CALCIUMBy WM. A. ALBRECHT

UNIVERSITY OF MISSOURI COLLEGE OF AGRICULTURE

COLUMBIA, MISSOURI

Reprint No. 8

LEE FOUNDATION FOR NUTRITIONAL RESEARCHMilwaukee 1, Wisconsin

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Made in United States of Americalbortetal V t. katier•o Tonlimias !no The Los41

Vol. 3, No. I, December. IOU

CALCIUMBY WM. A. ALBRECHT

CALCIUM is at the head of the list ofthe strictly soil-borne elements re-quired in the nourishment of life.

It is demanded by animal and human bodiesin larger percentages of total diet than anyother element. Its own properties, as forexample its relative solubility in some forms;its pronounced insolubility in others; itsease of displacement from rock and soils bymany elements less essential, and the multi-tudinous compounds it forms; all make it themobile one of the earth's nutrient ions.

These properties are responsible for itsthreatening absence from our surface soilsthat are bathed in the pure water of rainfall,and for its presence in the water at greatersoil depths in the distressing amounts thatmake it appear as stone in the tea-kettle or aspost-bathing rings in the bathtub.

These same properties, that seemingly im-pose shortages and hardships have givencubic miles upon cubic miles of limestone ingeologic sea deposits to be later uplifted asland areas widely disiributed in close proxim-ity to the soils now suffering shortages ofcalcium needed for plant and animal nutri-tion.

While calcium is moving by aqueous aidin this cycle from the surface soil of our landto the sea and back to our soils again, thisvery nomadic habit makes possible its serv-ices in nourishing life. Like other naturalperformances, it does work while runningdown hill. If maximum benefits to life are toaccrue while this natural cycle continues, wemust understand it and help to fit life into it.

An understanding of calcium and its role

in the nutrition of life is the start in gettingacquainted with the first on the list of allthe soil-given elements. Its behavior bidsfair to be profitably elucidated through thehelp of our observations of animals, animalassay methods, and other bio-chemical be-haviors. When all the other soil-givenelements are similarly studied, they will nolonger remain as micro-nutrients beyond ourgeneral understanding as they must when theresearch light has no more candle-power thanthat of simple chemical analysis. Calciummay well be the "test case" or "pilot plant"experience to guide our thinking and under-standing of all the other nutrient elements ofthe soil for nutrition of microbes of plants,and of animals.

Chemistry has long been the science ofanalysis. Nature has presented herself assomething to be examined, to be taken apart,and to have its parts measured, named, andclassified. Functional significance of eachpart was assigned as fast as experimentalprocedure could study each as a single vari-able while all others were held constant.Only recently has chemistry become thescience of synthesis. Its synthetic effortsare now giving us dyes in manifold colorsand fibers of rayon and nylon for fabrics thatfairly rival the rainbow itself. Nutritionalminerals and medicinal compounds as com-plex as the vitamins themselves are nowproducts of the chemist's skill.

Nevertheless, nutritional studies still moveforward mainly on the pattern of analyticalprocedures. Many arc the parts and thefactors in nutrition that remain unknown.

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2. THE LAND

of calcium in the soil has long been the soilscientist's index of the degree to which thesoil has been developed or to which the rockshave moved towards solution. As rocks arebroken down to form soil by increasing butnot large amounts of rainfall, there is anincrease in the soil's content of active cal-ciupt. Then as the larger amounts of rainfallgo higher and temperature increases alsothere is calcium depletion. Life forms,whether of the lower, like the microbes, orof the higher, like plants, and animals, allare part of this calcium picture. The dis-tribution of the different plants and of thedifferent animals as well as their densities ofpopulation take thcir ecological patternvery much according to the calcium supply.The United States divide themselves readilyinto the East and the West, according to thelime content of the soil. The dividing lineacross central United States puts lime -richsoils to the west and the calcium-deficientsoils, to the east. This is also according tothe lesser amounts of rainfall to the west andto the higher rainfalls and temperatures tothe east, these differences having been sorelated as to weather the soils just enoughto leave those in the West with calcium, andto carry the weathering to the point of theremoval of the calcium in the East. Highertemperatures and rainfall as in the southeast,not only remove the calcium but change theclay complex so that it has little holding orexchanging capacity for any of the soil min-eral elements.

In these facts there is the basic reason forcalcium deficiency and many other deficienciesin the humid tropics. Here is the basic rea-son for the confinement of the population ofthe wet tropics mainly to the seashoreswhere fish return the flow of soil fertility inpart from the sea back to the land. Suchfacts account for the sparsity of populationin the humid tropics and yet we marvel atthe tremendous vegetative growth of jungledensities. We forger that its contributionfor human use is mainly wood or fruits, whichif not actually poisonous have little food

value and at best only drug value as thecoffee, the cinchona, and the alkaloids. Itis this larger soil picture with its highlightsof calcium presence and its shadows of cal-cium absence that makes the pattern to whichall life, whether microbe, plant, animal, orman, must conform.

Microbes as the agencies of decay testifyto the level of the nutritional conditions bytheir rates of destruction of the debris whichthey rot or on which they feed. Pine needlesdecay slowly because they are grown on acalcium-deficient soil and are consequentlydeficient in this clement essential in the dietfor microbes, and deficient in all the nutritivevalues associated with calcium in plants.Timothy hay and timothy sod decay slowly.Clover hay and clover sod rot quickly."Clover and alfalfa hays" says the farmer,"are hard to make because they spoil soquickly." This is merely saying that suchhays, as products of soils rich in calcium andtherefore themselves rich in this element,allow the bacteria to multiply faster, ornourish themselves better. Consequently,they consume clover and alfalfa hays morerapidly than they consume timothy or pineneedles. Cattle choices agree with the mi-crobial choices.

Rapid decay of certain substances points tothese as balanced diets for microbes and is anindex of chemical composition and nutri-tional value for higher life forms that we toooften fail to appreciate. We have beenthinking of the disappearance of the debrisas it rots and have not been measuring thegrowth of the microbial crop. Microbes, asa kind of guinea pig, for quick evaluation ofthe dietary contributions of the substanceson which they feed, offer a neglected scien-tific technique for judging much that mightbe considered human food. Insects can servelikewise. If neither microbes nor bugs carefor certain substances should these be con-sidered as of food value for higher life forms?Whole wheat flour "gets buggy" so muchmore readily than white flour and by justthat much is it a more wholesome food.

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CALCIUM

I

We arc still wondering how many goldeneggs can be laid by that great goose known asNature. The list of carbohydrates, proteins,fats, minerals, and vitamins, has had in-creasing numbers of compounds within eachof these to be given particular emphasis.A list of a dozen or more minerals comingfrom the soil has given each importance farbeyond the magnitude each of them repre-sents as a percentage of the body compositionor of our daily diet. The vitamins of recentrecognition as essentials on the dietary listhave already increased in number until atotal of about fifty is certainly going to drivemany people to the drugstore. Three spe-cific fatty acids are now listed, and somethirty amino acids must be ingested if nutri-tion is to be without some health troubles.

Synthesis has not yet been much used as atechnique to help in our undrstanding ofbiological behaviors. We have not yet for-mulated the ideal toward which we are striv-ing because normal bodies and good or per-fect health are yet widely unattained. Theanalytical procedures and single-clement con-trols are still in vogue, unsatisfactory thoughthey may be. The isolation of one essentialcompound and the demonstration of its essen-tiality by abnormalities its absence invokes,is still the main procedure in nutritionalstudies. Plant physiology, likewise, demon-strates the plant troubles when, for example,the calcium supply is varied, or when phos-phorus is reduced, or either is completelywithheld. All the separate items on theessential list have had their individualeffects demonstrated, and we are • mappingthe world in terms of their individual ab-sence. Little has been done, however, tovary two or three elements at the same time.The number of combinations would run theexperimental trials into legion, and conse-quently such experiments have not yet beenundertaken extensively.

But such multiple variations are the situa-tions in Nature where all the soil-givennutrients, for example, may be varying during

the life or growth cycle of a single organism.It is impossible, therefore, in natural per-formances to segregate the effects of separateelements. They can be evaluated only as asummation in terms of the final plant oranimal. It is for this reason that we mustresort to the bioassay method. It becomesnecessary to use the animals themselves toobtain more gross results of value in terms ofour own life before all of the intricate indi-vidual processes can be learned and life itselfsynthesized thereby.

IINutritional thinking, however, is moving

forward rapidly. It is not limited to com-pounds like the carbohydrates or proteinsand the chemical reactions they undergo. Itis giving detailed attention to the catalyststhat speed these reactions, if vitamins can beconsidered in this category. Body catalystsfor improved mineral management, like thy-roxin for example from the thyroid gland andthe activities of the parathyroid in controlof the calcium and phosphorus in storage andin circulation, they are bringing into thelimelight the importance of supplies of theseelements as well as their catalysts.

Calcium behavior in nutrition is no excep-tion to this concept of complex interrelationwhen its supplies in the bones, in the bloodstream, and in the alimentary tract may bemoved through this series in either directionaccording to certain relations of its amountsto the supplies of the catalyst, vitamin D,excercising control. Then when there are adozen soil-given elements, each - with itsvariable supplies and possible catalyzed be-haviors to be synchronized, the possibilitiesfor shortages or deficiencies multiply them-selves quickly. Attention to calcium canonly be in terms of its deficiencies as grossmanifestations, when all of its many functionsare not yet catalogued.

The soil is formed from the rocks and theminerals by the climatic forces of rainfalland temperature. The presence or absence

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CALCIUM

3

- Calcium for microbes in the soil's serviceas a plant food factory has only recentlybecome appreciated. Legumes cooperatewith nodule bacteria for the appropriationof nitrogen from the air in many soils onlywhen calcium is supplied as lime. Not onlythe plant, but the legume microbe too, makeshigh demands for calcium. The microbeseparated from the plant must be given liberalsupplies of calcium if this cooperativestruggle for nitrogen or protein is to be suc-cessful.

IIIMicrobial decay processes within the soil

by which nitrogen as ammonia is convertedinto nitrate also depends on the calciumsupplied. Unless the clay of the soil, forexample, has calcium present in liberalamounts, this conversion of nitrogen doesnot proceed rapidly. The function of cal-cium, as it makes the phosphorus of the soilmore effective, was suggested by microbialbehaviors. With calcium and phosphorusabsorbed on a clay medium, the growth ofcertain microbes made the medium acidwhile other, but closely similar, microbesmade it alkaline. This difference occurredbecause both calcium and phosphorus arebrought off the clay and into solution withthe result that intermittently one or theother of these dominates over the other;phosphorus dominating to make the mediumacid, calcium domination to make it alkaline.Microbes apparently separate both calciumand phosphorus at the same time from theabsorption forces of the clay but consumeone or the other differently after this separa-tion to bring about the acidity or the al-kalinity. Here arc calcium and phosphorusin the microbial diet, and here they arcclosely associated in their nutritional serv-ices just as they are found associated inplants, and just as they function together inanimals mainly as the compound of the differ-ent calcium phosphates.

Microbial nutrition suggests itself as in-dicator of soil fertility and therefore of plant

and animal nutrition. Microbes, as theygrow rapidly and rot vegetation quickly, orconversely as they grow slowly and rot itslowly, indicate the soil nutrient supply byrevealing the composition of the productsgrown by that soil. Pine needles decayslowly. Oak leaves decay slowly, but elm,linden and other soft wood leaves decayrapidly. The Swiss farmer selects leavesfrom the portion of the forest with the softwood trees for bedding litter for his cows andgoats because these leaves rot more com-pletely in the manure than oak leaves do.The service of the leaves in decay when mixedwith animal excrement and in the return, oftheir nutrients to nourish the grass arejudged by the Swiss farmer through thismicrobial indicator. The rate of decay canbe taken as a universal indicator of the nu-trient balance for microbes and therefore asbalance for higher life forms.

The organic matter produced on a soil andgoing back into the soil reflects by its rate ofdecay the plant composition and thereforethe soil fertility producing it. The size ofthe microbial crop as reflected by its activityand like any other vegetation is determinedby the nutrients being mobilized in the soil.If calcium is deficient there, then the organicmatter grows a less proteinaceous composi-tion or is mainly of carbonaceous content.Such vegetation is a poor microbial diet.It reflects this fact when it accumulates orremains for a longer time while the pro-teinaceous, or more calcium-rich decays morerapidly.

The microbes, as lower plant forms, giveus the ecological pattern of higher plantsserving to nourish higher animal forms.They point out, in general, that the vegeta-tion produced on soils amply supplied withcalcium is mineral-rich and proteinaceousto serve the microbes well in their nutrition.On the soils deficient in calcium, the vegeta-tion is carbonaceous, protein-deficient, min-eral-deficient, and lacking in many organicand mineral complexes requisite not only formicrobes but for the higher life forms as well.

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4

THE LAND

Microbes give us this larger ecologicalpicture in ,agreement with the soil map of theUnited, States. Prairie soils or calcareoussoils, with their proteinaceous and minera-rich vegetation are in the.West. and forestsoils and carbonaceous vegetation are in theEast. Calcium is the index factor associatedwith these differences. As a very helpfulfactor, it needs to be given recognition andattention in connection with the largerpicture of crops and foods of correspondinglyvariable nutritional values produced on thesedifferent soils.

IvThe delayed appreciation of the significance

of calcium in plant nutrition may be laid , atthe doorstep of a confused thinking aboutliming and soil acidity. The absence of limein many soils of the non-temperate zone haslong been known. Lime in different formssuch as chalk, marl, gypsum, or land plaster,has been a soil treatment for centuries. Limewas used in Rome in times B. C., and theRomans used it in England in the first centuryA. D. Chalking the' land is an old practicein the British Isles: The calcareous depositslike • 'The White Cliffs of Dover" were ap-preciated in soil improvement for centuriesbefore they were commemorated in song.Liming the soil is a very ancient art, but avery recent science, of agriculture. It waswhen Leibig, Lawes and Gilbert, and otherscientists began to focus'attention on the soilas source of chemical elements for plantnutrition that nitrogen, soluble phosphate,and potassium became our first fertilizers. Itwas then that the element calcium and thepractice of liming were put into the back-ground. Unfortunately for the wider appre-ciation of calcium, this element in the formof gypsum was regularly a large part of theacid phosphate that was applied extensivelyin fertilizer to deliver phosphorus. Strangeas it may seem, superphosphate fertilizercarries more calcium than it does phosphorus,and consequently calcium has been used soanonymously or incidentally that its services

have not been appreciated. Fertilizers haveheld our thought. Calcium was an un-noticed concomitant. It has been doingmuch for which the other parts of the fer-tilizers were getting credit. Appreciationof the true significance of calcium in plantnutrition was therefore long delayed.

More recently soil acidity has held atten-tion. This again has kept calcium out ofthe picture. Credit for the service of liminghas been going to the carbonates with whichcalcium is associated in limestone. It wasa case of the common fallacy in reasoning,namely the ascribing of causal significanceto contemporaneous behaviors. Here is theline of reasoning: "Limestone put on thesoil lessens the acidity, and limestone put onthe soil grows clover. Therefore the changein acidity must be the cause of the growingclover." At the same time, there was dis-regarded the other possible deduction,namely: "Limestone put on the soil appliesthe plant nutrient calcium. Therefore theapplied calcium must be the cause of thegrowth of clover."

The labeling of calcium as fertilizer elementof first importance was delayed because scien-tists, like other boys, enjoyed playing withtheir toys. The advent of electrical instru-ments for measuring the hydrogen ion con-centration gave tools and inducement tomeasure soil acidity everywhere. The pHvalues were determined on slight provoca-tions and causal significance widely ascribedto them, when as a matter of fact the degreeof acidity like temperature is a condition andnot a cause of many soil chemical reactions.Because this blind alley of soil acidity wasaccepted as a thoroughfare so long andbecause no simple instrument for measuringcalcium ionization was available, ii has takenextensive plant studies to demonstrate thehidden calcium hungers in plants responsiblein turn for hidden but more extensive hungersin animals. Fortunately, a truce has re-cently been declared in the fight on soilacidity. What was once considered a malady

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CALCIUM 5

is now considered a beneficial condition ofthe soil. Instead of a bane, soil acidity is ablessing in that many plant nutrients appliedto such soil arc made more serviceable by itspresence, and soil acidity is an index of howseriously our attention must go to the de-clining soil fertility.

Now we face new concepts of the mecha-nisms of plant nutrition. By means ofstudies using only the colloidal, or finer, clayfraction of the soil, it was learned that thissoil portion is really an acid. It is alsohighy buffered or takes on hydrogen, cal-cium, magnesium, and any other cations inrelatively large quantities to put them out ofsolution and out of extensive ionic activities.It demonstrated that because of its insolu-bility, it can hide away many plant nutrientsso that pure water will not remove them, yetsalt solutions will exchange with them.This absorption and exchange activity of clayis the basic principle that serves in plant nu-trition. This concept comes as a by-productof the studies of calcium in relation to soilacidity.

Imagine that a soil consists of some cal-cium-bearing minerals of silt size mixed withacid clays. The calcium-bearing mineralinteracts with the hydrogen of the acid clay.The hydrogen goes to the mineral in ex-change for the calcium going to the clay.Imagine further that the plant root enters in-to this clay and mineral mixture. It doesso more readily because of the presenceof the clay. It excretes carbon dioxide(possibly other compounds) into this moistmixture to give-carbonic acid with its ionizedhydrogen to carry on between the root acidand the clay particle and the mineral. Thehydrogen from the root exchanges with thecalcium absorbed on the clay in close contact.

Thus plant nutrition is a trading businessbetween root and mineral with the clay serv-ing as the jobber, or the "go-between."The clay takes the hydrogen offered by theroot, trades it to the silt minerals for thecalcium and then passes the calcium to the

root. Thus nutrients, like calcium, andother positive ions as well, pass from theminerals to the clay and to the root, whilehydogen or acidity, is passing in the oppo-site direction to weather out of the soil itsnutrient mineral reserve and leave finallythe acid clay mixed with unweatherablequartz sand. Acid soils are, then, merelythe indication of nutrient depletion.

V

Calcium plays more than the role of movingonly itself into the plant. This element isserving, apparently, in the mechanism ofmoving other nutrients into the plant (andpossibly excluding some non - nutrients).Careful studies of plants growing on colloidalclay have shown that no growth is possibleunless calcium is moved into the crop. Asthe supply of calcium becomes lower, thecrop may be growing but losing back to thesoil some of the potassium, some of the nitro-gen, some of the phosphorus, and even someof the magnesium planted in the seed whiletaking none of these nutrients from the soil.Unless the calcium is serving its function inthe plant, the crop may be growing and con-tain in both the top and the root less nitro-gen, potassium, and phosphorus than was inthe planted seed.

Here is an unappreciated service by cal-cium. Calcium is associated with moredelivery of phosphorus to the crop when aphosphorus application on limed land, forexample, puts three times as much of thephosphorus into the crop as when phosphatefertilizer is put on without lime. It is asso-ciated with the more effective movement ofnitrogen from the soil into the crop. Itplays some role, possibly in the mechanismof the root membrane through which phos-phosphorus.goes more efficiently perhaps asa calcium phosphate than as any other form.Nitrogen may go through more effectivelyas a nitrate. Here are some services by cal-cium of which the details of mechanism willbe fully eludicated only by future researches.

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6

THE LAND

Calcium plays what might be termed theleadership role amongst the nutrient ions notonly as to their entrance into the plantsbut also as to their combination into theproteinaceous compounds Around which cellmultiplication and life itself center. As theprotein concentration of forages rises, thereis also an increase in the calcium concentra-tion. Also there is accumulation of evidencethat with the increase in protein there goesan increase in vitamins. Legumes, the morenutritious of the forages, have long beenknown for their demand for calcium andhigh content of protein. They are also highin other minerals, so that calcium in theplants seems to synthesize the soil-bornenutrients into the organic combinationsthough it does .ot itself appear as part ofthe final products. Potassium, quite unlikecalcium, is more directly effective in the com-pounding of air and water into carbohy-drates, and like calcium does not itself ap-pear in them. Potassium is effective inmaking bulk or tonnage, of forage. Cal-cium is effective in bringing higher concen-tration of proteins, and other nutrients essen-tial, within that bulk. According : as theactive calcium dominates the supplies ofnutrients in the soil, so proteinaccousness,and with it a high content of growth min-erals, characterize the vegetation produced onthe soil. As potassium dominates, there isplenty of plant bulk but its composition ishighly carbonaceous or it is dominantlywoody.

Here is a general principle that is helpfulin understanding the ecological array ofvegetation. According to it, the vegetationis highly proteinaceous and mineral-rich onour prairies in the soil regions of lower rain-fall or those soils retaining a high mineralcontent with calcium prominent. , Contrari-wise, vegetation is mainly wood, or like theforest, on the more leached soils with lowermineral content but with potassium naturallydominant.

This ecological picture served as a stimulusfor some soil studies of the chemical activities

of the potassium and the calcium whenpresent on the clay in different ratios. Prof.C. E. Marshall of the University of Missouri,has designed electrodes and membranes formeasuring the ionic activity of calciuM andpotassium of the soil in the same way as hy-drogen ion activities are measured. Hisdata of what , might be called pK, and pCa inthe same manner as we speak of pH, demon-strate clearly that the ionic activities in amixture of elements are not independent ofeach other as is true in mixtures of gases.Rather they are complimentary in somecombinations, or opposing in others. Con•sidering calcium and potassium in combina-tion, the latter gains ascendency in relativeactivities as the ratios between the calciumand the potassium become narrower. Thusas calcium is more nearly weathered out of thesoil, potassium becomei relatively more ac-tive in moving into the plant. Here is thephysico-chemical soil situation that provokesthe protein-carbohydrate relation which inturn represents the "grow" foods versus"go" food situation so prominently basicin our hidden hungers and the disturbed ani-mal nutrition.

The soil as it is , nourishment to make onekind of plant or another kind, that is,whether the plants are truly nourishment foranimals or are only so much internal packingmaterial, is the real basis for and real helpin understanding the animal distributionwhether wild or domestic, whether lower orhigher. Cattle growing with case and suc-cess is common in Texas, but meets increas-ing difficulties as one goes eastward. Don-keys are "sweethearts of the desert" wheretheir sure-footedness—and sturdy but fineboncs—among rock soils may well be asso-ciated with highly calcareous feeds grown inmore arid regions. Crossbred with thehorse, the resulting hybrid, or mule, is athome farther east in higher rainfalls andon more leached soil areas. But even then,he is found most commonly on the limestonesoils of Missouri, Arkansas, Kentucky, andTennessee. Grown to maturity in these

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CALCIUM 7

areas and then shipped to the cotton South,the mule survives to render labor becausewith no hope for posterity his calciumsupply transported within him in his bonesis not depleted by reproductive demands.Picture further the sheep and goat accordingto their concentration on different geographicareas, and with them to go the increase ofso-called "troubles and bad luck" in raisingthem as they are in the humid, more acid soilregions. The soil fertility, so prominent asthe foundation of animal reproductive per-formances, has not been appreciated. Weneed to sec our most nutritious foods in thoseanimal products connected with the repro-duction of the animal, namely eggs and milk.Reproduction goes forward only on a planeof liberal supplies of soil fertility and istherefore the safety factor in our living andcan be a safety factor in our thinking.

This picture of animal ecology and itsnutritional reasons based on the soil does notpresent itself without calcium playing a prom-inent part in the causal forces. Soil treat-ments that supply calcium in the humid re-gions are readily detected by the animal ifit is given an opportunity to manifest choiceof grazing the herbages on differently treatedareas. Domestication has dulled the in-stinct of wise food choice in some animals,as for example, greediness of the high-producing milk cow brings bloat on herself.This is less common among cows not sohighly domesticated toward intensive milkproduction. Nevertheless, there is stillenough appetite instinct left in the cowwhen she refuses to eat the grass spot whereurine was dropped to bring about unbalancedplant composition by an excessive nitrogenapplication. Her refusal to cat sweet clover,and her preference for bluegrass over whiteclover, are all evidence that the foster motherof the human race is her own nutritionist andknows her carbohydrate-protein ratios for awell balanced diet. She is demonstratingdaily her appreciation of the whole series ofeffects and causes in variable plant composi-tion as they go back through vegetation to

the soil to demonstrate relations between cal-cium and potassium, and other nutrient ionsof the soil. We need to observe our animalsand learn from them. When we accuse themule of stubbornness in his refusal to eat orto drink, the reflection may not be on thisdumb beast as much as on his master, toostubborn to learn from nature.

VIBy means of the biological assay, our ani-

mals are telling us that they can be fedmore efficiently by wise fertilizer treatmentsof the soil. Soil treatment is not merely acase of the plants' service as mineral haulersto carry calcium from the field to the animalfeedbox, but rather, lime, for example, isapplied to make the plant factory much moreefficient in gathering its various nutrientsfrom the soil and still more efficient in syn-thesizing these with carbon, hydrogen, andoxygen from air and water into the extensivelist of complexes and compounds whose serv-ice to growth and good health we arcslowly unravelling. Soil management ismore than a practice guided by economics; itis a responsibility of nourishing microbes,plants, animals, and humans to their bestgrowth and health.

Animal growth studies testify to the im-portance of liming for its help in better ani-nal nutrition. Sheep studies and rabbit feed-ing trials using Missouri soils with variousforages point clearly to the more efficientconversion of roughages into meat when limewas used as a soil treatment. Increases ashigh as 5o per cent in animal growth from thesame amount of feed consumed are efficienciesthat surely cannot be disregarded when foodis to win the war and protein is the particularfood deficiency. In terms of productionwith reduced labor, the better feeding ofanimals by means of soil treatments surelymust not be neglected when the same acrewith a :onstant labor input can deliver somuch more as food products in the form ofmeat.

Improved products from animals come in

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8 THE LAND

for greater efficiency also by way of lime andfertilizer used on the soil. The wool of thesheep was improved when fed hay grown onsoil given lime and phosphate over thatgrown where only phosphate was used.Fatty secretions were visibly different butquality differences in the fiber were revealedon scouring the wool. Milk, another ani-mal secretion, so commonly considered ofconstant nutrient value has permitted ricketsin the calf, irrespective of ample green feedand ample sunshine for both mother and calfon soils deficient in lime.

Animals and their products have been asafety factor in man's diet in that animals areadditional helps in collecting from widerrange all possible helps toward the food manneeds. Historic man's survivals have pos-sibly been more largely the result of his herdsand flocks than we are wont to believe.But even with the help of animals the soilsmay still be so deficient that animal productsfail to give the full service commonlycredited to them. As we push meat andanimal products out of their more commonplace in our diet, and as we go more nearlyto strictly vegetarianism, the attention to thesoil is all the more important. Man darescarcely circumvent the animal in the bioticpyramid suggested by Aldo Leopold thatincludes soil, microbes, plants, animals, andman in that order from the bottom upward.He may claim vegetarianism, in that he sur-vives without consuming meat, but seldomdoes he exclude milk, cheese, and fish com-pletely and become strictly vegetarian. It istrue that nations, highly vegetarian like theChinese and Japanese, consume mainly rice.It is granted that they are highy vegetarianbut not to the exclusion of the minimum ofsome chicken broth or some fish. This fish re-quired for survival may be only the head ofthis animal as reported by J. B. Powell, thejournalist of Japanese prison experience,

whose refusal to cat even this amount ofanimal products cost him his feet, lost bygangrene, when the companion prisonersas fish head eaters were not so unfortunate.

Current attention to the calcium and otherfertility elements in the soil promises betternutrition and health. Although proper nu-tritional requirements are still very muchthe result of chemico-analytical thinking,we are still discovering more essential partsin the proper diet. We are not yet strictlysynthesizing purely chemical diets. A sig-nificant share of a good diet still consists ofthe so-called "natural" food so that natureis still, for many of us, the best dieticianwhen we prefer to stake our future health onomnivorousness and plenty of natural foodsfrom fertile soils. Synthetic diets will meetthe supreme test, not when they are merelyable to make animals grow or to keep themalive, but rather only when they can carryanimals through their regular reproductivecycles for several generations with numerousand healthy offspring. The natural growthprocesses, initiated and guided in the mainby the chemical nutrients coming from thesoil, are still the main basis of nutrition.Calcium as the foremost clement on the listof the nutrients demanded from the soilhas given us a pattern of the importance ofits role in nutrition. It points with sug-gestions of importance to the other nine ormore elements whose nutritional significancewe do not yet understand as well. Observa-tions and scientific studies under the presentappreciation of our soil as the basis of healthwill soon increase our knowledge of nutritionwhen we recognize the larger principles asthey apply to all the life forms includingmicrobes, plants and animals no less thanman. We shall rapidly come to recognizethat our national health lies in our soil andour future security in soil conservation guidedby nutrition's universal laws.

NOTE: Lee Foundation for Nutritional Research is a non-profit, public service institution,chartered to investigate and disseminate nutritional information. The attached publicationis not literature or labeling for any product, nor shall it be employed as such by anyone.In accordance with the right of freedom of the press guaranteed to the Foundation by theFirst Amendment of the U. S. Constitution, the attached publication is issued and dis-tributed for informational purposes.

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