DRY-FARMING: A SYSTEM OF AGRICULTURE FOR COUNTRIES UNDER A LOW RAINFALL TEXT

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. CHAPTER XII CROPS FOR 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