi River there were 10.06 cavities, 4.89 fillings, or 14.95 total caries. Much worse are the conditions for the Atlantic belt of states where the records give 11.45 cavities, 6.10 fillings, and 17.55 total caries.

While we have none too good a health condition of our teeth even in the midcontinent with its soils of maximum protein-producing power in the better fertility supply, the teeth are poorer as one goes westward from there to the less developed soils, and much poorer in going eastward to those excessively developed and less fertile. Only the soils more fertile in terms of making more protein in plants give better health of the teeth.

Sciences of Soil and Nutrition Will Bring Better Understanding of Food Values

We are gradually coming to believe that the soil, in terms of the food it grows, is a controlling fact in the various results of agricultural creation including ourselves. That the fertility pattern maps out the nutritional quality of feeds and foods is not yet widely recognized or appreciated. That it should be is not so expectable when we have been measuring our agricultural output in terms of only bulk and weight increase rather than in terms of nutrition, reproduction, and better survival by the species.

By subscribing to the production criteria of more tons and more bushels, we have watched the crops but have forgotten the soils that grow them. When the dwindling fertility makes protein-producing, mineral-providing crops “hard to grow,” we fail to undergird them with soil treatment for their higher nutritional values in growing young animals and nourishing ourselves. The soil fertility as help towards more protein within the body, as protection against microbial and other invasions, has not impressed itself. Instead we have taken to the therapeutic services of protective products generated by animals, and even microbes, in our bloodstream as disease fighters. The life of the soil is not attractive. The death of it is no recognized disaster. Consequently better soil for better food is not yet a universal ambition. The provision of proteins is our major food problem. Carbohydrates are easily grown. Any growing plant is synthesizing carbohydrates mainly from the elements of the weather by sunshine energy. For the output of these energy foods very little soil fertility is required in terms of either the number of chemical elements or the amounts of each. But, in order for the plant to convert its carbohydrates into proteins by its life processes and not by the sunshine power, calcium, nitrogen, phosphorus, and a long list, including the trace elements are required.

It is in the protein synthesis and in the reproduction of life, that the control by the soil of the nutritive quality of foods is pronounced. Our ignorance of this control is suggested when we classify as proteins anything that gives off nitrogen upon burning in sulfuric acid. By this we include nitrogenous compounds that are not proteins. Yet we recognize about two dozen different amino acids as components of the proteins. We know that life is impossible without providing the complete collection of at least eight of them. When even the trace elements, manganese and boron, applied to the soil at rates of but a few pounds per acre for alfalfa increase the concentration of these essential amino acids in this crop–especially those amino acids deficient in corn–there is evidence that the nutritive quality of this forage is connected with the fertility of the soil.

Newer Criteria of Food Values Emphasize Soil Significance

The assessment of the contributions by the soil through only the ash analyses of the crops, has left us ignorant of the numerous roles played in the plant’s synthetic processes by the elements of soil origin. In believing that we need “minerals” according to such analyses of our bodies and our foods for their inorganic contents, we consider the soil as the supply of these and the plants as conveyors of them. We conclude therefrom that limestone fed to the cow in the mineral box is the equivalent in nutritional service to lime used as soil treatment coming through the plant.

Likewise have we been content to accept and use average figures for ash analyses. In the same year and in the same state, for example, the protein of wheat has varied from a low of 10 to a high of 18 per cent of the grain. Ash elements may double or treble their concentration in the crop on one soil over that on another. Such variations go unappreciated if we are content to believe that “plants are good feed and good food if they make a big crop.” Crops that are doing little more than to pile up carbohydrates, as was demonstrated with soybeans, make big yields of bulk. But when fertilized to produce proteins, the hay yields are smaller. To be content with the above simple faith is to be as agronomically gullible as the youngsters content with the knowledge of reproduction that credits this process to the delivery services by the stork.

Our reluctance to credit the soil with some relation to the nutritive quality of our feeds and foods is well illustrated by the belief persistent during the last quarter of a century, namely, that the acidity of the soil is injurious and that the benefit from liming lies in its helps in fighting this acidity when, in truth, it lies in its nourishment of the plants with calcium and its activities in their synthesis of proteins and other food essentials. To say that we don’t believe there is a relation between the nutritive values of feeds or foods and the fertility of the soil is a confession of ignorance of all that is to be known of this fact and is not a negation of it.

Only Fertile Soils Feed Us Nutritious Foods

As yet we do not appreciate the pattern of soil fertility in the United States, that in pre-colonial days was allowing only wood crops, or forests, on the soil in the eastern half. It grew protein as meat in the bison on the buffalo grass in midcontinent, and in some scattered areas farther east like particular valleys of Pennsylvania or the present race horse area of Kentucky. It permitted corn in the forested New England when each hill was fertilized with a fish. Corn on the eastern prairies grew well without such stimulation.

We may well ask whether the soil in its fertility pattern is of no import relative to nutritive quality of what it produces (1) when we grow cattle and make beef protein more effectively today in the former bison area; (2) when that areas is now growing the high protein wheat; (3) when we fatten cattle farther east on the more weathered soils and combine this speculative venture with pork production that puts emphasis on fat output by carbohydrates and the lessened hazard by marketing these smaller animals nearer their birthday; (4) when soil fertility exhaustion has pushed soft wheat westward; (5) when the protein in corn has dropped, because of soil exploitation, from an average figure of 9.5 to 8.5 per cent; and (6) when the pattern of the caries of the teeth of the Navy inductees in 1942 reflects the climatic pattern of soil fertility. Such items related to the national pattern of soil fertility suggest that many of our agricultural successes (or escapes from disaster) have been good fortunes through chance location with respect to the fertility of the soil when we have too readily, perhaps, credited them to our embryo agricultural science.

When a crop begins to fail we search far and accept others if they make bulk where the predecessor didn’t. We credit the newcomer with being “a hay crop but not a seed crop.” If it cannot guarantee its own reproduction via seed, we call it feed for the cow. With the cow’s failure to reproduce under such poor nutritional support we, apparently, economize on the bull’s energy by resorting to repeated artificial inseminations. The grazing animals have been selecting areas according to better soils. They have been going through fences to the virgin right-of-way. They have been grazing the very edges of the highway shoulders next to the concrete to their own destruction on the Coastal Plains soils. All these are animal demonstrations that the nutritive quality of feed is related to the soils that grow it. But to date, the animals rather than we as their masters, have appreciated this fact most.

Shall we keep our eyes closed to the soil’s creative power via proteins, organo-inorganic compounds, and all the complexes of constructive and catalytic services in nutrition? When the health and functions of our plants, our animals and ourselves indicate the need, isn’t it a call for agricultural research to gear production into delivery of nutritional values related to the fertility of the soil rather than only those premised on bulk and the ability to fill? By directing attention to the soil for its help in making better food, we may possibly realize the wisdom in the adage of long standing that tells us that “to be well fed is to be healthy” and that good nutrition must be built from the ground up.