THE SORGHUMS
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.