Mobilizing the Fertilizer Resources of Our Soils

We are engaged in a great war. This is testimony, seemingly, that man hasn’t risen to a very great height, at least spiritually. Without being unpardonably reflective on man, suppose for our thinking we reduce him to the low level of the animal which the carnage of the war indicates and let us think of him in terms of his food as we think of any other animal life form, low though that may be.

Next to sex instinct, man’s desire for food is a bigger compelling force to drive him to action than anything else. His food is a product of the soil. His food is a fabrication by some ten or a dozen elements held in the soil in mineral combinations that must be mobilized within the soil in order to fabricate above the soil what we call food. Man is, therefore, going to be controlled in his behavior by the extent to which there is mobilized in the soil about a dozen simple chemical elements commonly found in mineral and rock combinations. Consequently, we want to see man in his behavior in that ecological picture with all other life forms wherein the fertility of the soil is at the controls. Those who are in the limestone industry are dealing with one of the ten elements–probably two if you are dealing with dolomitic limestone–that is at the control of agriculture, at the control of food, and at the control of all life, including man.

We think of food in terms of bulk, weight, volume. We seldom think of it in terms of its quality as nourishment. In the making of food, we have two objectives as to its quality; first, it should give us power and energy; but before we can use that power and energy, we must construct the body, and food must meet the second objective, namely provide growth substances.

Reduced to its chemical simplicity, the body is about 96 per cent of these four elements that find their origin in air and water. It is about 5 per cent of a list of 10 or more elements that find their origin in the soil. We have been keeping our eyes keyed on bulk. We have been keeping our eyes fixed on those four substances, namly carbon, hydrogen, oxygen, nitrogen, that are liquid or gaseous in form and that flow and move freely. Therefore, they do not represent much of a struggle for us to get them. We have not given enough attention to the other elements that are fixed in their position in the soil and to which the plant or the animal must go for their service.

We have been keeping our eyes on weather in crop production instead of on the controls that are in the soil to determine how effectively that weather will be used. Therefore all production, and thereby food production, is not a matter of the weather which flows freely. It is a matter of the mobilization of these essentials that come from the soil, at the head of which is the one element in which you men are interested; namely, the calcium. Rather briefly let us note the fact that in moving it from a plant or from vegetable matter to the body, we must raise the concentration of the hydrogen from 6 to 10 per cent; namely, an increase of about 66 per cent. In moving the nitrogen, which is the basis of protein, the key element in protein, this nutrient must be moved from 1.6 to 2.4 per cent, an increase in concentration of about 50 per cent. It looks like a big job to increase the hydrogen in our food from 6 to that in our body of 10 per cent, or a 66 per cent increase. Those of us who are a bit corpulent and concerned about our waist measure are ofttimes accused of being lazy because we don’t take much physical exercise and don’t spend much energy in that form; but we are spending considerable energy, physiologically speaking, when we push the 6 per cent of hydrogen in our food up to 10 in our body. Making fat is physiological work, and we heavyweights are not lazy. We are just building up and storing energy. Such is the struggle for even the elements, carbon, hydrogen and nitrogen that come from the air and water.

 

Table 1. Chemical Analysis of the Human Body in Comparison with that of Plants and of Soils

Origin or Source	Essential Elements	Human Body %	Vegetation % Dry Matter	Soil % Dry Matter
Air and Water	Oxygen Carbon Hydrogen Nitrogen	66.0 17.5 10.2* 2.4* ——— 96.1%	42.9 44.3 6.1* 1.62* ——— 94.92%	47.3 .19 .22* ———
Soil	Calcium Phosphorus Potassium Sodium Chlorine Sulfur Magnesium Iron	1.6* .9* .4† .3 .3 .2 .05 .004	.62* .56* 1.68† .43 .22 .37 .38 .04	0.3=       3.47* 0.0075    .12* 0.03      2.46† ——— .06 .12 2.24 4.50
	Iodine Fluorene Silicon Manganese	Trace	Trace Trace 0-3.00 Trace	.1027.74 .08

* These are involved in the plant and animal struggles to find enough to meet the high concentrations needed.

= Amounts common as the more available forms in the soil in contrast t o the total, most of which is but slowly available.

† This represents struggles by the animals to eliminate it.

 

Suppose we look at the struggle for the elements from the soil. Let us consider the plant’s struggle first. It finds .3 per cent exchangeable calcium in soil that it must double to .6 per cent in its body. That is an increase of 100 per cent. It must reach into the soil for its phosphorus that is present there in only .007 per cent and shove it up to .56 per cent or an 8000 per cent increase. Does that represent any struggle on the part of the plant? Indeed it does. Take its potassium which is found in the soil at .03 per cent. The plant must push it up to 1.6 per cent. You can see that the struggle for food on the part of the plant is much greater in the terms of soil than is man’s struggle for his in terms of the atmospheric elements that represent weather.

If we consider man’s struggle for the things from the soil he finds calcium at .6 per cent in the plant but must literally treble it or bring about a 300 per cent increase in concentration in his body. He finds phosphorus in the plant at .56 per cent, and must move it up to .9, another 100 per cent task. We can readily see that the struggle in terms of the things that come from the soil is many times greater than for those coming from air and water.

In the case of potassium, the situation is reversed. Man doesn’t use all the potassium in the plant because the plant uses potash to make carbohydrates and is well stocked. Man doesn’t need much potash. Man needs calcium to make protein, and we need to put those two nutrient elements against each other because as the soils are relatively high in potash, they grow carbonaceous foods, give fattening value to them, and make us grow fat accordingly on consuming them. As our soils are relatively high in calcium in contrast to the potash, we grow the proteinaceous vegetation, the mineral-rich vegetation that contributes to protein production and good bone building. In consequence, we have the slim, trim, boyish figure with vigor instead of the corn-fed heavyweight that is sluggish and indifferent.

We see the fattening powers in one region of the world where the potash dominates and the poor reproduction and the poor body characters prevail, particularly with reference to bone; and then in contrast are the calcareous regions that represent bone-building and body-reproduction at its best, with vigor of a high order. By producing limestone for use on the soil we are aiding in this struggle to push high the ratio of calcium to potassium in the soil and thereby to push up the reproductive powers of animals both lower and higher–including the human–and give us reproduction and growth instead of fattening powers and phlegmatic natures. May we lay that principle down for you with emphasis because we believe that it is an extremely important one. We haven’t seen it in the declining fertility of our soils and haven’t accepted the responsibility of mobilizing these resources in the soil with some of these finer far-reaching motives in mind.

We have literally been in a blind alley for a number of years on this matter of liming, we have been thinking that the lime is serving a great function in fighting soil acidity. That is a fight that ought now be over. It should have been over a long time ago. Peace along these lines ought to be declared. We are no longer liming for the purpose of fighting soil acidity. We are now liming in order to introduce calcium and magnesium as fertility elements to be mobilized for better plant and animal production.

A number of years ago in some research work, we undertook to get into this question. We drilled soybeans into the field by placing in the right half of the fertilizer drill some calcium salts that were not carbonates. One of these salts was a nitrate and another was a chloride. The third was the hydroxide–chosen, of course, with the idea of neutralizing the soil at the same time that this treatment was supplying calcium. Recall the first two. One of them carried calcium as a nutrient associated with nitrogen as another nutrient. The other carried calcium as a nutrient and also the chloride, a non-nutrient, to increase the soil acidity rather than reduce it. It is significant in these trials that in all treatments improved growth resulted regardless of whether soil acidity was neutralized or not.

Figure 1. Calcium nitrate, and calcium chloride (right to left) put into the right half of the drill made streaks of as good soybeans without neutralizing the soil acidity as did calcium hydroxide drilled solid (left half) which neutralized the soil acidity.

 

We were separating the functions of liming into its two possibilities; first, the carbonate that neutralizes acid, and second, the calcium that supplies nourishment. These treated soybeans were highly nodulated and they were very productive. There was obtained a perfect legume behavior by putting on calcium chloride which did not neutralize the acidity but which supplied calcium. In some subsequent work, sodium carbonate was used which neutralized the acidity but did not supply calcium and failed to give that result.

Now suppose we approach this matter of the function of calcium and how we can make calcium active. Let’s ask ourselves how a plant feeds, and you will recall that the botanist tells us that you can feed a plant by a solution. This is true. So there were taken increasing amounts of calcium in solution or increasing concentrations and put it into sand as one of a plant series. One cannot go very high in concentration of a solution of calcium acetate until it begins to kill the plants because of the osmotic relations. On the other hand, if one tries to feed a plant on pulverized mineral, as was done in another series using the mineral anorthite, a calcium feldspar that was finely ground, with increasing amounts of it put into the sand, there was no growth of the soybean beyond the possibility of the materials in the seed even where large amounts were used. These facts compel us to get the viewpoint that we can feed a plant by means of solution, but we can’t feed it actively enough by means of only pulverized minerals.

Figure 2. Increasing amounts of calcium (left to right) as a solution of calcium acetate may be too concentrated for plants, while calcium adsorbed on the permutite clay is not dangerous put in at much higher amounts. Calcium in the natural mineral anorthite does not break down rapidly enough to feed the soybean plants.

 

What then, is the possibility? If we put the calcium acetate through a permutite, as you put hard water through a zeolite softener, the calcium is adsorbed on the permutite. Then one. can put increasing amounts of the permutite into the sand and let the plant help itself to the calcium that is not in solution, is not in mineral crystals, but is held on the surface of this clay. The largest amounts were not large enough to be injurious, but they had to be significantly large before the plant could take off enough against the holding power of the permutite in order to get something to survive.

We are desirous that it be understood that in dealing with plant feeding we are dealing with the clay complex that absorbs the nutrients out of solution, and holds them for the plant to take off, provided it can do so by exchange of something of chemically equivalent activity. If we look at the clay and its capacity to hold nutrients by adsorption, and thereby for exchange, and if that clay is loaded as it normally is in the soil, it contains a good deal of its capacity, about half, as calcium. It contains a small amount of magnesium, a small amount of potash, a small amount of ammonia, a small amount of nitrogen, of sodium, of other elements and particularly some hydrogen or acid. As that clay becomes acid with weathering, what is happening? The elements–other than hydrogen–are going out and among them, the calcium is going most rapidly. Most of them become less but at nothing like the rate at which calcium goes out. There comes in a large amount of hydrogen to replace these that are lost. Therefore it is simple and easy to see that by driving out this hydrogen or acid by means of calcium carbonate, we are also putting back the calcium and doing the plant good while we were thinking about hydrogen as doing the plant harm.

When the soil becomes acid naturally, then what is happening? Hydrogen is coming in, but that is not the detrimental feature. The detrimental feature is the going out of the nutrients, among which calcium is going out so much faster than any of the rest of them that the ratio of calcium to anything else is radically upset. Suppose we consider the ratio of calcium to potash as it changes while the soil is being weathered or is becoming acid. As we get to an acid soil, it still may have a liberal amount of potash compared to a much more fertile soil. But there is only a small amount of calcium in proportion to the potassium. Thereby we have shifted from a proteinaceous crop producer that is mineral-rich in calcium and all the other fertility–because calcium goes fast and if it is left, all the rest are left–to a calcium-poor carbonaceous crop producer. This is a very essential principle which applies to the natural change that our soils undergo.

This principle was demonstrated experimentally. There was taken a clay that was made completely acid, and then titrated with calcium hydroxide only to the point of giving it a pH of 4.4. As more of that clay–acid as it was–was put into sand to grow soybeans, or as there was more total clay in that soil to give more root-feeding surface, there resulted healthier plants. As they were starved by giving them less clay, they were attacked by a fungus, suggesting “damping off.” In this case one might run to the drugstore for mercuric antidotes, but such evidence shows that the introduction of a little more fertility to feed the plant is a far better remedy for disease. By supplying more clay there was 100 per cent health, by withholding it and its calcium there was 98 per cent disease. This was produced simply by operating under the belief that whether it is plants or pigs…, the old adage holds–namely, “to be well fed is to be healthy.” This suggests itself as a sound principle, namely, that whenever our plants are victims of fungus diseases–and we have just recently demonstrated it on the victims of insects–we better look to our plant nutrition than to the drugstore and the chemists for antidotes of those supposed enemies.

Figure 3. Putting more clay into the sand made the difference between “sick” plants and healthy ones, even if the clay was very acid, pH 4.4.

Figure 4. Soybean growth is improved more by increasing the calcium (reading from lower row upward) than by reducing the acidity (left to right). There was less acidity from left to right in each row (pH 4.0, 4.5, 5.0, 5.5, 6.0, 6.5), but the middle row had twice as much clay and the upper row four times as much to give the plants twice and four times as much calcium. The dividing line between good and poor plants moves to the left and more acidity as the plants had more clay and more calcium.

 

In order to separate the effects of the degree of acidity of the clay from those by the supply of calcium on it, different clays were made by starting with a clay at the degree of acidity shown as pH 3.6. This acidity was then neutralized in different batches of clay to provide them in decreasing degrees of acidity, namely pH 4.0, 4.5, 5.0, 5.5, 6.0, and 6.5. Enough from each of these different clays was then taken for soybean growth to supply a given but constant amount of calcium in quartz sand. Thus it provided each pot of plants with the same amount of exchangeable calcium in one series, but on clays of varying degrees of acidity in this series. Another series was given twice the amount of clay or calcium. Another series was given four times the amounts of calcium on clays varying in degrees of acidity from pH 4.0 to 6.5. The results of the crop growth are shown in Figure 4.

Observation of the lower row, would lead one to say that the soybean plant is not sensitive to pH 6, but is sensitive to 5.5. If you were to look at the next row, you would have to change your decision and say that the dividing line is between pH 5 and 5.5. Then if you were to look at the upper row, you would say that the pH sensitivity of that crop is between 4.5 and 5. By quadrupling the amount of clay, the pH was shifted from 6 to 5, which is from 10 to 100. By using four times as much nourishment it was possible to offset ten times as much acidity. Such plant responses tell us that the plant is not influenced so much by the degree of acidity, but rather much more by the amount of fertility that is delivered. So instead of thinking about liming to fight soil acidity, one must take into consideration the amount of clay there is in the soil. As the soil has more clay, liming it will modify the degree of acidity less, but it will still deliver the same amount of calcium.

By varying the extent to which the acidity of the clay is neutralized by calcium, and by varying the amounts of each clay put into sand, one can arrange a series of plants given the same total amount of calcium but with increasing concentrations of it on the clay because of less clay required at the higher degrees of saturation. As the saturation of the clay by calcium goes up its saturation by hydrogen or acidity goes down. This is shown in the upper series of Figure 5. In the second series there is the same amount of calcium with increasing concentration as in the first, but instead of being associated with the hydrogen and, therefore, having decreasing acidity, it is associated with magnesium and there is no variation in acidity in the pot series. All of those soils are neutral. All of those in the third series are also neutral but barium, a non-nutrient is the accompaniment. Regardless of whether that calcium is accompanied by hydrogen that changes the acidity or by magnesium and barium that do not, the plant growth follows the increasing concentration of calcium on the clay in all three cases. Therefore, it is not the decreasing acidity that is responsible for the better growth. It is the increasing concentration of calcium that is the common factor in all. We submit for your consideration, then, the fact that when we lime, the crop grows better not because we removed the acidity but because we supplied or mobilized that one nutrient element, namely calcium, that normally comes out of the limestone.

Figure 5. Better soybean growth resulted from increasing the concentration of calcium on the clay (left to right) without providing more total calcium for the crop. This occurred where there was also decreasing acidity (upper row, Ca-H) or whether all the soils were neutral (lower two rows, Ca-Mg and Ca-Ba).

 

For the mechanism by which that mobilization is brought about, let us imagine that there is the root of the plant, against it is the clay as a colloid and the humus as a colloid, and then there is the mineral in lime against these. This mineral may be calcite, or any other mineral, as is illustrated in Figure 6.

Figure 6. The mechanism of plant feeding. Plant nutrients, like calcium, on the colloid are exchanged for hydrogen. As the colloid clay and humus become exhausted, the nutrients move from the mineral to the root through the colloid while the hydrogen, or acidity, moves in the opposite direction.

 

What is happening in the mobilization of the mineral nutrients? The root is going into a medium that has been subjected to rainwater leaching. If the plant nutrients on that clay had been water soluble, they would have been gone a long while before the plant root ever got there. In addition to that, if the plant had to live on only what is water soluble, the plant wouldn’t get off to a good start.

The root, however, is a growing concern. It grows and will go only as it grows. As it grows, it is respiring. It must have oxygen, and much of our soil troubles are centered around the problem of oxygen shortage for the root. It gives off carbon dioxide to make acid. That provides active hydrogen and that hydrogen is the medium of trade by which the root and the colloid deal. The plant trades hydrogen to the clay for the nutrients absorbed on it and these nutrients go into the root. The clay is, therefore, a kind of “jobber.” It trades what it has for what it gets. It gets hydrogen. It trades calcium, potash, magnesium, and all the rest of them, but calcium is at the head of the list and is the most commonly removed or exchanged.

Some work has shown that within six weeks, if only clay is present, as much as 85 per cent of some of the nutrients could be traded off the clay. What business could that jobber do with the immediately next crop if it were traded out of its nutrients to that extent? Instead of having just the root and clay together in a different experiment, the clay and the minerals were put together. As minerals there were used the silts of some of our different soils located across the East and West in the United States. It was found that if that clay was originally acid, in three months it would become neutral by breaking down some of the minerals.

There is then what one might call a mineral assembly line in the soil in which hydrogen is coming to the right and serving as the weathering agent, like any acid, to break down the mineral. The mineral is sending its nutrients down the assembly line in the other direction. Our plant production on many soils is now geared to the slow rate at which this mobilization from the right to the left is taking place.

We have another assembly line in the soil which is mobilized by the humus. When the plant grows and has made its excellent combinations of collected minerals, and, of course, tied them into chemical combinations with carbon in proteins and others, all this drops back to form humus which is a colloid that can serve as a jobber, too, but it also supplies energy for the microbial life of the soil. Microbes burn out the carbon to go to the atmosphere and leave the ash. That ash is another contribution via the humus to the mineral assembly line. American prosperity of the past has been built, not by this slow-going assembly line with delivery from the minerals only but by the combustion process of burning that natural humus reserve out of the soil.

Our westward movement in the United States–not only in politics but in food supply too, as we discover today–is built on this simple observation that the soils in the eastern United States have burnt low their humus supply and their mineral mobilization is running too slow to make beef and animal products as they once did. We may well think soils in terms of a geographical viewpoint. As Americans we have been soil exploiters. We are just beginning now to put a little back. Limestone producers are at the head of the list of those ministering to soil restoration in providing the first need for the soil.

Soil is a temporary rest stop of the rock on its way to the sea. Rainfall is the natural force moving the rock in that direction. As we start in the western United States–outside of California–with its annual rainfall from 0 to 10 inches and come eastward, the rainfall increases from 10 to 20, 20 to 30, 30 to 40, 40 to 50. By going a little southeastward we can throw some effects of temperature into the picture. It is helpful to keep in mind particularly the 20 to 30 inch belt of rainfall running north and south and the area of 30 to 40 inches just east of it. These are the areas of favorable soil development according to climate and agricultural possibilities. Rainfall is the chemical reagent that is making soil out of the rock. It is developing a soil at the lower ranges of moisture and destroying the soil at the higher ranges of moisture and temperature.

When the water falls as rain most of it goes through the soil but much of it evaporates. Professor Transeau of Ohio has taken the rainfall and balanced against it the evaporation for a free water surface and put the results on a percentage basis. In northern Missouri, for example, we have a rainfall that is only 80 per cent as much as the evaporation would be from a free water surface. As a consequence, our rainfall doesn’t go through the soil so extensively nor leach the soil so highly of its basic material, or of its minerals. The central part of the United States, with much of its rainfall coming in the summer and with its winds blowing from the West to the East, has had its soils developed under high evaporation to reduce the leaching and destructive effect of that rainfall on the mineral supplies in the soil. Consequently, the region through the central portion of the United States known as the Cornbelt belongs to the prairies located farther West.

Figure 7. The rainfall of the United States (exclusive of the western coast) increases as one goes eastward and southeastward from the central part. It gives us an East and a West, and divides the East into a North and a South. Soils are in construction in the West and in destruction in the East.

 

If one looks at the soil map of the United States one can immediately see that there are the divisions of the United States into an East and a West. The East is divided into a North and a South, but not by politics or color lines, but rather because of different soil situations. It is our different soils that feed us differently to make us different. We are as we eat and that is not only our disposition but our philosophy of life. We are reflecting differences in our national politics by different soil regions but are prone to believe that some other things than soils are the cause.

In the western United States, we have soil in mounting construction as one goes eastward. There is being made more clay with more rainfall. That clay is holding by absorption more of the essentials for plant growth. It is able to give more to the plant in exchange. More soil construction gives increasing productivity until one reaches the central United States. As one goes eastward and southeastward from there the clay begins to lose what it has adsorbed on it, and substitutes hydrogen for its calcium, its potash, its magnesium, and other nutrients. Acidity begins to come in and gives the soil region of much acidity, or according to the limestone consumption map of the United States, the region where the consumption of this remedy for calcium-deficiency is centered.

Figure 8. The effectiveness of rainfall in leaching the soil and removing its fertility is reduced as evaporation increases. The ratio of rainfall to evaporation from a free-water surface points out why the cornbelt has soils and crops more like the prairie states. (Map by Transeau.)

Figure 9. Soils are all stages of the rock en route to the sea. Soils are in construction in going from western to central United States and then in destruction as the rainfall and temperature go still higher. Plant distribution with different food values of the forage, animal distribution, animal diseases, and human ailments fit into this soil pattern. (Soil map by C. F. Marbut)

 

In going to more rainfall there is the breakdown of that clay. In fact, it is another clay, a red clay that is mainly an iron hydroxide. The silica goes out of it. It has aluminum and iron in dominance. It is distinctly red in contrast to clay in soils under less rainfall and less heat. It has a small capacity to hold anything. It won’t hold hydrogen either, and so the South has said, “No, we don’t have acidity. Therefore we don’t need to fight it. We don’t need lime.” But as is well known every southern mother has been needing calcium when she says that every baby costs her two teeth. The southern picture in terms of calcium for agricultural use is behind the schedule of needs because we have been fighting soil acidity instead of giving the matter of better nutrition and healthy reproduction the normal support that we might by mobilizing some of the essentials out of the soil.

The study of our own soils in a little greater detail points out that in the West we have alkalization where the rock is broken down to liberate only the sodium and potassium. Then with more water, those go out and a calcium and magnesium soil results. Any of you who have ever traveled through the West will remember some of the magnesium sulfate and other salts in the water.

Then as we come eastward, therefore, we have calcification. Still higher rainfall is taking the calcium out and putting hydrogen in and we begin to recognize soil acidity, because we have a clay that will hold much hydrogen. The fact that it will hold the hydrogen is not a bane but a blessing. It will hold much fertility if we will put it there. It will mobilize lots of rock if we will put it there, because the active hydrogen will break down the rock to keep the mineral assembly lines delivering nutrients to the plants.

In the West, there is a relative dominance of the calcium in a proteinaceous vegetation, a vegetation that made buffaloes by the thundering herds for the pioneers that went West. In contrast the poor Pilgrim Fathers were so delighted to find a few turkeys on the eastern coast that they declared a Thanksgiving and we have had to celebrate it ever since.

Perhaps you can see that this soil picture is basic to the ecology of life. Out on the range, the animals are hardy. They reproduce freely. In the eastern United States, we find cattle troubles in the milk sheds of the cities where every cow apparently must have a veterinarian wait on her when she tries to go back into another turn of milk production. Human diseases are beginning to give the same picture, and the studies of our draftee rejections are going to give some marvelous revelations if we will put the soil picture under them by careful study of the data.

Where do we produce the proteinaceous vegetation and where the carbonaceous vegetation? The forests of the United States outline the areas of carbonaceous vegetation. Does the South with its pines begin to stir up your interest in those little children that have infantile paralysis and hookworm and all else that goes with it on soils that were naturally of such a low fertility level as to grow mainly wood? Do you begin to see that when you have soil that isn’t developed yet and hasn’t much to give, or when it is exhausted too far, you are at the tail end of the possibility of a good human existence in terms of a healthy body? Do you begin to see the prairie vegetation on top of a calcium-laden soil as the place where the buffalo roamed? Do you begin to see why limestone has received attention only in the regions marked by presence of soil acidity when it ought to have it in many other regions? We have been giving our attention to acidity when we ought to have been looking at the need of life for the nutrient calcium.

Our national programs have much ahead of them if we will begin to get at them in terms of some of these fundamentals. The fertilizer has gone on the soil near the shores of the East and Southeast. The South has been using extensive amounts of calcium in its superphosphate and remedying its troubles in part, not by thinking calcium and sulfur, however, but by thinking phosphorus and using superphosphate.

The native vegetation, as pictured by Dr. Schantz, across the State of Kansas, with its 17 inches of rainfall in the west and 37 in the east, immediately makes it evident that there is an increase in tonnage of the vegetation per acre as the rainfall goes up. But what about the quality of that vegetation? The quality of the vegetation is portrayed in Dr. Schantz’s putting into that picture the lime line within one foot of the surface and one foot thick in western Kansas and its location at greater depth and its disappearance from the soil as one comes eastward.

Figure 10. Across Kansas with its increasing rainfall from 17 to 37 Inches from west to east there is an increase in the tonnage of vegetation produced. There is also an increased loss of lime and other fertility from the soil. The buffalo, however, was interested in his feed according to the soil fertility giving it quality, and not according to the rainfall, that gives it bulk. (Drawing by Schantz.)

 

Immediately one can see that it is easy to let the plant’s process of photosynthesis make plant bulk, but when the buffalo stayed out West and didn’t come East we recognize that biosynthesis within the plant and not only photosynthesis made the products that the buffalo wanted. Had the buffalo merely been interested in packing his paunch with bulk, he could have wandered eastward because there are no mountains and no rivers to obstruct his travel in Kansas. Instead he stayed out where we gave his name to the grass by which he lived. We gave buffalo grass the name not to a great extent east and west but to a long line north and south, because that is the soil type where the buffalo found the plant making in itself the things he needed to be that tremendous brawn, that tremendous bone, and that liberal capacity to reproduce in great numbers.

Do you begin to see that the soil is at the controls and that our responsibility is to mobilize out of that soil and through the plant shell of a factory those things that let that plant do something besides making carbon, hydrogen, and oxygen into wood or fuel, but rather to make those complexes that you can call proteins and vitamins and what-not that build bones, healthy bodies, and give us the feeling of well-being?

Across Kansas and in agreement with the soils of higher fertility contents we find the protein content of the wheat going from 10 per cent up to 17 and 18 per cent from East to West. In many cases we have said this higher protein comes because of less rainfall. However, if we take the soils in Missouri, much farther East and will give them the fertility, they will make as hard a wheat, as protein-rich a wheat as Kansas ever grew. It is because these more eastern soils have been leached of their fertility that their wheat plants are making mainly starch and the same variety of wheat plants in the West are making much protein. Can we begin to see the ecology of various life forms with the soil as the basic mineral resource that determines whether photosynthesis will do something besides make fuel as poor as pine wood in the South? Do you begin to see the central belt of the United States as the great center in which some of these health-giving foods are created because the fertility of the soil has been put there? Do we begin to see the responsibility we have to that land, as we must, to shift from mining it to giving some national attention to managing it if our national health and our vigor and our capacity to repopulate is going to continue?

Suppose we look at soils in terms of an international aspect. Let’s picture to ourselves those places in the world that duplicate the climatic conditions in central United States, and where are they? They are all bordering some hard wheat belts, just as we have it. Civilizations rise only when man doesn’t spend all of his time working for his food. Man writes books, gives us poetry, carves statues only when his stomach is full. When he need not spend all of his time searching for food, it is then that he builds civilizations. In the United States we have a hard wheat belt and the rainy side of the country to the east of it. We made a great move when we followed the advice of that great editor in New York City when he said, “Go West, young man.” American prosperity was built on the fact that we went West, because we went to a deeper soil, more laden with humus, better stocked with the reserve mineral supply, and not because we were nomadic in nature. We have exploited the soil possibilities and have gone as far as we can go. Like the waves rushing up on the beach, the arid western soils are now throwing us back to the East. The flotsam and the jetsam are being left in the wake, as that book by Mr. Steinbeck, “Grapes of Wrath” tells us so effectively.

In Europe, the situation is the same but reversed in directions. There is the hard wheat belt and the low rainfall over in Russia and the wet side in Europe to the west. In that there is much reason why Hitler speaks of his “Drang nach Osten” and its food by way of fertile soils still unexhausted. We see then in the temperate zone those soils which are not at high enough rainfall to be exhausted of their mineral reserve. They are not so cold but what the rocks and minerals will be developed into soils. They are not so hot as to be seriously exhausted. Life for humans is a matter of the ten essential elements as fertility in the soil and not a matter of the weather.

If we move to the temperate zone of the southern hemisphere we have exactly the same picture as in the North, but in limited amounts, because the land areas are limited. There we have New Zealand and Australia, the agricultural resting point for the British Empire; Canada, another toe-hold for it; southern Africa, one of the last places with unexploited mineral resources in the soil; and then Argentina, the squabbling place because Germany is reaching there at the same time with the British Empire for the products of some fertile soils. When we squeeze our enemy out of Argentina, we are squeezing one of our Allies, consequently Argentina’s precarious political situation when it connects with the European “empty stomachs”, which as the Russian proverb puts it, “know no laws.”

Isn’t it possible that the Japanese may not have been interested in possessing the many islands in the tropics? Were they probably not much more interested in some of the areas of hard wheat in Australia? Might we not well think of the international struggle as a case of man at the low level of fighting for something to eat and his finding those food-producing places, not in terms of land areas alone, but in terms of the possibilities by which the mineral resources in the soil can be mobilized to catch sunshine and build the food by which he reproduces and lives.

Figure 11. Human health goes with the soil and its fertility. Courtesy F.S.A. Scene from Wadesboro, N. C. Photo by Post.

 

That the soil determines the quality of our food, is well illustrated by some studies with spinach–that much maligned human forage. This crop makes a glorious growth as long as it gets plenty of nitrogen, but may contain little of the minerals for which it is supposedly eaten. Two series of five soils were set up with increasing amounts of calcium but with all else constant. One series was given the calcium as chloride, sulfate and other salts so as to leave an acid condition in the soil. The other series was given its calcium as hydroxide to make the soil neutral. Spinach was grown on these two series of soil with increasing calcium content, one an acid soil and one a neutral soil.

When the spinach crop was harvested and chemical analyses made, the calcium in the crop grown on the acid soil went up as a straight line function of the amount of calcium put on the soil. The magnesium, too, even though it was a constant amount in all soils, was higher in the plants as more calcium was applied. This gives another principle, namely, that lime is a mobilizer of other substances of nutritive value, seemingly through its effects on the root in terms of its function as a permeable membrane. Here is good basis for the old jingle that says “Lime and lime without manure, make father rich but son poor.”

As the soil was given more calcium, the plant was more active in making oxalate, one of its synthetic organic products we recognize in rhubarb, and other vegetables. More calcium meant more manufacturing business by the plant, but, unfortunately, the oxalate makes the mineral elements calcium and magnesium insoluble and indigestible. Nevertheless, the amount of oxalate in relation to that of magnesium and of calcium was not so high in the crop on the limed but acid soil but that the spinach would have supplied the baby some digestible calcium and magnesium in spite of the high oxalate.

Where the soil was limed to make it neutral, the situation was quite different. The increased calcium in the soil did not put increased amounts of calcium into the crop. What is more significant, it made such a large amount of oxalate in relation to those two minerals that the oxalate made every bit of the calcium and the magnesium insoluble and indigestible. Consequently, if some unsuspecting baby would have had this spinach jammed down its gullet, that spinach would not only have been worthless to that baby as a deliverer of magnesium and calcium, but it would have precipitated and made indigestible and unusable even some of the calcium in the milk that might have been taken with it.

Plant distribution on the earth, so readily interpreted in terms of climate, and chemical composition of vegetation and the services of it in nourishing the lower animals as well as ourselves, all seem to point out our responsibility in understanding this whole business of food production that starts by mobilizing the minerals in the soil. Our responsibility is not a matter of mere yields as bulk per acre but of giving some consideration about the quality of the stuff we produce in terms of the essentials for growth and reproduction that must come out of the soil. When we think about our responsibilities in managing this land, we are fundamentally interested in mobilizing out of the soil those things that do more than catch air, water and sunshine that make fuel, or that make for fat. Let’s think about the things that grow healthy bodies, make sound bones, and prevent rickets, when, after all, human health and human well-being go with the soil–either up or down–and its fertility.