CHAPTER XIII
THE COMPOSITION OF DRY-FARM CROPS


THE acre-yields of crops on dry-farms, even underthe most favorable methods of culture, are likely to be much smaller than in humidsections with fertile soils. The necessity for frequent fallowing or resting periodsover a large portion of the dry-farm territory further decreases the average annualyield. It does not follow from this condition that dry-farming is less profitablethan humid- or irrigation-farming, for it has been fully demonstrated that the profiton the investment is as high under proper dry-farming as under any other similargenerally adopted system of farming in any part of the world. Yet the practice ofdry-farming would appear to be, and indeed would be, much more desirable could thecrop yield be increased. The discovery of any condition which will offset the smallannual yields is, therefore, of the highest importance to the advancement of dry-farming.The recognition of the superior quality of practically all crops grown without irrigationunder a limited rainfall has done much to stimulate faith in the great profitablenessof dry-farming. As the varying nature of the materials used by man for food, clothing,and shelter has become more clearly understood, more attention has been given tothe valuation of commercial products on the basis of quality as well as of quantity.Sugar beets, for instance, are bought by the sugar factories under a guarantee ofa minimum sugar content; and many factories of Europe vary the price paid accordingto the sugar contained by the beets. The millers, especially in certain parts ofthe country where wheat has deteriorated, distinguish carefully between the flour-producingqualities of wheats from various sections and fix the price accordingly. Even inthe household, information concerning the real nutritive value of various foods isbeing sought eagerly, and foods let down to possess the highest value in the maintenanceof life are displacing, even at a higher cost, the inferior products. The qualityvaluation is, in fact, being extended as rapidly as the growth of knowledge willpermit to the chief food materials of commerce. As this practice becomes fixed thedry-farmer will be able to command the best market prices for his products, for itis undoubtedly true that from the point of view of quality, dry-farm food productsmay be placed safely in competition with any farm products on the markets of theworld.


Proportion of plant parts

It need hardly be said, after the discussionsin the preceding chapters, that the nature of plant growth is deeply modified bythe arid conditions prevailing in dry-farming. This shows itself first in the proportionof the various plant parts, such as roots, stems, leaves, and seeds. The root systemsof dry-farm crops are generally greatly developed, and it is a common observationthat in adverse seasons the plants that possess the largest and most vigorous rootsendure best the drouth and burning heat. The first function of the leaves is to gathermaterials for the building and strengthening of the roots, and only after this hasbeen done do the stems lengthen and the leaves thicken. Usually, the short seasonis largely gone before the stem and leaf growth begins, and, consequently, a somewhatdwarfed appearance is characteristic of dry-farm crops. The size of sugar beets,potato tubers, and such underground parts depends upon the available water and foodsupply when the plant has established a satisfactory root and leaf system. If thewater and food are scarce, a thin beet results; if abundant, a well-filled beet mayresult.

Dry-farming is characterized by a somewhat shortseason. Even if good growing weather prevails, the decrease of water in the soilhas the effect of hastening maturity. The formation of flowers and seed begins, therefore,earlier and is completed more quickly under arid than under humid conditions. Moreover,and resulting probably from the greater abundance of materials stored in the rootsystem, the proportion of heads to leaves and stems is highest in dry-farm crops.In fact, it is a general law that the proportion of heads to straw in grain cropsincreases as the water supply decreases. This is shown very well even under humidor irrigation conditions when different seasons or different applications of irrigationwater are compared. For instance, Hall quotes from the Rothamsted experiments tothe effect that in 1879, which was a wet year (41 inches), the wheat crop yielded38 pounds of grain for every 100 pounds of straw; whereas, in 1893, which was a dryyear (23 inches), the wheat crop yielded 95 pounds of grain to every 100 pounds ofstraw. The Utah station likewise has established the same law under arid conditions.In one series of experiments it was shown as an average of three years' trial thata field which had received 22.5 inches of irrigation water produced a wheat cropthat gave 67 pounds of grain to every 100 pounds of straw; while another field whichreceived only 7.5 inches of irrigation water produced a crop that gave 100 poundsof grain for every 100 pounds of straw. Since wheat is grown essentially for thegrain, such a variation is of tremendous importance. The amount of available wateraffects every part of the plant. Thus, as an illustration, Carleton states that theper cent of meat in oats grown in Wisconsin under humid conditions was 67.24, whilein North Dakota, Kansas, and Montana, under arid and semiarid conditions, it was71.51. Similar variations of plant parts may be observed as a direct result of varyingthe amount of available water. In general then, it may be said that the roots ofdry-farm crops are well developed; the parts above ground somewhat dwarfed; the proportionof seed to straw high, and the proportion of meat or nutritive materials in the plantparts likewise high.


The water in dry-farm crops

One of the constant constituents of all plantsand plant parts is water. Hay, flour, and starch contain comparatively large quantitiesof water, which can be removed only by heat. The water in green plants is often verylarge. In young lucern, for instance, it reaches 85 per cent, and in young peas nearly90 per cent, or more than is found in good cow's milk. The water so held by plantshas no nutritive value above ordinary water. It is, therefore, profitable for theconsumer to buy dry foods. In this particular, again, dry-farm crops have a distinctadvantage: During growth there is not perhaps a great difference in the water contentof plants, due to climatic differences, but after harvest the drying-out processgoes on much more completely in dry-farm than in humid districts. Hay, cured in humidregions, often contains from 12 to 20 per cent of water; in arid climates it containsas little as 5 per cent and seldom more than 12 per cent. The drier hay is naturallymore valuable pound for pound than the moister hay, and a difference in price, basedupon the difference in water content, is already being felt in certain sections ofthe West.

The moisture content of dry-farm wheat, the chiefdry-farm crop, is even more important. According to Wiley the average water contentof wheat for the United States is 10.62 per cent, ranging from 15 to 7 per cent.Stewart and Greaves examined a large number of wheats grown on the dry-farms of Utahand found that the average per cent of water in the common bread varieties was 8.46and in the durum varieties 8.89. This means that the Utah dry-farm wheats transportedto ordinary humid conditions would take up enough water from the air to increasetheir weight one fortieth, or 2.2 per cent, before they reached the average watercontent of American wheats. In other words, 1,000,000 bushels of Utah dry-farm wheatcontain as much nutritive matter as 1,025,000 bushels of wheat grown and kept underhumid conditions. This difference should be and now is recognized in the prices paid.In fact, shrewd dealers, acquainted with the dryness of dry-farm wheat, have forsome years bought wheat from the dry-farms at a slightly increased price, and trustedto the increase in weight due to water absorption in more humid climates for theirprofits. The time should be near at hand when grains and similar products shouldbe purchased upon the basis of a moisture test.

While it is undoubtedly true that dry-farm cropsare naturally drier than those of humid countries, yet it must also be kept in mindthat the driest dry-farm crops are always obtained where the summers are hot andrainless. In sections where the precipitation comes chiefly in the spring and summerthe difference would not be so great. Therefore, the crops raised on the Great Plainswould not be so dry as those raised in California or in the Great Basin. Yet, whereverthe annual rainfall is so small as to establish dry-farm conditions, whether it comesin the winter or summer, the cured crops are drier than those produced under conditionsof a much higher rainfall, and dry farmers should insist that, so far as possiblein the future, sales be based on dry matter.


The nutritive substances in crops

The dry matter of all plants and plant partsconsists of three very distinct classes of substances: First, ash or the mineralconstituents. Ash is used by the body in building bones and in supplying the bloodwith compounds essential to the various life processes. Second, protein or the substancescontaining the element nitrogen. Protein is used by the body in making blood, muscle,tendons, hair, and nails, and under certain conditions it is burned within the bodyfor the production of heat. Protein is perhaps the most important food constituent.Third, non-nitrogenous substances, including fats, woody fiber, and nitrogen-freeextract, a name given to the group of sugars, starehes, and related substances. Thesesubstances are used by the body in the production of fat, and are also burned forthe production of heat. Of these valuable food constituents protein is probably themost important, first, because it forms the most important tissues of the body and,secondly, because it is less abundant than the fats, starches, and sugars. Indeed,plants rich in protein nearly always command the highest prices.

The composition of any class of plants variesconsiderably in different localities and in different seasons. This may be due tothe nature of the soil, or to the fertilizer applied, though variations in plantcomposition resulting from soil conditions are comparatively small. The greater variationsare almost wholly the result of varying climate and water supply. As far as it isnow known the strongest single factor in changing the composition of plants is theamount of water available to the growing plant.


Variations due to varying water supply

The Utah station has conducted numerous experimentsupon the effect of water upon plant composition. The method in every case has beento apply different amounts of water throughout the growing season on contiguous platsof uniform land. [Lengthy table deleated from this edition.] Even a casual studyof . . . [the results show] that the quantity of water used influenced the compositionof the plant parts. The ash and the fiber do not appear to be greatly influenced,but the other constituents vary with considerable regularity with the variationsin the amount of irrigation water. The protein shows the greatest variation. As theirrigation water is increased, the percentage of protein decreases. In the case ofwheat the variation was over 9 per cent. The percentage of fat and nitrogen-freeextract, on the other hand, becomes larger as the water increases. That is, cropsgrown with little water, as in dry-farming, are rich in the important flesh- andblood-forming substance protein, and comparatively poor in fat, sugar, stareh, andother of the more abundant heat and fat-producing substances. This difference isof tremendous importance in placing dry-farming products on the food markets of theworld. Not only seeds, tubers, and roots show this variation, but the stems and leavesof plants grown with little water are found to contain a higher percentage of proteinthan those grown in more humid climates.

The direct effect of water upon the compositionof plants has been observed by many students. For instance, Mayer, working in Holland,found that, in a soil containing throughout the season 10 per cent of water, oatswas produced containing 10.6 per cent of protein; in soil containing 30 per centof water, the protein percentage was only 5.6 per cent, and in soil containing 70per cent of water, it was only 5.2 per cent. Carleton, in a study of analyses ofthe same varieties of wheat grown in humid and semi-arid districts of the UnitedStates, found that the percentage of protein in wheat from the semiarid area was14.4 per cent as against 11.94 per cent in the wheat from the humid area. The averageprotein content of the wheat of the United States is a little more than 12 per cent;Stewart and Greaves found an average of 16.76 per cent of protein in Utah dry-farmwheats of the common bread varieties and 17.14 per cent in the durum varieties. Theexperiments conducted at Rothamsted, England, as given by Hall, confirm these results.For example, during 1893, a very dry year, barley kernels contained 12.99 per centof protein, while in 1894, a wet, though free-growing year, the barley containedonly 9.81 per cent of protein. Quotations might be multiplied confirming the principlethat crops grown with little water contain much protein and little heat- and fat-producingsubstances.


Climate and composition

The general climate, especially as regards thelength of the growing season and naturally including the water supply, has a strongeffect upon the composition of plants. Carleton observed that the same varietiesof wheat grown at Nephi, Utah, contained 16.61 per cent protein; at Amarillo, Texas,15.25 per cent; and at McPherson, Kansas, a humid station, 13.04 per cent. This variationis undoubtedly due in part to the varying annual precipitation but, also, and inlarge part, to the varying general climatic conditions at the three stations.

An extremely interesting and important experiment,showing the effect of locality upon the composition of wheat kernels, is reportedby LeClerc and Leavitt. Wheat grown in 1905 in Kansas was planted in 1906 in Kansas,California, and Texas In 1907 samples of the seeds grown at these three points wereplanted side by side at each of the three states All the crops from the three localitieswere analyzed separately each year.

The results are striking and convincing. Theoriginal seed grown in Kansas in 1905 contained 16.22 per cent of protein. The 1906crop grown from this seed in Kansas contained 19.13 per cent protein; in California,10.38 percent; and in Texas,12.18 percent. In 1907 the crop harvested in Kansas fromthe 1906 seed from these widely separated places and of very different compositioncontained uniformly somewhat more than 22 per cent of protein; harvested in California,somewhat more than 11 per cent; and harvested in Texas, about 18 per cent. In short,the composition of wheat kernels is independent of the composition of the seed orthe nature of the soil, but depends primarily upon the prevailing climatic conditions,including the water supply. The weight of the wheat per bushel, that is, the averagesize and weight of the wheat kernel, and also the hardness or flinty character ofthe kernels, were strongly affected by the varying climatic conditions. It is generallytrue that dry-farm grain weighs more per bushel than grain grown under humid conditions;hardness usually accompanies a high protein content and is therefore characteristicof dry-farm wheat. These notable lessons teach the futility of bringing in new seedfrom far distant places in the hope that better and larger crops may be secured.The conditions under which growth occurs determine chiefly the nature of the crop.It is a common experience in the West that farmers who do not understand this principlesend to the Middle West for seed corn, with the result that great crops of stalksand leaves with no ears are obtained. The only safe rule for the dry-farmer to followis to use seed which has been grown for many years under dry-farm conditions.


A reason for variation in composition

It is possible to suggest a reason for the highprotein content of dry-farm crops. It is well known that all plants secure most oftheir nitrogen early in the growing period. From the nitrogen, protein is formed,and all young plants are, therefore, very rich in protein. As the plant becomes older,little more protein is added, but more and more carbon is taken from the air to formthe fats, starches, sugars, and other non-nitrogenous substances. Consequently, theproportion or percentage of protein becomes smaller as the plant becomes older. Theimpelling purpose of the plant is to produce seed. Whenever the water supply beginsto give out, or the season shortens in any other way, the plant immediately beginsto ripen. Now, the essential effect of dry-farm conditions is to shorten the season;the comparatively young plants, yet rich in protein, begin to produce seed; and atharvest, seed, and leaves, and stalks are rich in the flesh- and blood-forming elementof plants. In more humid countries plants delay the time of seed production and thusenable the plants to store up more carbon and thus reduce the percent of protein.The short growing season, induced by the shortness of water, is undoubtedly the mainreason for the higher protein content and consequently higher nutritive value ofall dry-farm crops.


Nutritive value of dry-farm hay, straw, and flour

All the parts of dry-farm crops are highly nutritious.This needs to be more clearly understood by the dry-farmers. Dry-farm hay, for instance,because of its high protein content, may be fed with crops not so rich in this element,thereby making a larger profit for the farmer. Dry-farm straw often has the feedingvalue of good hay, as has been demonstrated by analyses and by feeding tests conductedin times of hay scarcity. Especially is the header straw of high feeding value, forit represents the upper and more nutritious ends of the stalks. Dry-farm straw, therefore,should be carefully kept and fed to animals instead of being scattered over the groundor even burned as is too often the case. Only few feeding experiments having in viewthe relative feeding value of dry-farm crops have as yet been made, but the few onrecord agree in showing the superior value of dry-farm crops, whether fed singlyor in combination.

The differences in the chemical composition ofplants and plant products induced by differences in the water-supply and climaticenvironment appear in the manufactured products, such as flour, bran, and shorts.Flour made from Fife wheat grown on the dry-farms of Utah contained practically 16per cent of protein, while flour made from Fife wheat grown in Lorraine and the MiddleWest is reported by the Maine Station as containing from 13.03 to 13.75 per centof protein. Flour made from Blue Stem wheat grown on the Utah dry-farms contained15.52 per cent of protein; from the same variety grown in Maine and in the MiddleWest 11.69 and 11.51 per cent of protein respectively. The moist and dry gluten,the gliadin and the glutenin, all of which make possible the best and most nourishingkinds of bread, are present in largest quantity and best proportion in flours madefrom wheats grown under typical dry-farm conditions. The by-products of the millingprocess, likewise, are rich in nutritive elements.


Future Needs

It has already been pointed out that there isa growing tendency to purchase food materials on the basis of composition. New discoveriesin the domains of plant composition and animal nutrition and the improved methodsof rapid and accurate valuation will accelerate this tendency. Even now, manufacturersof food products print on cartons and in advertising matter quality reasons for thesuperior food values of certain articles. At least one firm produces two parallelsets of its manufactured foods, one for the man who does hard physical labor, andthe other for the brain worker. Quality, as related to the needs of the body, whetherof beast or man, is rapidly becoming the first question in judging any food material.The present era of high prices makes this matter even more important.

In view of this condition and tendency, the factthat dry-farm products are unusually rich in the most valuable nutritive materialsis of tremendous importance to the development of dry-farming. The small averageyields of dry-farm crops do not look so small when it is known that they commandhigher prices per pound in competition with the larger crops of more humid climates.More elaborate investigations should be undertaken to determine the quality of cropsgrown in different dry-farm districts. As far as possible each section, great orsmall, should confine itself to the growing of a variety of each crop yielding welland possessing the highest nutritive value. In that manner each section of the greatdry-farm territory would soon come to stand for some dependable special quality thatwould compel a first-class market. Further, the superior feeding value of dry-farmproducts should be thoroughly advertised among the consumers in order to create ademand on the markets for a quality valuation. A few years of such systematic honestwork would do much to improve the financial basis of dry-farming.