The careful application of the principles of soil treatment discussed in the preceding chapters will leave the soil in good condition for sowing, either in the fall or spring. Nevertheless, though proper dry-farming insures a first-class seed-bed, the problem of sowing is one of the most difficult in the successful production of crops without irrigation. This is chiefly due to the difficulty of choosing, under somewhat rainless conditions, a time for sowing that will insure rapid and complete germination and the establishmcnt of a root system capable of producing good plants. In some respects fewer definite, reliable principles can be laid down concerning sowing than any other principle of important application in the practice of dry-farming. The experience of the last fifteen years has taught that the occasional failures to which even good dry-farmers have been subjected have been caused almost wholly by uncontrollable unfavorable conditions prevailing at the time of sowing.
Conditions of germination
Three conditions determine germination: (1) heat, (2) oxygen, and (3) water. Unless these three conditions are all favorable, seeds cannot germinate properly. The first requisite for successful seed germination is a proper degree of heat. For every kind of seed there is a temperature below which germination does not occur; another, above which it does not occur, and another, the best, at which, providing the other factors are favorable, germination will go on most rapidly. The following table, constructed by Goodale, shows the latest, highest, and best germination temperatures for wheat, barley, and corn. Other seeds germinate approximately within the same ranges of temperature:—
Germination Temperatures (Degrees Farenheit)
Lowest Highest BestWheat 41 108 84Barley 41 100 84Corn 49 115 91
Germination occurs within the considerable range between the highest and lowest temperatures of this table, though the rapidity of germination decreases as the temperature recedes from the best. This explains the early spring and late fall germination when the temperature is comparatively low. If the temperature falls below the lowest required for germination, dry seeds are not injured, and even a temperature far below the freezing point of water will not affect seeds unfavorably if they are not too moist. The warmth of the soil, essential to germination, cannot well be controlled by the farmer; and planting must, therefore, be done in seasons when, from past experience, it is probable that the temperature is and will remain in the neighborhood of the best degree for germination. More heat is required to raise the temperature of wet soils; therefore, seeds will generally germinate more slowly in wet than in dry soils, as is illustrated in the rapid germination often observed in well-tilled dry-farm soils. Consequently, it is safer at a low temperature to sow in dry soils than in wet ones. Dark soils absorb heat more rapidly than lighter colored ones, and under the same conditions of temperature germination is therefore more likely to go on rapidly in dark colored soils. Over the dry-farm territory the soils are generally light colored, which would tend to delay germination. The incorporation of organic matter with the soil, which tends to darken the soil, has a slight though important bearing on germination as well as on the general fertility of the soil, and should be made an important dry-farm practice. Meanwhile, the temperature of the soil depends almost wholly upon the prevailing temperature conditions in the district and is not to any material degree under the control of the farmer.
A sufficient supply of oxygen in the soil is indispensable to germination. Oxygen, as is well known, forms about one fifth of the atmosphere and is the active principle in combustion and in tile changes in the animal body occasioned by respiration. Oxygen should be present in the soil air in approximately the proportion in which it is found in the atmosphere. Germination is hindered by a larger or smaller proportion than is found in the atmosphere. The soil must be in such a condition that the air can easily enter or leave the upper soil layer; that is, the soil must be somewhat loose. In order that the seeds may have access to the necessary oxygen, then, sowing should not be done in wet or packed soils, nor should the sowing implements be such as to press the soil too closely around the seeds. Well-fallowed soil is in an ideal condition for admitting oxygen.
If the temperature is right, germination begins by the forcible absorption of water by the seed from the surrounding soil. The force of this absorption is very great, ranging from four hundred to five hundred pounds per square inch, and continues until the seed is completely saturated. The great vigor with which water is thus absorbed from the soil explains how seeds are able to secure the necessary water from the thin water film surrounding the soil grains. The following table, based upon numerous investigations conducted in Germany and in Utah, shows the maximum percentages of water contained by seeds when the absorption is complete. These quantities are reached only when water is easily accessible:—
Percentage of Water contained by Seeds at Saturation
German UtahRye 58 —Wheat 57 52Oats 58 43Barley 56 44Corn 44 57Beans 95 88Lucern 78 67
Germination itself does not go on freely until this maximum saturation has been reached. Therefore, if the moisture in the soil is low, the absorption of water is made difficult and germination is retarded. This shows itself in a decreased percentage of germination. The effect upon germination of the percentage of water in the soil is well shown by some of the Utah experiments, as follows:—
Effect of Varying Amounts of Water on Percentage of Germination
Percent water in soil 7.5 10 12.5 15 17.5 20 22.5 25Wheat in sandy loam 0.0 98 94 86 82 82 82 6Wheat in clay 30 48 84 94 84 82 86 58Beans in sandy loam 0 0 20 46 66 18 8 9Beans in clay 0 0 6 20 22 32 30 36Lucern in Sandy loam 0 18 68 54 54 8 8 9Lucern in clay 8 8 54 48 50 32 15 14
In a sandy soil a small percentage of water will cause better germination than in a clay soil. While different seeds vary in their power to abstract water from soils, yet it seems that for the majority of plants, the best percentage of soil-water for germination purposes is that which is in the neighborhood of the maximum field capacity of soils for water, as explained in Chapter VII. Bogdanoff has estimated that the best amount of water in the soil for germination purposes is about twice the maximum percentage of hygroscopic water. This would not be far from the field-water capacity as described in the preceding chapter.
During the absorption of water, seeds swell considerably, in many cases from two to three times their normal size. This has the very desirable effect of crowding the seed walls against the soil particles and thus, by establishing more points of contact, enabling the seed to absorb moisture with greater facility. As seeds begin to absorb water, heat is also produced. In many cases the temperature surrounding the seeds is increased one degree on the Centigrade scale by the mere process of water absorption. This favors rapid germination. Moreover, the fertility of the soil has a direct influence upon germination. In fertile soils the germination is more rapid and more complete than in infertile soils. Especially active in favoring direct germination are the nitrates. When it is recalled that the constant cultivation and well-kept summer fallow of dry-farming develop large quantities of nitrates in the soil, it will be understood that the methods of dry-farming as already outlined accelerate germination very greatly.
It scareely need be said that the soil of the seed-bed should be fine, mellow, and uniform in physical texture so that the seeds can be planted evenly and in close contact with the soil particles. All the requisite conditions for germination are best met by the conditions prevailing in a well-kept summer fallowed soil.
Time to sow
In the consideration of the time to sow, the first question to be disposed of by the dry-farmer is that of fall as against spring sowing. The small grains occur as fall and spring varieties, and it is vitally important to determine which season, under dry-farm conditions, is the best for sowing.
The advantages of fall sowing are many. As stated, successful germination is favored by the presence of an abundance of fertility, especially of nitrates, in the soil. In summer-fallowed land nitrates are always found in abundance in the fall, ready to stimulate the seed into rapid germination and the young plants into vigorous growth. During the late fall and winter months the nitrates disappear, at least in part, anti from the point of view of fertility the spring is not so desirable as the fall for germination. More important, grain sown in the fall under favorable conditions will establish a good root system which is ready for use and in action in the early spring as soon as the temperature is right and long before the farmer can go out on the ground with his implements. As a result, the crop has the use of the early spring moisture, which under the conditions of spring sowing is evaporated into the air. Where the natural precipitation is light and the amount of water stored in the soil is not large, the gain resulting from the use of the early spring moisture. often decides the question in favor of fall sowing.
The disadvantages of fall sowing are also many. The uncertainty of the fall rains must first be considered. In ordinary practice, seed sown in the fall does not germinate until a rain comes, unless indeed sowing is done immediately after a rain. The fall rains are uncertain as to quantity. In many cases they are so light that they suffice only to start germination and not to complete it and give the plants the proper start. Such incomplete germination frequently causes the total loss of the crop. Even if the stand of the fall crop is satisfactory, there is always the danger of winter-killing to be reckoned with. The real cause of winter-killing is not yet clearly understood, though it seems that repeated thawing and freezing, drying winter winds, accompanied by dry cold or protracted periods of intense cold, destroy the vitality of the seed and young root system. Continuous but moderate cold is not ordinarily very injurious. The liability to winter-killing is, therefore, very much greater wherever the winters are open than in places where the snow covers the ground the larger part of the winter. It is also to be kept in mind that some varieties are very resistant to winter-killing, while others require well-covered winters. Fall sowing is preferable wherever the bulk of the precipitation comes in winter and spring and where the winters are covered for some time with snow and the summers are dry. Under such conditions it is very important that the crop make use of the moisture stored in the soil in the early spring. Wherever the precipitation comes largely in late spring and summer, the arguments in favor of fall sowing are not so strong, and in such localities spring sowing is often more desirable than fall sowing. In the Great Plains district, therefore, spring sowing is usually recommended, though fall-sown crops nearly always, even there, yield the larger crops. In the intermountain states, with wet winters and dry summers, fall sowing has almost wholly replaced spring sowing. In fact, Farrell reports that upon the Nephi (Utah) substation the average of six years shows about twenty bushels of wheat from fall-sown seed as against about thirteen bushels from spring-sown seed. Under the California climate, with wet winters and a winter temperature high enough for plant growth, fall sowing is also a general practice. Wherever the conditions are favorable, fall sowing should be practiced, for it is in harmony with the best principles of water conservation. Even in districts where the precipitation comes chiefly in the summer, it may be found that fall sowing, after all, is preferable.
The right time to sow in the fall can be fixed only with great difficulty, for so much depends upon the climatic conditions. In fact the practice varies in accordance with differences in fall precipitation and early fall frosts. Where numerous fall rains maintain the soil in a fairly moist condition and the temperature is not too low, the problem is comparatively simple. In such districts, for latitudes represented by the dry-farm sections of the United States, a good time for fall planting is ordinarily from the first of September to the middle of October. If sown much earlier in such districts, the growth is likely to be too rank and subject to dangerous injury by frosts, and as suggested by Farrell the very large development of the root system in the fall may cause, the following summer, a dangerously large growth of foliage; that is, the crop may run to straw at the expense of the grain. If sown much later, the chances are that the crop will not possess sufficient vitality to withstand the cold of late fall and winter. In localities where the late summer and the early fall are rainless, it is much more difficult to lay down a definite rule covering the time of fall sowing. The dry-farmers in such places usually sow at any convenient time in the hope that an early rain will start the process of germination and growth. In other cases planting is delayed until the arrival of the first fall rain. This is an certain and usually unsatisfactory practice, since it often happens that the sowing is delayed until too late in the fall for the best results.
In districts of dry late summer and fall, the greatest danger in depending upon the fall rains for germination lies in the fact that the precipitation is often so small that it initiates germination without being sufficient to complete it. This means that when the seed is well started in germination, the moisture gives out. When another slight rain comes a little later, germination is again started and possibly again stopped. In some seasons this may occur several times, to the permanent injury of the crop. Dry-farmers try to provide against this danger by using an unusually large amount of seed, assuming that a certain amount will fail to come up because of the repeated partial germinations. A number of investigators have demonstrated that a seed may start to germinate, then be dried, and again be started to germinate several times in succession without wholly destroying the vitality of the seed.
In these experiments wheat and other seeds were allowed to germinate and dry seven times in succession. With each partial germination the percentage of total germination decreased until at the seventh germination only a few seeds of wheat, barley, and oats retained their power. This, however, is practically the condition in dry-farm districts with rainless summers and falls, where fall seeding is practiced. In such localities little dependence should be placed on the fall rains and greater reliance placed on a method of soil treatment that will insure good germination. For this purpose the summer fallow has been demonstrated to be the most desirable practice. If the soil has been treated according to the principles laid down in earlier chapters, the fallowed land will, in the fall, contain a sufficient amount of moisture to produce complete germination though no rains may fall. Under such conditions the main consideration is to plant the seed so deep that it may draw freely upon the stored soil-moisture. This method makes fall germination sure in districts where the natural precipitation is not to be depended upon.
When sowing is done in the spring, there are few factors to consider. Whenever the temperature is right and the soil has dried out sufficiently so that agricultural implements may be used properly, it is usually safe to begin sowing. The customs which prevail generally with regard to the time of spring sowing may be adopted in dry-farm practices also.
Depth of seeding
The depth to which seed should be planted in the soil is of importance in a system of dry-farming. The reserve materials in seeds are used to produce the first roots and the young plants. No new nutriment beyond that stored in the soil can be obtained by the plant until the leaves are above the ground able to gather Carleton from the atmosphere. The danger of deep planting lies, therefore, in exhausting the reserve materials of the seeds before the plant has been able to push its leaves above the ground. Should this occur, the plant will probably die in the soil. On the other hand, if the seed is not planted deeply enough, it may happen that the roots cannot be sent down far enough to connect with the soil-water reservoir below. Then, the root system will not be strong and deep, but will have to depend for its development upon the surface water, which is always a dangerous practice in dry-farming. The rule as to the depth of seeding is simply: Plant as deeply as is safe. The depth to which seeds may be safely placed depends upon the nature of the soil, its fertility, its physical condition, and the water that it contains. In sandy soils, planting may be deeper than in clay soils, for it requires less energy for a plant to push roots, stems, and leaves through the loose sandy soil than through the more compact clay soil; in a dry soil planting may be deeper than in wet soils; likewise, deep planting is safer in a loose soil than in one firmly compacted; finally, where the moist soil is considerable distance below the surface, deeper planting may be practiced than when the moist soil is near the surface. Countless experiments have been conducted on the subject of depth of seeding. In a few cases, ordinary agricultural seeds planted eight inches deep have come up and produced satisfactory plants. However, the consensus of opinion is that from one to three inches are best in humid districts, but that, everything considered, four inches is the best depth under dry-farm conditions. Under a low natural precipitation, where the methods of dry-farming are practiced, it is always safe to plant deeply, for such a practice will develop and strengthen the root system, which is one big step toward successful dry-farming.
Quantity to sow
Numerous dry-farm failures may be charged wholly to ignorance concerning the quantity of seed to sow. In no other practice has the custom of humid countries been followed more religiously by dry-farmers, and failure has nearly always resulted. The discussions in this volume have brought out the fact that every plant of whatever character requires a large amount of water for its growth. From the first day of its growth to the day of its maturity, large amounts of water are taken from the soil through the plant and evaporated into the air through the leaves. When the large quantities of seed employed in humid countries have been sown on dry lands, the result has usually been an excellent stand early in the season, with a crop splendid in appearance up to early summer. .A luxuriant spring crop reduces, however, the water content of the soil so greatly that when the heat of the summer arrives, there is not sufficient water left in the soil to support the final development and ripening. A thick stand in early spring is no assurance to the dry-farmer of a good harvest. On the contrary, it is usually the field with a thin stand in spring that stands up best through the summer and yields most at the time of harvest. The quantity of seed sown should vary with the soil conditions: the more fertile the soil is, the more seed may be used; the more water in the soil, the more seed may be sown; as the fertility or the water content diminishes, the amount of seed should likewise be diminished. Under dry-farm conditions the fertility is good, but the moisture is low. As a general principle, therefore, light seeding should be practiced on dry-farms, though it should be sufficient to yield a crop that will shade the ground well. If the sowing is done early, in fall or spring, less seed may be used than if the sowing is late, because the early sowing gives a better chance for root development, which results, ordinarily, in more vigorous plants that consume more moisture than the smaller and weaker plants of later sowing. If the winters are mild and well covered with snow, less seed may be used than in districts where severe or open winters cause a certain amount of winter-killing. On a good seed-bed of fallowed soil less seed may be used than where the soil has not been carefully tilled and is somewhat rough and lumpy and unfavorable for complete germination. The yield of any crop is not directly proportional to the amount sown, unless all factors contributing to germination are alike. In the case of wheat and other grains, thin seeding also gives a plant a better chance for stooling, which is Nature's method of adapting the plant to the prevailing moisture and fertility conditions. When plants are crowded, stooling cannot occur to any marked degree, and the crop is rendered helpless in attempts to adapt itself to surrounding conditions.
In general the rule may be laid down that a little more than one half as much seed should be used in dry-farm districts with an annual rainfall of about fifteen inches than is used in humid districts. That is, as against the customary five pecks of wheat used per acre in humid countries about three pecks or even two pecks should be used on dry-farms. Merrill recommends the seeding of oats at the rate of about three pecks per acre; of barley, about three pecks; of rye, two pecks; of alfalfa, six pounds; of corn, two kernels to the hill, and other crops in the same proportion. No invariable rule can be laid down for perfect germination. A small quantity of seed is usually sufficient; but where germination frequently fails in part, more seed must be used. If the stand is too thick at the beginning of the growing season, it must be harrowed out. Naturally, the quantity of seed to be used should be based on the number of kernels as well as on the weight. For instance, since the larger the individual wheat kernels the fewer in a bushel, fewer plants would be produced from a bushel of large than from a bushel of small seed wheat. The size of the seed in determining the amount for sowing is often important and should be determined by some simple method, such as counting the seeds required to fill a small bottle.
Method of sowing
There should really be no need of discussing the method of sowing were it not that even at this day there are farmers in the dry-farm district who sow by broadcasting and insist upon the superiority of this method. The broadcasting of seed has no place in any system of scientific agriculture, least of all in dry-farming, where success depends upon the degree with which all conditions are controlled. In all good dry-farm practice seed should be placed in rows, preferably by means of one of the numerous forms of drill seeders found upon the market. The advantages of the drill are almost self-evident. It permits uniform distribution of the seed, which is indispensable for success on soils that receive limited rainfall. The seed may be placed at an even depth, which is very necessary, especially in fall sowing, where the seed depends for proper germination upon the moisture already stored in the soil. The deep seeding often necessary under dry-farm conditions makes the drill indispensable. Moreover, Hunt has explained that the drill furrows themselves have definite advantages. During the winter the furrows catch the snow, and because of the protection thus rendered, the seed is less likely to be heaved out by repeated freezing and thawing. The drill furrow also protects to a certain extent against the drying action of winds and in that way, though the furrows are small, they aid materially in enabling the young plant to pass through the winter successfully. The rains of fall and spring are accumulated in the furrows and made easily accessible to plants. Moreover, many of the drills have attachments whereby the soil is pressed around the seed and the topsoil afterwards stirred to prevent evaporation. This permits of a much more rapid and complete germination. The drill, the advantages of which were taught two hundred years ago by Jethro Tull, is one of the most valuable implements of modern agriculture. On dry-farms it is indispensable. The dry-farmer should make a careful study of the drills on the market and choose such as comply with the principles of the successful prosecution of dry-farming. Drill culture is the only method of sowing that can be permitted if uniform success is desired.
The care of the crop
Excepting the special treatment for soil-moisture conservation, dry-farm crops should receive the treatment usually given crops growing under humid conditions. The light rains that frequently fall in autumn sometimes form a crust on the top of the soil, which hinders the proper germination and growth of the fall-sown crop. It may be necessary, therefore, for the farmer to go over the land in the fall with a disk or more preferably with a corrugated roller.
Ordinarily, however, after fall sowing there is no further need of treatment until the following spring. The spring treatment is of considerably more importance, for when the warmth of spring and early summer begins to make itself felt, a crust forms over many kinds of dry-farm soils. This is especially true where the soil is of the distinctively arid kind and poor in organic matter. Such a crust should be broken early in order to give the young plants a chance to develop freely. This may be accomplished, as above stated, by the use of a disk, corrugated roller, or ordinary smoothing harrow.
When the young grain is well under way, it may be found to be too thick. If so, the crop may be thinned by going over the field with a good irontooth harrow with the teeth so set as to tear out a portion of the plants. This treatment may enable the remaining plants to mature with the limited amount of moisture in the soil. Paradoxically, if the crop seems to be too thin in the spring, harrowing may also be of service. In such a case the teeth should be slanted backwards and the harrowing done simply for the purpose of stirring the soil without injury to the plant, to conserve the moisture stored in the soil and to accelerate the formation of nitrates.—The conserved moisture and added fertility will strengthen the growth and diminish the water requirements of the plants, and thus yield a larger crop. The iron-tooth harrow is a very useful implement on the dry-farm when the crops are young. After the plants are up so high that the harrow cannot be used on them no special care need be given them, unless indeed they are cultivated crops like corn or potatoes which, of course, as explained in previous chapters, should receive continual cultivation.
Harvesting
The methods of harvesting crops on dry-farms are practically those for farms in humid districts. The one great exception may be the use of the header on the grain farms of the dry-farm sections. The header has now become well-nigh general in its use. Instead of cutting and binding the grain, as in the old method, the heads are simply cut off and piled in large stacks which later are threshed. The high straw which remains is plowed under in the fall and helps to supply the soil with organic matter. The maintenance of dry-farms for over a generation without the addition of manures has been made possible by the organic matter added to the soil in the decay of the high vigorous straw remaining after the header. In fact, the changes occurring in the soil in connection with the decaying of the header stubble appear to have actually increased the available fertility. Hundreds of Utah dry wheat farms during the last ten or twelve years have increased in fertility, or at least in productive power, due undoubtedly to the introduction of the header system of harvesting. This system of harvesting also makes the practice of fallowing much more effective, for it helps maintain the organic matter which is drawn upon by the fallow seasons. The header should be used wherever practicable. The fear has been expressed that the high header straw plowed under will make the soil so loose as to render proper sowing difficult and also, because of the easy circulation of air in the upper soil layers, cause a large loss of soil-moisture. This fear has been found to be groundless, for wherever the header straw has been plowed under; especially in connection with fallowing, the soil has been benefited.
Rapidity and economy in harvesting are vital factors in dry-farming, and new devices are constantly being offered to expedite the work. Of recent years the combined harvester and thresher has come into general use. It is a large header combined with an ordinary threshing machine. The grain is headed and threshed in one operation and the sacks dropped along the path of the machine. The straw is scattered over the field where it belongs.
All in all, the question of sowing, care of crop, and harvesting may be answered by the methods that have been so well developed in countries of abundant rainfall, except as new methods may be required to offset the deficiency in the rainfall which is the determining condition of dry-farming.
The work of the dry-farmer is only half done when the soil has been properly prepared, by deep plowing, cultivation, fallowing, for the planting of the crop. The choice of the crop, its proper seeding, and its correct care and harvesting are as important as rational soil treatment in the successful pursuit of dry-farming. It is true that in general the kinds of crops ordinarily cultivated in humid regions are grown also on arid lands, but varieties especially adapted to the prevailing dry-farm conditions must be used if any certainty of harvest is desired. Plants possess a marvelous power of adaptation to environment, and this power becomes stronger as successive generations of plants are grown under the given conditions. Thus, plants which have been grown for long periods of time in countries of abundant rainfall and characteristic humid climate and soil yield well under such conditions, but usually suffer and die or at best yield scantily if planted in hot rainless countries with deep soils. Yet, such plants, if grown year after year under arid conditions, become accustomed to warmth and dryness and in time will yield perhaps nearly as well or it may be better in their new surroundings. The dry-farmer who looks for large harvests must use every care to secure varieties of crops that through generations of breeding have become adapted to the conditions prevailing on his farm. Home-grown seeds, if grown properly, are therefore of the highest value. In fact, in the districts where dry-farming has been practiced longest the best yielding varieties are, with very few exceptions, those that have been grown for many successive years on the same lands. The comparative newness of the attempts to produce profitable crops in the present dry-farming territory and the consequent absence of home-grown seed has rendered it wise to explore other regions of the world, with similar climatic conditions, but long inhabited, for suitable crop varieties. The United States Department of Agriculture has accomplished much good work in this direction. The breeding of new varieties by scientific methods is also important, though really valuable results cannot be expected for many years to come. When results do come from breeding experiments, they will probably be of the greatest value to the dry-farmer. Meanwhile, it must be acknowledged that at the present, our knowledge of dry-farm crops is extremely limited. Every year will probably bring new additions to the list and great improvements of the crops and varieties now recommended. The progressive dry-farmer should therefore keep in close touch with state and government workers concerning the best varieties to use.
Moreover, while the various sections of the dry-farming territory are alike in receiving a small amount of rainfall, they are widely different in other conditions affecting plant growth, such as soils, winds, average temperature, and character and severity of the winters. Until trials have been made in all these varying localities, it is not safe to make unqualified recommendations of any crop or crop variety. At the present we can only say that for dry-farm purposes we must have plants that will produce the maximum quantity of dry matter with the minimum quantity of water; and that their periods of growth must be the shortest possible. However, enough work has been done to establish some general rules for the guidance of the dry-farmer in the selection of crops. Undoubtedly, we have as yet had only a glimpse of the vast crop possibilities of the dry-farming territory in the United States, as well as in other countries.
Wheat
Wheat is the leading dry-farm crop. Every prospect indicates that it will retain its preŽminence. Not only is it the most generally used cereal, but the world is rapidly learning to depend more and more upon the dry-farming areas of the world for wheat production. In the arid and semiarid regions it is now a commonly accepted doctrine that upon the expensive irrigated lands should be grown fruits, vegetables, sugar beets, and other intensive crops, while wheat, corn, and other grains and even much of the forage should be grown as extensive crops upon the non-irrigated or dry-farm lands. It is to be hoped that the time is near at hand when it will be a rarity to see grain grown upon irrigated soil, providing the climatic conditions permit the raising of more extensive crops.
In view of the present and future greatness of the wheat crop on semiarid lands, it is very important to secure the varieties that will best meet the varying dry-farm conditions. Much has been done to this end, but more needs to be done. Our knowledge of the best wheats is still fragmentary. This is even more true of other dry-farm crops. According to Jardine, the dry-farm wheats grown at present in the United States may be classificd as follows:—
I. Hard spring wheats: (a) Common (b) Durum
II. Winter wheats: (a) Hard wheats (Crimean) (b) Semihard wheats (Intermountain) (c) Soft wheats (Pactfic)
The common varieties of hard _spring wheats _are grown principally in districts where winter wheats have not as yet been successful; that is, in the Dakotas, northwestern Nebraska, and other localities with long winters and periods of alternate thawing and severe freezing. The superior value of winter wheat has been so clearly demonstrated that attempts are being made to develop in every locality winter wheats that can endure the prevailing climatic conditions. Spring wheats are also grown in a scattering way and in small quantities over the whole dry-farm territory. The two most valuable varieties of the common hard spring wheat are Blue Stem and Red Fife, both well-established varieties of excellent milling qualities, grown in immense quantities in the Northeastern corner of the dry-farm territory of the United States and commanding the best prices on the markets of the world. It is notable that Red Fife originated in Russia, the country which has given us so many good dry-farm crops.
The durum wheats or macaroni wheats, as they are often called, are also spring wheats which promise to displace all other spring varieties because of their excellent yields under extreme dry-farm conditions. These wheats, though known for more than a generation through occasional shipments from Russia, Algeria, and Chile, were introduced to the farmers of the United States only in 1900, through the explorations and enthusiastic advocacy of Carleton of the United States Department of Agriculture. Since that time they have been grown in nearly all the dryfarm states and especially in the Great Plains area. Wherever tried they have yielded well, in some cases as much as the old established winter varieties. The extreme hardness of these wheats made it difficult to induce the millers operating mills fitted for grinding softer wheats to accept them for flourmaking purposes. This prejudice has, however, gradually vanished, and to-day the durum wheats are in great demand, especially for blending with the softer wheats and for the making of macaroni. Recently the popularity of the durum wheats among the farmers has been enhanced, owing to the discovery that they are strongly rust resistant.
The _winter wheats, _as has been repeatedly suggested in preceding chapters, are most desirable for dry-farm purposes, wherever they can be grown, and especially in localities where a fair precipitation occurs in the winter and spring. The hard winter wheats are represented mainly by the Crimean group, the chief members of which are Turkey, Kharkow, and Crimean. These wheats also originated in Russia and are said to have been brought to the United States a generation ago by Mennonite colonists. At present these wheats are grown chiefly in the central and southern parts of the Great Plains area and in Canada, though they are rapidly spreading over the intermountain country. These are good milling wheats of high gluten content and yielding abundantly under dry-farm conditions. It is quite clear that these wheats will soon displace the older winter wheats formerly grown on dry-farms. Turkey wheat promises to become the leading dry-farm wheat. The semisoft winter wheats are grown chiefly in the intermountain country. They are represented by a very large number of varieties, all tending toward softness and starchiness. This may in part be due to climatic, soil, and irrigation conditions, but is more likely a result of inherent qualities in the varieties used. They are rapidly being displaced by hard varieties.
The group of soft winter wheats includes numerous varieties grown extensively in the famous wheat districts of California, Oregon, Washington, and northern Idaho. The main varieties are Red Russian and Palouse Blue Stem, in Washington and Idaho, Red Chaff and Foise in Oregon, and Defiance, Little Club, Sonora, and White Australian in California. These are all soft, white, and rather poor in gluten. It is believed that under given climatic, soil, and cultural conditions, all wheat varieties will approach one type, distinctive of the conditions in question, and that the California wheat type is a result of prevailing unchangeable conditions. More researeh is needed, however, before definite principles can be laid down concerning the formation of distinctive wheat types in the various dry-farm sections. Under any condition, a change of seed, keeping improvement always in view, should be baneficial.
Jardine has reminded the dry-farmers of the United States that before the production of wheat on the dry-farms can reach its full possibilities under any acreage, sufficient quantities must be grown of a few varieties to affect the large markets. This is especially important in the intermountain country where no uniformity exists, but the warning should be heeded also by the Pacific coast and Great Plains wheat areas. As soon as the best varieties are found they should displace the miscellaneous collection of wheat varieties now grown. The individual farmer can be a law unto himself no more in wheat growing than in fruit growing, if he desires to reap the largest reward of his efforts. Only by uniformity of kind and quality and large production will any one locality impress itself upon the markets and create a demand. The changes now in progress by the dry-farmers of the United States indicate that this lesson has been taken to heart. The principle is equally important for all countries where dry-farming is practiced.
Other small grains
_Oats _is undoubtedly a coming dry-farm crop. Several varieties have been found which yield well on lands that receive an average annual rainfall of less than fifteen inches. Others will no doubt be discovered or developed as special attention is given to dry-farm oats. Oats occurs as spring and winter varieties, but only one winter variety has as yet found place in the list of dry-farm crops. The leading; spring varieties of oats are the Sixty-Day, Kherson, Burt, and Swedish Select. The one winter variety, which is grown chiefly in Utah, is the Boswell, a black variety originally brought from England about 1901.
_Barley, _like the other common grains, occurs in varieties that grow well on dry-farms. In comparison with wheat very little seareh has been made for dry-farm barleys, and, naturally, the list of tested varieties is very small. Like wheat and oats, barley occurs in spring and winter varieties, but as in the case of oats only one winter variety has as yet found its way into the approved list of dry-farm crops. The best dry-farm spring barleys are those belonging to the beardless and hull-less types, though the more common varieties also yield well, especially the six-rowed beardless barley. The winter variety is the Tennessee Winter, which is already well distributed over the Great Plains district.
_Rye _is one of the surest dry-farm crops. It yields good crops of straw and grain, both of which are valuable stock foods. In fact, the great power of rye to survive and grow luxuriantly under the most trying dry-farm conditions is the chief objection to it. Once started, it is hard to eradicate. Properly cultivated and used either as a stock feed or as green manure, it is very valuable. Rye occurs as both spring and winter varieties. The winter varieties are usually most satisfactory.
Carleton has recommended _emmer _as a crop peculiarly adapted to semiarid conditions. Emmer is a species of wheat to the berries of which the chaff adheres very closely. It is highly prized as a stock feed. In Russia and Germany it is grown in very large quantities. It is especially adapted to arid and semiarid conditions, but will probably thrive best where the winters are dry and summers wet. It exists as spring and winter varieties. is with the other small grains, the success of emmer will depend largely upon the satisfactory development of winter varieties.
Corn
Of all crops yet tried on dry-farms, corn is perhaps the most uniformly successful under extreme dry conditions. If the soil treatment and planting have been right, the failures that have been reported may invariably be traced to the use of seed which had not been acclimated. The American Indians grow corn which is excellent for dry-farm purposes; many of the western farmers have likewise produced strains that use the minimum of moisture, and, moreover, corn brought from humid sections adapts itself to arid conditions in a very few years. Escobar reports a native corn grown in Mexico with low stalks and small ears that well endures desert conditions. In extremely dry years corn does not always produce a profitable crop of seed, but the crop as a whole, for forage purposes, seldom fails to pay expenses and leave a margin for profit. In wetter years there is a corresponding increase of the corn crop. The dryfarming territory does not yet realize the value of corn as a dry-farm crop. The known facts concerning corn make it safe to predict, however, that its dry farm acreage will increase rapidly, and that in time it will crowd the wheat crop for preŽminence.
Sorghums
Among dry-farm crops not popularly known are the sorghums, which promise to become excellent yielders under arid conditions. The sorghums are supposed to have come grown the tropical sections of the globe, but they are now scattered over the earth in all climes. The sorghums have been known in the United States for over half a century, but it was only when dry-farming began to develop so tremendously that the drouth-resisting power of the sorghums was recalled. According to Ball, the sorghums fall into the following classes:—
1. Broom corns 2. Sorgas or sweet sorghums 3. Kafirs 4. Durras
The broom corns are grown only for their brush, and are not considered in dry-farming; the sorgas for forage and sirups, and are especially adapted for irrigation or humid conditions, though they are said to endure dry-farm conditions better than corn. The Kafirs are dry-farm crops and are grown for grain and forage. This group includes Red Kafir, White Kafir, Black-hulled White Kafir, and White Milo, all of which are valuable for dry-farming. The Durras are grown almost exclusively for seed and include Jerusalem corn, Brown Durra, and Milo. The work of Ball has made Milo one of the most important dry-farm crops. As improved, the crop is from four to four and a half feet high, with mostly erect heads, carrying a large quantity of seeds. Milo is already a staple crop in parts of Texas, Oklahoma, Kansas, and New Mexico. It has further been shown to be adapted to conditions in the Dakotas, Nebraska, Colorado, Arizona, Utah, and Idaho. It will probably be found, in some varietal form, valuable over the whole dry-farm territory where the altitude is not too high and the average temperature not too low.
It has yielded an average of forty bushels of seed to the acre.
Lucern or alfalfa
Next to human intelligence and industry, alfalfa has probably been the chief factor in the development of the irrigated West. It has made possible a rational system of agriculture, with the live-stock industry and the maintenance of soil fertility as the central considerations. Alfalfa is now being recognized as a desirable crop in humid as well as in irrigated sections, and it is probable that alfalfa will soon become the chief hay crop of the United States. Originally, lucern came from the hot dry countries of Asia, where it supplied feed to the animals of the first historical peoples. Moreover, its long; tap roots, penetrating sometimes forty or fifty feet into the ground, suggest that lucern may make ready use of deeply stored soil-moisture. On these considerations, alone, lucern should prove itself a crop well suited for dry-farming. In fact, it has been demonstrated that where conditions are favorable, lucern may be made to yield profitable crops under a rainfall between twelve and fifteen inches. Alfalfa prefers calcareous loamy soils; sandy and heavy clay soils are not so well adapted for successful alfalfa production. Under dry-farm conditions the utmost care must be used to prevent too thick seeding. The vast majority of alfalfa failures on dry-farms have resulted from an insufficient supply of moisture for the thickly planted crop. The alfalfa field does not attain its maturity until after the second year, and a crop which looks just right the second year will probably be much too thick the third and fourth years. From four to six pounds of seed per acre are usually ample. Another main cause of failure is the common idea that the lucern field needs little or no cultivation, when, in fact, the alfalfa field should receive as careful soil treatment as the wheat field. Heavy, thorough disking in spring or fall, or both, is advisable, for it leaves the topsoil in a condition to prevent evaporation and admit air. In Asiatic and North African countries, lucern is frequently cultivated between rows throughout the hot season. This has been tried by Brand in this country and with very good results. Since the crop should always be sown with a drill, it is comparatively easy to regulate the distance between the rows so that cultivating implements may be used. If thin seeding and thorough soil stirring are practiced, lucern usually grows well, and with such treatment should become one of the great dry-farm crops. The yield of hay is not large, but sufficient to leave a comfortable margin of profit. Many farmers find it more profitable to grow dry-farm lucern for seed. In good years from fifty to one hundred and fifty dollars may be taken from an acre of lucern seed. However, at the present, the principles of lucern seed production are not well established, and the seed crop is uncertain.
Alfalfa is a leguminous crop and gathers nitrogen from the air. It is therefore a good fertilizer. The question of soil fertility will become more important with the passing of the years, and the value of lucern as a land improver will then be more evident than it is to-day.
Other leguminous crops
The group of leguminous or pod-bearing crops is of great importance; first, because it is rich in nitrogenous substances which are valuable animal foods, and, secondly, because it has the power of gathering nitrogen from the air, which can be used for maintaining the fertility of the soil. Dry-farming will not be a wholly safe practice of agriculture until suitable leguminous crops are found and made part of the crop system. It is notable that over the whole of the dry-farm territory of this and other countries wild leguminous plants flourish. That is, nitrogen-gathering plants are at work on the deserts. The farmer upsets this natural order of things by cropping the land with wheat and wheat only, so long as the land will produce profitably. The leguminous plants native to dry-farm areas have not as yet been subjected to extensive economic study, and in truth very little is known concerning leguminous plants adapted to dry-farming.
In California, Colorado, and other dry-farm states the field pea has been grown with great profit. Indeed it has been found much more profitable than wheat production. The field bean, likewise, has been grown successfully under dry-farm conditions, under a great variety of climates. In Mexico and other southern climates, the native population produce large quantities of beans upon their dry lands.
Shaw suggests that sanfoin, long famous for its service to European agriculture, may be found to be a profitable dry-farm crop, and that sand vetch promises to become an excellent dry-farm crop. It is very likely, however, that many of the leguminous crops which have been developed under conditions of abundant rainfall will be valueless on dry-farm lands. Every year will furnish new and more complete information on this subject. Leguminous plants will surely become important members of the association of dry-farm crops.
Trees and shrubs
So far, trees cannot be said to be dry-farm crops, though facts are on record that indicate that by the application of correct dry-farm principles trees may be made to grow and yield profitably on dry-farm lands. Of course, it is a well-known fact that native trees of various kinds are occasionally found growing on the deserts, where the rainfall is very light and the soil has been given no care. Examples of such vegetation are the native cedars found throughout the Great Basin region and the mesquite tree in Arizona and the Southwest. Few farmers in the arid region have as yet undertaken tree culture without the aid of irrigation.
At least one peach orchard is known in Utah which grows under a rainfall of about fifteen inches without irrigation and produces regularly a small crop of most delicious fruit. Parsons describes his Colorado dry-farm orchard in which, under a rainfall of almost fourteen inches, he grows, with great profit, cherries, plums, and apples. A number of prospering young orchards are growing without irrigation in the Great Plains area. Mason discovered a few years ago two olive orchards in Arizona and the Colorado desert which, planted about fourteen years previously, were thriving under an annual rainfall of eight and a half and four and a half inches, respectively. These olive orchards had been set out under canals which later failed. Such attested facts lead to the thought that trees may yet take their place as dry-farm crops. This hope is strengthened when it is recalled that the great nations of antiquity, living in countries of low rainfall, grew profitably and without irrigation many valuable trees, some of which are still cultivated in those countries. The olive industry, for example, is even now being successfully developed by modern methods in Asiatic and African sections, where the average annual rainfall is under ten inches. Since 1881, under French management, the dry-farm olive trees around Tunis have increased from 45,000 to 400,000 individuals. Mason and also Aaronsohn suggest as trees that do well in the arid parts of the old world the so-called "Chinese date" or JuJube tree, the sycamore fig, and the Carob tree, which yields the "St. John's Bread" so dear to childhood.
Of this last tree, Aaronsolm says that twenty trees to the acre, under a rainfall of twelve inches, will produce 8000 pounds of fruit containing 40 per cent of sugar and 7 to 8 per cent of protein. This surpasses the best harvest of alfalfa. Kearnley, who has made a special study of dry-land olive culture in northern Africa, states that in his belief a large variety of fruit trees may be found which will do well under arid and semiarid conditions, and may even yield more profit than the grains.
It is also said that many shade and ornamental and other useful plants can be grown on dry-farms; as, for instance, locust, elm, black walnut, silverpoplar, catalpa, live oak, black oak, yellow pine, red spruce, Douglas fir, and cedar.
The secret of success in tree growing on dry-farms seems to lie, first, in planting a few trees per acre,—the distance apart should be twice the ordinary distance,—and, secondly, in applying vigorously and unceasingly the established principles of soil cultivation. In a soil stored deeply with moisture and properly cultivated, most plants will grow. If the soil has not been carefully fallowed before planting, it may be necessary to water the young trees slightly during the first two seasons.
Small fruits have been tried on many farms with great success. Plums, currants, and gooseberries have all been successful. Grapes grow and yield well in many dry-farm districts, especially along the warm foothills of the Great Basin. Tree growing on dry-farm lands is not yet well established and, therefore, should be undertaken with great care. Varieties accustomed to the climatic environment should be chosen, and the principles outlined in the preceding pages should be carefully used.
Potatoes
In recent years, potatoes have become one of the best dry-farm crops. Almost wherever tried on lands under a rainfall of twelve inches or more potatoes have given comparatively large yields. To-day, the growing of dry-farm potatoes is becoming an important industry. The principles of light seeding and thorough cultivation are indispensable for success. Potatoes are well adapted for use in rotations, where summer fallowing is not thought desirable. Macdonald enumerates the following as the best varieties at present used on dry-farms: Ohio, Mammoth, Pearl, Rural New Yorker, and Burbank.
Miscellaneous
A further list of dry-farm crops would include representatives of nearly all economic plants, most of them tried in small quantity in various localities. Sugar beets, vegetables, bulbous plants, etc., have all been grown without irrigation under dry-farm conditions. Some of these will no doubt be found to be profitable and will then be brought into the commercial scheme of dry-farming.
Meanwhile, the crop problems of dry-farming demand that much careful work be done in the immediate future by the agencies having such work in charge. The best varieties of crops already in profitable use need to be determined. More new plants from all parts of the world need to be brought to this new dry-farm territory and tried out. Many of the native plants need examination with a view to their economic use. For instance, the sego lily bulbs, upon which the Utah pioneers subsisted for several seasons of famine, may possibly be made a cultivated crop. Finally, it remains to be said that it is doubtful wisdom to attempt to grow the more intensive crops on dry-farms. Irrigation and dry-farming will always go together. They are supplementary systems of agriculture in arid and semiarid regions. On the irrigated lands should be grown the crops that require much labor per acre and that in return yield largely per acre. New crops and varieties should besought for the irrigated farms. On the dry-farms should be grown the crops that can be handled in a large way and at a small cost per acre, and that yield only moderate acre returns. By such cooperation between irrigation and dry-farming will the regions of the world with a scanty rainfall become the healthiest, wealthiest, happiest, and most populous on earth.