FORAOE FOR ( FLTIYATION ON ALKALI .

By JARED G. SMITH, Assistant Agrostologist.

INTRODUCTION. When the excess of alkali in a rises to such a sum total that the cereals can not be grown, the best use to which the land can be put is the growth of forage. There is no crop, so far as known, which can be profitably grown on land that contains over 2 per cent of the combined alkalies within the first 2 inches of surface soil. Soils containing as much as 1 per cent of alkalies within the first 2 inches will not grow cereals, and the maximum for trees, vines, and root crops is much lower. There are extensive areas in the West which are thus excluded from the cate- gory of farming lands because of the excess of alkalies. Such lands are not necessarily barren, although they can not be profitably culti- vated. They are often covered by a rank growth of vegetation, indi- cating that there is an abundance of food in the soil, if only the plants are so tolerant of alkali as to be able to secure it. Many of the alkaii plants have considerable value as forage, and of these some few show special adaptation to the changed conditions which cultiva- tion brings. The crops which originated in humid regions will not grow on soils which are strongly impregnated with the alkalies, and so to meet the conditions one must either take the useful plants of the alkali regions of his own country or depend upon those which have been introduced from similar regions elsewhere. If it is not possible to grow a vine- yard or an orchard, a field of alfalfa or one of grain, there are a number of forage crops that can be successfully cultivated, because they originated in alkali regions and are tolerant of considerable amounts of alkali in the soil. As the amount of alkali in the soil increases the number of species of plants which will thrive decreases. Hilgard, Loughridge, and Davy have published many interesting observations as to the occur- rence of different plants an alkali soils, and as to the maximum quan- tities of alkali of which different native plants and cultivated crops are tolerant. Davy states that there are in the State of , 197 species that grow only on alkali soils. Some of these occur in similar situations in many other parts of the West, while others are found only in California. The greasewood of the Pacific {Allen- rolfea occidentalis) will grow in a soil containing a maximum of 194,760 535 536 YEARBOOK OF THE DEPARTMENT OF AGRICULTURE. pounds of alkali salts pen* acre to the depth of 1 foot. The scrub saltbush { polijcarpu) will grow where there are 78,240 pounds, while samphire {Salicorniu) Avas found gi'owing on land wiiich con- tained 306,000 pounds, or more than fourteen times as much as the greatest amount of Avhich wheat is tolerant. Wheat will grow on land w^liich contains a total of 20,520 pounds or less of the sulphates, carbonates, chlorides, and nitrates of soda and potash per acre to the depth of 1 foot. This amount of alkalies is less than one-half of 1 per cent by weight of the soil. In contrast, Kentucky blue grass Avill only withstand a total of 2,680 pounds, w^hile Australian salt bush will endure 30,020 pounds.

EFFECT OF ALKALIES ON PLANT GROWTH. When wheat is sown on land containing as much as 1 per cent of the alkalies, the are unable to germinate, or if takes place the young i)lants die of thirst, although the soil may contain w^ater enough for the needs of the plants if the alkalies were eliminated. Alkalies in solution increase the density of the soil waters, and the young plants die of thirst, because the soil absorbs the Avater from their roots instead of the roots absorbing water from the soil. There is usually more alkali at the surface than at the depths where the roots feed, and it is often the case that a crop will live on land containing an amount of alkali which w-ould prevent Che germination of its seeds. Thus alfalfa is an excellent crop for mod- eratelj'^ alkaline soils, because the thick growth and abundant leafage shade the soil and prevent evaporation of water and accumulation of alkalies at the surface. The long penetrate to the deeper levels, where there is comparatively little of the alkali present. When there is an excess of the injurious salts at the surface, the seeds are unable to absorb water and there is marked retardation of germination. Buffum^ has shown that while 82 per cent of alfalfa seeds germinated in five days on soil from wdiich the alkali liad been extracted and in four days on wet pads containing no alkali, it required fourteen days to germinate 80 per cent when 1 per cent of combined alkalies was present. A similar retardation took place with turnips, barley, rye, oats, and wheat. The seeds appear to lie dormant for a short time, ready to start growth w^hen the alkaline solution becomes sufficiently diluted to enable them to take up the necessary water. Similar germination experiments were undertaken by Dr. Leather^ during his investigations of **usar" land in northw^est India in 1895 and 1896 to determine the effect of the soda salts on seeds of corn, wheat, barley, peas, gram, and cotton. The germination of the cereals was seriously affected by seven-tenths per cent of either sal soda or Glauber's salt in the soil. The germination of corn and barley was

»Bui. 29, Wyo. Agr. Exp, Sta., 189G. 2 Agr. Ledg. Ko. 13,1897 (Calcutta). FORAGE PLANTS FOR ALKALI SOILS. 537 retarded by from two-tenths to four-tenths per cent of common salt, and cotton was similarly affected. Peas and chick-peas were affected by a much smaller per cent. Two-tenths per cent of the black alkali prevents the growth of most cultivated crops from the , corroding and destroying the plumule after it has emerged from the seed coats. But where the deeply rooted leguminous crops, such as alfalfa, once become established, or where rooted cuttings of other plants are set out so that the roots feed below the surface, they will withstand more alkali than the cereals or other annuals. The salts are concentrated at the surface, and thus prevent the germination of the seeds, while the alfalfa and the rooted cuttings feed at depths where a very much smaller amount is present.

NATIVE PLANTS OF ALKALI SOILS. Among the plants which only grow on alkali soils, there ai'e many which are valuable for forage. The late Baron Von Mueller, the eminent Australian botanist, first drew attention to the importance of the cultivation of such plants. In the first edition of his work, * ' Select extratropical cultivated plants," published in 1872, he showed the possibility of utilizing the orache, a saltbush of the gardens, which is a native of southern Europe and Africa. In the 3876 edition he added two species of Australian saltbushes to his list. Later ext)lorations, conducted largely by Yon Mueller and associated botanists, developed the fact that the vegetation of extensive areas in the central portion of Australia, notably in western New South AYales, , and South Australia, consisted almost entirely of Atriplex. The fact was known that these Atriplex, or saltbush, areas would carry and main- tain in better condition a larger number of sheep and cattle than would be supposed, judging from the limited grass vegetation. Stock grazed on saltbush was also remarkably free from parasitic diseases, and it was assumed that the plants had tonic properties owing to some bitter principle, together with the large amount of salt, found in the . Through Von Mueller's efforts, the cultivation of a number of saltbushes was undertaken in South Africa and Australia, northwest India, and later in California, and everywhere the plants showed remarkable adaptation to saline or alkali-impregnated soils. The success of these experiments led to similar ones with saltbushes native to the various alkali regions of the world, and a larger number of species have been shown to be adaptable to the various climatic zones. To show the small beginnings of one of these experiments, Mr. E. G.- Alston, the well-known experimental agriculturist of Cape Colony, planted in April, 1886, six seeds of Atriplex haJimoides^ which had been obtained by Professor MacOwan from Baron Von Mueller. Two of the seeds germinated, but one plant died before reaching maturity. The seeds from the single remaining plant were saved and tried the 538 YEARBOOK OF THE DEPARTMENT OF AGRICULTURE. following yoai*s on ¿i larger scale. This one plant lias been the mother of nearly all of the South African stock of a species now widely culti- vated by sheep men in all of the colonies. The seed production of all of the saltbushes is enormous. Plants of Atriplex semÜKWcaia^ grown on the grounds of the Department of Agriculture, commenced to blossom and ripen seed w^hen only G inches high, and continued until their growth was cheeked by severe frosts, about the first of November, It is probable that many of the plants ripen thousands of seeds in a season's growth. A plat of Atriplex holocarpa, 6 feet square, ripened half a bushel of seed, gathered by frequent i^ickings during the season of 1898. On the first of Novem- ber, when growth had entirely ceased, the ground was covered to the depth of 2 inches with the globular, spongy seeds. The saltbush that has been most extensively cultivated in this country is A, semi- baccata, which was introduced by the California experiment -station about 1880. Importations of seeds of-this and others have since been made by the Department of Agriculture and by a number of Western experiment stations. Numerous analyses of the different saltbushes and alkali pbmts have been made with the view of determining their feeding value. The percentage of ash is very high, ranging from as much as 19.1 per cent of the total weight of dry matter of the plant in A. semibaccata to 31.3 in A. nurnmularla, and even 37.2 in Koclda pyramidaki. The alkali grass {Sporobolus airoides), which, as its name implies, thrives on alkali lands, contains but 9 per cent of ash, while the amount in alfalfa averages only 2.7 per cent. The difference in the composition of the ash in a number of these plants is shown by the following table : Composition of tJie ash of saltbtishes and greasewood, compared trith that of Eastern-grown alfalfa and timothy .

6 1 4 o 1 8 Name of x)lant. •i ce tí i i % 1 h i 1 i ai 1 1 1 < S i 1 1 Saltbush, Atriplex semi- P.ct. P.cf. P.ct P,ct. P.ct. p.* P.ct p.ct P.ct P.ct P.ct. P.ct P.ct P.ct baecata ' 1« ?4 11 4? ;î5 W 5 7<» 3.23 1 ÍÍ8 1 m 2.80 2 64 24.33J Saltbush, Atriplex 7ium- i i mularia^ _ 1.12 15.6'j'ií29.57 8.135 6.77 .64 4.11 1 3.17Í ;30.28 Gray bush, Kochia pyra- i \ niidata^ 1 :^9, 12. ;ä) 34.43 8 75 7 îî-' 1 í>>< 3.98^.... 1.11 ':í6.67 Greasewood, Allenrolfea í 1 occidentalis i 11.SI 18.5339.45 1 . ;íf> 1 09 3 51 4.93' .._.'._.. ' Greasewood, Sarcobahis vermiculatus ^ . . 3.00'23.06ia.89 fí.52 1 35 (*) *4 73 A. ^9 4 33 8 01 23 80 Eastern timothy hay * 35.e.aJ28.80! 2.70 9.30 3. CO 10.80 3.90Í 5.00 »Eastern alfalfa hay ^ 9.38 23.45 1.56 44.30 4.68 8.34 H 3.12 1 Bul. 105, CaL Agr. Exp. Sta., 1894. a ßiii. gg, N. Mex. Agr.' Exp. Sta., 1997. 2 Journ. Proc. Roy. Soc. N. S. W., Vol. XIV, 137,1880. * Iron and alumina estimated together. FORAGE PLANTS FOR ALKALI SOILS. 539

The most striking variation is in tlio amount of soda ¡Dresent in the ash of the greasewood and saltbushes as compared with " Eastern alfalfa and Eastern timothy hay. In the latter the amount is incon- siderable, while nearly two-fifths of the ash of greasewood (Allenrol- fea) is composed of soda. The draft on potash and phosphoric acid is very much greater in the alfalfa and timothy than in the salt- bushes. Alfalfa takes up five times as much lime as any one of them. Hilgard has estimated that a crop of 20 tons of green saltbush, equal to 5 tons of saltbush hay, will remove 1 ton of soluble mineral matter from the soil. Where the excess of alkali is only very slightly above the maximum borne by the cereals, the land can be put in condition for the growth of other crops by planting saltbush and removing the successive crops from the field. If a soil containing 30,000 pounds of the soda salts to the acre foot is cropped with saltbush, which is each year removed from the field and fed elsewhere, the time when wheat and barley maj^ be grown will be hastened. Saltbush would not produce this effect if it were allowed to remain on the field or if it were grazed. Neither can this method be profitably used where there is any very large amount of alkali in the surface soil, on account of the time requisite for noticeable improvement. At a 20-ton yield of the green herbage per acre the soda salts removed each year would amount to 1,200 pounds.^ Saltbush withstands black alkali better than any other cul- tivated crop, probably because the dense mat of vegetation completelj" shades the soil and prevents evaporation and the subsequent rise of the salt to the surface^ where it becomes poisonous to plant life.

SALTBUSHES NATIVE TO AUSTRALIA. There are a large number of Australian saltbushes which would be valuable if introduced into this country. There are undoubtedly many which may be profitably experimented with to supply the needs of sections too cold for the successful growth of those already intro- duced. Some of the more valuable will be mentioned here.

AUSTRALIAN SALTBUSH. Australian saltbush {, fig. 125) is a niucli- branched perennial, which forms a thick mat over the gi'ound to the depth of a foot. The branches extend from 6 to 8 or 10 feet, so that one plant will often cover an area of 20 feet in diameter. The leaves are about an inch long, broadest at the apex, and coarsely toothed along the margin. They are fleshy and somewhat mealy on the out- side. The pulpy, flattened fruits are tinged with red at maturity, but dry out as soon as they fall from the plant. They are produced in enormous numbers and ripen continuously for three or four months, or in situations v^^here growth is perennial throughout tlie year. At the California experiment station it was determined that

^Bul. 105, Cal. Agr. Exp. Sta., p. IG, 1894. 540 YEARBOOK OF THE DEPARTMENT OF AGRICULTURE.

the seeds germinate better when sown directly on the surface without any covering. When they were harrowed in to the depth of 2 or 3 inches most of them either rotted before germination or the young seedlings were unable to reach the surface. Some practical stockmen have had good results in establishing this saltbush on an alkali range by sowing the seed on the ground when it was wet with heavy and at once driving a flock of sheep over the land, thus treading them into the soil. Sheep are especially fond of this saltbush, and cattle relish it if combined with other feed. Von Mueller states that in his opinion many of the valuable qualities of the Australian wools are due to the abundance of this and other saltbushes in the regions in which the

FIG. 1:^0.—Australian saltbush (Atriplex semibaccata) grown in the grass garden of the Depart- ment of Agriculture. sheep are grazed, and Turner states that if the saltbushes were entirely exterminated it would tend to decrease the value of the wool. The plant may be propagated by cuttings, as well as from seed, and this method is to be preferred wherever the land contains much alkali. The seeds will germinate in the presence of an amount of soda salts which would entirely prevent the growth of cereals. This is especially true in the case of Glauber's salt, though there is of course a limit to the amount of alkali the plant will tolerate, as in the case of wheat or alfalfa. This saltbush is perennial in California, Arizona, and New Mexico, but must be treated as an annual wher- ever the are at all severe. In South Dakota plants from seed sown in May had just commenced to blossom at the time of the first hard frost in autumn. FORAGE PLANTS FOR ALKALI S01L8. 541

Atriplex semibiiccata is the most promising of the Australian salt- T)ushes for cultivation in this countrv, both because of its hardiness and the bulk of fodder produced. The forage contains 11.6 per cent of crude protein in the air-dr}^ substance as compared with 14.3 per cent for. alfalfa. Thus, 100 pounds of the dry substance will contain 8.7 pounds of digestible crude protein as compared with 10.0 pounds in alfalfa. The nutritive ratio is 1 to 4.5 for saltbush iind 1 to 4.1 for alfalfa, so that it would seem to have nearly as high a feeding value as the latter, assuming that the extraordinarily large ash content does not prove detrimental to the animal.

SLENDER SALTBUSH. Slender saltbush {Afriplex leptocarpa) is a perennial, with procum- bent stems from 1^ to 2 feet or more in length. It resembles the \yve- vious species jn many particulars, though the plants are smaller and it produces a smaller amount of forage. It is more widely distrib- uted in Australia than A. semihaccata^ occurring in western Queens- land and and in South Australia along the Murray River, sometimes carpeting the ground over considerable areas. Von Mueller says that its -enduring qualities are remarkable. It is particularly relished by sheep, which browse it down so closely that large tracts of it are often entirely destroyed. The seeds are smaller than those of A, semihaccata^ somewhat cylindrical in shape, two- pointed at the apex, and slightly swollen at the middle. They are produced in great abundance and germinate readily under ordinary conditions. This species has been tried in California and in the grass garden on the grounds of the Department of Agriculture, and a fair quantity of seed has been distributed to a number of farmers in the West. It is about equally hardy, as regards cold, as A, semibaccata, but will perhaps withstand a greater degree of heat.

GRAY SALT BUSH. Gray saltbush {Atriplex halimoides) is a shrubby perennial with something of the habit of A. semibaccata. The leaves are larger and broader and the whole plant has a whitish appearance. The stems are rather more woody than in the case of either of the two preceding species and the plant is more drought resistant. On this account it has proved adapted to conditions in South Africa and probably also would be of value in South America. When not too closely grazed it ripens seed in great abundance. It would be valuable for trial in Arizona and southern California.

ROUND-LEAFED SALTBUSH. Round-leafed saltbush {) is a perennial shrub which grows to the height of from G to 10 feet. The leaves and stems are covered with whitish down, and the broad, fleshy leaves are 542 YEARBOOK OF THE DEPARTMENT OF AGRICULTURE. produced in great abundance. The i)lant is diœcions, producing male flowers on one plant and female flowers on another. It will grow on soils more heaAÜy impregnated with alkali than A. semihaccata, and will also withstand dronghts better, l)ut is less hardy to cold. It is extensively planted and highly valued in central Australia and South Africa. In habit of growth and appearance it resembles the native shad scale of the Rocky Mountain region. It is only adapted to cul- tivation in the warmest porticms of the Southwest and it might well be grown more extensively in southern California and Arizona, if rooted cuttings are planted over the range immediately following heavy rains, wlien the soil is wet enough to fairly start the plant, it

FIG. 1Ä>.—Anniml saltbusb (Atriplex holocarpa) grown in the grass garden of the Department of Agriculture. will undoubtedly be a very valuable addition to the range fonige plants. This saltbush produces the greatest amount of seed in the driest seasons, resembling in this characteristic most native desert plants. The seeds germinate readily when sown on moist soils. According to analyses the round-leafed saltbush will üike up more soda salts than will A. semibaccata, and on this account will proba- bly succeed on soils too heavily impregnated with alkali to permit the growth of other species. ANNUAL SALTBUSH. Annual saltbush {AfriiHex holocarpa, fig. 126) is a low, densely branching annual, less leafy than either of the pi-eceding species, but FORAGE PLANTS FOR ALKALI SOILS. 543 valuable because of the immense number of round, spongy seeds or fruits which it produces. The fruits are from one-fourth to one-half incli in diameter and are readil}^ blow n about by the wind, so that if the i)lant is once established on the range and is not eaten down too closely by stock it will soon become ^\idely distributed. It is one of the saltbushes which is fairly hard}', but is perhaps less drought resistant than many of the perennials. Tlie seeds are not only carried by the wind, but float on the water, and are widely scattered in this wa}" by floods or by the torrential rains to which the arid regions which it inhabits are subjected. Its successful growth in the grass garden on the grounds of the Department of Agriculture indicates that it would be a valuable species to introduce not only on alkaline soils, but also in the grazing regions of the West and Southwest, prob- ably as far north as Colorado and Utah.

OLD-MAN SALTBUSH. Old-man saltbush {Ehagodia parabólica) is an erect, perennial shrub, formerly very abundant in western Queensland and New South Wales, but which has now almost disappeared because of overgrazing by cattle. »It grows 5 to 10 feet high, frequenting low^ moist places. The whole plant is whitish, with a meaty covering like that on the leaves of the common garden pig's foot or lambVquarters {Clienopo- dium album). Cattle and sheep browse th^e leaves and tender branches, seldom permitting it to ripen seed in any quantity, but it grows well from cuttings and may be rapidly disseminated in that manner.

ARROW-LEAFED SALTBUSH. Arrow-leafed saltbush {Rhagodia liastata) is a low, spreading, per- ennial shrub, seldom growing more than 3 to 5 feet high. Like the preceding, its leaves and branches are whitish. Cattle and sheep graze this plant wherever found. It grows wild in Queensland, New South Wales, and Victoria, and is said to be one of the most drought resistant of all the saltbushes. It will stand some frost, and would be a good plant, to introduce on the cattle ranges of Texas and Xew Mexico. Like all others of this group, it not only produces an abun- dance of seed, but may readily be reproduced from cuttings.

BLUE SALTBUSH. Blue saltbush {Clienopodium auricoviuin)!^ another shrub that was formerly abundant in the hottest portions of the interior of Australia, but has now almost entirely disappeared. The writer collected some of it in 1891 in western New South Wales. It was in a thicket of "wait-a-bit" and other thorny acacias, protected by them from all browsing animals, much as clumps of succulent grasses are often found in cactus thickets in Texas and the Southwest. Blue saltbush is so called from its color, which varies from blue-gray to yellow. It 544 YEARBOOK OF THE DEPARTMENT OF AGRICULTURE. is an excellent forage plant, and its introduction into the arid ranges of the Southwest is recommended. It seeds abundantly, and may also be propagated from cuttings.

GRAY BUSH. Of the gray bush (Kochia) there are a dozen or more species in tlie arid portions of Australia. All are shrubby perennials, more or less sought after by cattle and sheep, and are correspondingly valued by owners of stock. One characteristic feature of all of them is that their leaves and branches are covered with short white woolly hairs, that prevent the evaporation of water from the leaves. They are adapted to the driest and hottest climates, and are without exception alkali plants. Some of the Kochias flourish in central Australia, where the day temperatures approach those of the Death Valley in southern California. They would be valuable for introduction into southern Arizona and the deserts of southern California as range plants, to supplement the forage supplied by Franseria, Allenrolfea, and other shrubs. An objection to the Kochias is that the matted tomentum with which they are covered often forms hair balls or phyto-bezoars in the stomachs of cattle, sometimes causing consider- able losses during . But as similar losses occur from the feeding of overripe crimson clover and a variety of other plants, this objection need not be considered a fatal one. The Kochia saltbushes resemble the fat {Eurotia lanata) and cottonweed (Froelichia) of Texas and the West in appearance, and to some extent also in feed- ing value, although the latter do not approach them in the matter of seed production. AMERICAN SALTBUSHES. A great number of saltbushes may be introduced from Australia for the benefit of the Western stockmen, but while foreign species are being sought, the native saltbushes, which thrive on alkaline and saline soils, should not be overlooked. There are about 40 species of native Atriplex saltbushes in the Western States. Many of these are superior to those of Australia, in that they are hardy as regards cold as well as resistant to alkali and drought. They are grazed to some extent In , but are, as a rule, most highly valued for winter forage, because there is an abundance of nutritious and succulent grasses and annual plants in summer, so that the saltbushes are not then required. SHAD SCALE. Shad scale {, ñg. 127), is a perennial shrub, often 0 to 10 feet high, rather common on the high plains from Wyoming and Nevada to Arizona and western Texas. The narrow gray-green leaves and 3'^OTing branches are browsed by cattle. The seeds are FORAGE PLANTS FOR ALKALI SOILS. 545 produced in great abundance, often a peck or more on one plant. These- are much sought after by sheep and are considered very fattening. On ranges used as summer for sheep the shad scale caTi now only be found on rocky cliifs or other spots inaccessible to grazing: animals; but in regions which can only be pastured in winter through lack of water, except that supplied by snowdrifts, the shad scale is found to be increasing from year to year. This is because the stock are necessarily kept off in summer, so that the plant has opportunity to fully recover from the winter grazing and mature its normal crops of seed. Shad scale grows on lands heavily impregnated with w^hite alkali, and also withstands small amounts of the black alkali. It is worthy of cultivation on soils that will not grow grain, alfalfa, or tame grasses. This plant is superior to the shrubby Aus- tralian saltbushes, in that it thrives where the winters are quite severe.

NUTTALL'S SALT SAGE. Nuttall'ssalt sage {Atnplex 7iutfallii\ fig. 128) is the most common salt sage of the plains of northern Colorado, Wyo- ming, Montana, and northern Nevada, and is considered by stockmen the most valuable of that region. It is a low, leafy shrub, seldom more than 2 or 3 feet high, and, like the shad scale, is peren- FIG. 1:¿7.—Shad scale (Atriplex cancficens)'. o, fruit; />, flower. nial. It grows where the soil is dry and so strongly impregnated Avith alkali that little else will thrive except rabbit brush and bitter sages. It is one of the best of the wild forage plants for winter pasturage. Nelson states that the leaves and young twigs, and especially the seeds, are very fattening, and that sheep eat the forage both green and when it has cured upon the ground. The plant endures much severe trampling and hard usage. In the Red Desert of Wyoming it supplies fully one-half of the winter grazing. NuttalFs salt sage is worthy of introduction inta 3 A98 35 546 YEARBOOK OF THE DEPARTMENT OF AGRICULTURE. cultivation along with the Australiaii aaltbu&hes, and wherever it now occurs on the ranges care should be taken not to extenninixte it. SPirfY SALT SAf5.E. Spiny salt sage {Atriplex confertifoUa) is a perennial, spreading shrub, with numerous, short, thick leaves and spiny branches. It grows 2 or 3' feet high in cltimps 4 to 6 or 8 feet in diameter. The leaves and fruits drop off in autumn and are collected in the depres- sions of the surface or form little wind drifts behind the bushes. These piles of leaves and seeds are the first to be eaten by the sheep and cattle when they enter the winter pastures. The spiny branches are also browsed to the ground. This salt sage is ap- parently more resistant to strong alkali than almost any of the others, as it often occurs on "greasewood lands" containing a large amount of sal soda. It grows from the Dakotas, Mon- tana, and Idaho southward to Mexico. Spiny salt sage will probably not improve much in cultivation on account of its woody stems, but on mod^erately »trong black alkali lands it is worthy of cultivation for winter forage. SCRUB SALTBÜSH. Scrub saitbush {Atriplex poly- carpa) is one of the shrubby salt- bushes of California investigated' by Dav>'. It was found growing on gravelly soil containing a maximuDi of 78,000 pounds of salts per acre-foot, considerably more than the Australian salt- Fi-fí. 128.—Nuttairs salt sage (). bush will stand. There are fourteen or fifteen other species of Atriplex in California, mostly confined to the arid alkaline valley lands and the seashores. Many of these contribute to the forage of the region and add value to both winter and summer ranges. Besides these and other closely related shrubby saltbushes there are a number of annuals which are fully as valuable as any of the introduced ones, either in feeding value, amount of seed produc- tion, or resistance to and tolerance of injurious soda salts. FORAGE PLANTS FOR ALKALI SOILS. 547

UTAH SALTBUSH. Utah saltbush {Atriplex truncafa) is one of the best of these annual Si[)eeies. It has much the habit of A. semihaccata, covering the ground with a thick mat of leaves, and thereby preventing evapora- tion,and the rise of alkali to the surface. It is common in northern Utah and Nevada and eastern Oregon on clayey soils imi)regnated with common salt and white alkali. A few seeds were distributed in 189G by the Division of Agrostology, and a number of those who grew it have reported it as being of much promise for the reclamation of alkali soils. It is closely grazed by cattle wherever they have access to it, so that it is hard to find in sufficient amount to supply any quantity of seed. It is never abundant except where undergrazed or protected by fences. TUMBLING SALT SAGE. Tumbling salt sage {Atriplex volutans) is a rank, leafy annual, which forms an upright compact mass 2 or 3 feet high. Nelson says that it may prove more valuable for certain alkali soils than any of the foreign species. It provdu(?cs a great abundance of seed. Tum- bling salt sage gets its name from the fact that, like a great many other plants native to the Western plains and prairies, the stem breaks off close above the ground in autumn and the plant goes roll- ing across the country, scattering its seeds at every bound. It might prove a bad in grain fields because of this tumbling habit. It has very little forage value after the seeds have fallen.

NELSON'S SALTBUSH. Nelson's saltbush {Atriplex pabularis)^ although a perennial, grows rapidly and puts out a gi*eat many stems from the roots each year, so that it would have the value of an annual in cultivation. It has only been collected in the Red Desert of Wyoming, on saline flats along the creeks and in the dry l>eds of alkali basins. Cattle and sheep relish the herbage, grazing it down to the ground each j^ear. It is one of the most promising of the wild saltbushes for cultivation on strongly alkaline soils for winter and summer pasturage.

WINTER FAT AND GREASEW^OOD.

WINTER FAT. Winter fat {Eivrotia lanata) is a white-hairy perennial, 1 to 2 feet high, closely related to the saltbushes, and growing with them on strongly alkaline soils. The cottony seeds are produced in great abundance, and both seeds and stems are eaten greedily by all graz- ing animals, so that this plant is now almost exterminated wherever cattle have free range. It is widely distributed from Manitoba to Texas and westward to the Sierra Nevadas, and wherever it occurs is highly spoken of as a winter forage plant. Experimental cultures of 548 YEARBOOK OF THE DEPARTMENT OF AGRICULTURE. it ill the grass garden at Washington, 1). C, sliow that while it would not rank with the clovers, yet it makes a fine growth on cultivated land. The seed w^as sown on the surface and raked in. Seed might be gathered by ranchmen and sowed in on land which had been disked or liarrow^ed, and while it could not be cut for hay it would make excellent w^inter grazing for either sheep or cattle. It thrives on alkaline soils and will tolerate moderate amounts of the white alkali. Stock grazed on lands wehere winter fat grows make a rapid growth, and are said to be remarkably free from disease because of the tonic properties of this plant. It is worthy of cultivation, and should be given a trial w^herever seed is obtainable from the wild plant. GRE ASE WOOD. The name grease wood is commonly applied to a number of thorny shrubs characteristic of strongly alkaline soils. The common grease- wood, or Chico plant, of the Rocky Mountains, is Sarcohatus verniicii- laius. Its range extends from the Upper Missouri and Platte rivers to the Gila and the eastern slope of the Sierra Nevadas. It grows to the height of 4 to 8 feet. The narrow leaves are usually 1 to IJ inches long, and are very numerous on the young shoots and branches. Many of the latter are thorn-pointed. One would never imagine that this grease wood could have any value as forage, yet cattle and sheep eat the leaves and browse the smaller stems. The seeds are also eaten. An analysis of the ash of this plant at the New Mexico experiment station show^ed 22 j)er cent of potash and 23.9 per cent of soda pres- ent. A sample of soil taken from under one of the plants contained two-tenths per cent of black alkali, while a similar sample taken 20 feet away from the plant show^ed no black alkali. Greasewood devel- ops a thick that goes down 15 or 20 feet or more, and it also sends out lateral surface roots through a radius of from 8 to 12 feet. Large amounts of the soda salts, especially the carbonate, are absorbed. Much of it finds its way into the leaves during the natural processes of growth. Then, as these fall during the winter, there is an accumulation or concentration of soda in the surface soil as a result of decomposition and the leaching out of the soluble sub- stance of the leaves. Greasewood is tolerant of an amount of sal soda that would not only prevent germination of the seeds of cultivated plants, but would destroy the living plants themselves. It is an almost sure indicator of black alkali. Western ranchers recognize the general rule that lands covered with greasewood can not be profitably reclaimed. The Californian greasewood {Allenrolfea occidentalis) is an erect, diffusely-branching shrub, 2 to 5 feet high. It occurs from northern Nevada aiid Utah to western Texas and southern California. Like the preceding, it is one of the characteristic black alkali plants. Davy found it growing in the San Joaquín Valley on a heavy, ^^ellowish FORAGE PLANTS FOK ALKALI SOILS. 549 soil containing from 27,320 to 194,760 pounds of total salts per acre- foot. The minimum of alkalies where this plant was growing is more than the greatest amount borne by any of the cereals. Coville found it on the immediate border of an alkaline marsh in the Death Valley, where such alkali-resistant plants as shad scale, saleratus weed, and mesquite bean were located fully 300 yards back from the barren depression at the center of the marsh. This greasewood is grazed to some extent in winter and adds to the value of the pasturage at that season of the year. CONCLX^SIONS. Wheat and beardless barley can be grown for hay on land so strongly alkaline that alfalfa would neither germinate nor grow. The salt- bushes hold relatively as much advantage over the cereals in the mat- ter of tolerance of alkalies as the cereals do over alfalfa. The native salt sages and greasewood will supply considerable forage where neither wheat, alfalfa, nor the saltbushes will thrive. The early solution of the alkali problem in the West is of great importance because of the extensive areas affected. There are thou- of square miles of alkali lands which, if they can be perma- nently freed from the excessive accumulations of soda salts, are poten- tially as rich in plant foods and as capable of producing large crops of the cereals, fruits, and vegetables as any lands in the . The possibilities for increase in value by the transformation of such extensive alkali areas from a low rate of productiveness to a high one are almost unlimited. In many localities it is simply a matter of the more intelligent use of water on irrigable lands; in others a bene- ficial change maybe accomplished by the substitution-of improved methods of soil cultivation and drainage. On lands not subject to a fourfold benefit may be secured by growing alkali-tolerant forage crops: (1) The surface will be shaded by the dense growth and the rise of alkali checked; (2) the total amount of forage may be increased, often tenfold, enabling the rancher to carry an additional number of stock on the same acreage; (3) there will be an improve- ment in the physical condition of the soil through increase of the amount of organic matter; (4) a gradual diminution of the amount of deleterious salts by removal in the plants themselves.

RECOMMENDATIONS. Complaints are sometimes made that saltbushes, salt sages, and greasewood are unsafe feed for cattle and sheep. These plants are all quite rich in muscle-forming crude i3rotein, especially in the spring. Losses from feeding on them are due to *'hoven," or bloat, a disease which is common wherever stock are permitted to gorge on rich or succulent vegetation, and not to any inherent poisonous properties in the plants. Care should therefore be taken not to allow stock to overeat when first turned out on the saltbush pastures. 550 YEARBOOK OP THE DEPARTMENT OF AGRICULTURE.

The saltbushes and salt sages, botli introduced and native, although experiment.ed with in cultivation only twenty years, have proved to be of value in all alkali-impregnated soils. A more extended cultiva- tion of saltbushes is recommended throughout the West, and while trials are being made with the Australian species, the native foi-ms that have been produced by natural processes, many of them being fully as leafy and having as succulent herbage, should not be over- looked. It is probable that quite a number of the thirty or more salt sages and saltbushes that grow wild on the high plains, mesas, and deserts of the West would, if only given an equall}^ favorable oppor- tunity, prove to be as well adapted to cultivation as any of the foreign species. Such plants as saltbushes, or even sagebrush and grease- wood, will prove of great value where the cereals and garden crops will not grow because of the alkali in the soil. The plants native to any region are the most promising for cultivation in similar regions. Following this law the plants native to alkali soils are the ones for those soils. As the West is developed the amount of grazing land is each year decreasing in extent, and as the better-grassed, natural pastures are devoted to the cultivated crops, the extensive areas of alkali-impregnated soils will become more valuable. The increase of these soils in value in the estimation of the Western cattle growers will come through their utilization in the production of saltbushes and other alkali-tolerant forage plants.