Chapter IV: Alfalfa (1)
Alfalfa (_Medicago sativa_) previous to its introduction into California, from Chili, about the middle of the last century, was usually known by the French name Lucerne. The name Alfalfa is probably Arabic in its origin, and the term Lucerne has probably been given to it from the Canton Lucerne in Switzerland. It has followed the plant into Spain and South America, and now it seems probable that soon it will be known by no other name over all the United States and Canada. It has also been known by names applied to it from various countries for which it has shown high adaptation, as, for instance, Sicilian Clover, Mexican Clover, Chilian Clover, Brazilian Clover, Styrian Clover and Burgundy Clover. In yet other instances, names have been applied to it indicative of some peculiarity of growth, as, for instance, Branching Clover, Perennial Clover, Stem Clover and Monthly Clover.
Alfalfa is upright and branching in its habit of growth, more so than the common varieties of clover. It usually grows to the height of 2 to 3 feet, but it has been known to reach a much greater height. Although possessed of a single stem when the plants are young, the number of the stems increases up to a certain limit, with the age of the plants and the number of the cuttings. Forty to fifty stalks frequently grow up from the crown of a single plant where the conditions are quite favorable to growth, and in some instances as many as a hundred. The leaves are not large, but numerous, and in the curing of the plants they drop off much more easily than those of the more valuable of the clovers. The flowers are borne toward the top of the stems and branches, and they are in a long cluster, rather than in a compact head. They are usually of a bluish tint, but the shades of the color vary with the strain from blue to pink and yellow. The seeds are borne in spirally coiled pods. They resemble those of red clover in size, but are less uniform in shape. The color should be a light olive green. The tap roots go down deeply into the soil and subsoil where the conditions as to texture and moisture are favorable. It has been claimed that alfalfa roots have gone down into congenial subsoils 40 to 50 feet, but usually less, probably, than one-fourth of the distances mentioned would measure the depths to which the roots go. And with decreasing porosity in the subsoil, there will be decrease in root penetration until it will reach in some instances not more than 3 to 4 feet. But where the roots are thus hindered from going deeper, they branch out more in their search for food.
Alfalfa is perennial. In the duration of its growth, no fodder plant grown under domestication will equal it. It has been known, it is claimed, to produce profitable crops for half a century. In some of the Western States are meadows from 25 to 40 years old. Ordinarily, however, the season of profitable growth is not more than, say, 6 to 12 years when grown on upland soils. The meadows usually become more or less weedy or possessed by various grasses, and some of the plants die. The plants at first send up a single stem. When this matures or is cut back the uncut portion of the stem dies down to the crown of the plant, which then sends out other stems. This is repeated as often as the stems are cut down until many stems grow up from one plant as indicated above, unless the plants are so crowded that such multiplication is more or less hindered. The plants grow rapidly as soon as spring arrives, and as often as cut off they at once spring again into vigorous life, where the conditions are favorable to such growth; hence, from one to twelve cuttings of soiling may be obtained in a single season, the former result being obtained in arid climates, where the conditions are unpropitious, and the latter being possible only in congenial soils, where the winters are very mild and where the soils are irrigated. Usually, however, even on upland soils and in the absence of irrigation, not fewer than 3 to 5 cuttings of soiling food are obtained each year and not fewer than 2 to 4 crops of hay.
A number of varieties so called are grown in this country. They differ from each other more, however, in their adaptation in essential properties relating to the quality of the pasture and fodder produced, than in the quality of food product obtained from them. The variety commonly grown from seed produced in the West is usually spoken of simply as alfalfa, while that grown from seed European in origin has been more commonly called Lucerne. The former of these has a tendency to grow taller than the latter and to send its roots down to a greater depth. In addition to these, such strains as the Turkestan, the Rhenish, the Minnesota and Sand Lucerne have been introduced.
The Turkestan variety was introduced by the United States Department of Agriculture during recent years. It was brought from provinces beyond the Caspian in Russia, Asia. The object sought was to introduce a variety that would better withstand the rigors of a climate dry in summer and cold in winter than the variety commonly grown. Some strains of this variety have proved drought resistant to a remarkable degree. It has also shown itself capable of enduring without injury temperatures so low as to result in the destruction of plants of the common variety. In trials made by growers in North Dakota and Northern Minnesota, it has been found able to endure the winter's cold in these areas. But it has also been found that while the plants produced some seed in the Central Mountain States, they did not produce much seed when grown in the Northern States. Unless seed can be secured from plants grown in the latter in sufficient quantities to meet the needs of growers, it is feared that in time some of the hardy characteristics of this variety will be lost if the Central and Southern Mountain States must be relied upon as the American sources of seed supplies.
The Rhenish strain comes from Central Europe. It has been highly commended by some European seedsmen for its hardihood, but it has been as yet grown to only a limited extent in America. The Minnesota strain was doubtless brought to Carver County by German farmers, by whom it has been grown in the neighborhood of Lake Waconia for nearly 20 years. It has been found much hardier than the common variety when grown in that neighborhood, and the endurance of plants grown from seed of this strain far northward has been very pronounced. As this variety produces reasonably good seed crops in Central Minnesota, it would seem reasonable to expect that it will become popular in Northern areas. Sand Lucerne, which comes from Central Europe, has considerable adaptation for poor and light soils, and in trials made at the Michigan experiment station was found possessed of distinctive merit for such soils.
Where alfalfa can be grown freely, it is unexcelled as a pasture for swine, and is in favor also as a pasture for horses. While cattle and sheep grazed upon it are exceedingly fond of it, the danger that it will produce bloat in them is so frequently present as to greatly neutralize its value for such a use. It is a favorite pasture for fowls. In furnishing soiling food where it produces freely, it is without an equal in all the United States. It is highly relished by all kinds of farm animals, not excluding rabbits and goats, and when fed judiciously may be fed in this form with perfect safety. Its high value in producing such food rests on its productiveness, its high palatability and the abundant nutrition which it contains. As a hay crop, it is greatly prized. Even swine may be wintered in a large measure on cured alfalfa hay.
As a fertilizer, the value of alfalfa will be largely dependent on the use that is made of the plants. When pastured or fed upon the farm, the fertility resulting being put back upon the land, it ranks highly as a producer of fertility. But this question is further discussed on page 191. As a destroyer of weeds much will depend upon the way in which it is grown. This question also is discussed again. (See page 185.)
=Distribution.=--It is thought that alfalfa is more widely distributed over the earth's surface, furnishes more food for live stock, and has been widely cultivated for a longer period than any other legume. It is grown over wide areas of Asia, Europe, North and South America, and its cultivation is constantly extending. It was grown on the irrigated plains of Babylon long before the days of Nebuchadnezzar. It was the principal fodder used in the stables of the kings of Persia. From Persia, it is thought, it was brought to Greece about 470 B. C., and that its cultivation in Italy began at least two centuries before the Christian era. Several Roman writers, as Virgil, Columella and Varro, mention it. From Italy it was introduced into Spain and from Spain it was doubtless carried by missionaries of the Roman Catholic Church to Mexico and the South American States which lie west of the Andes, as Peru and Chili. In the arid and semi-arid regions of the Andes, the conditions were found so favorable to the growth of alfalfa that it is now the principal forage crop grown. It is almost certain that it was brought from Chili to California, from which it has spread over much of the cultivated portion of the arid and semi-arid west. Western grown seed is also the chief source of supply at the present time for all the States of the Union.
Fully a century ago attempts were made by Chancellor Livingstone and others to introduce it into the Eastern States, but without much success, owing, probably, to the lack of knowledge on the part of the people as to how it should be grown. The seed at that time was doubtless brought from European sources, probably France. It has been noticed by more recent growers in these States that the results from sowing such seed do not prove as satisfactory as those from American grown seed, but that alone should not sufficiently explain why the attempts to grow alfalfa just referred to were not successful.
But it is not alone in the areas named that alfalfa has proved so helpful to agriculture. In Central Asia and northward it has for long centuries furnished the Tartars with the principal forage crop grown. In Turkestan and other places it will grow under conditions so dry as to forbid the vigorous growth of many hardy grasses. In Southern Asia, from India to Arabia, it has lost none of the popular favor accorded to it long centuries ago. In Southern Russia it is extensively grown, and up and down the basin of the Danube. In the Mediterranean provinces of Southern Europe it is still one of the leading forage crops. In France it stands high in the popular estimate, and also in some parts of Germany. And even in humid England it is grown more or less freely on dry, calcareous soils. And the day is doubtless near when in many parts of Africa, Australia, New Zealand and Eastern South America this great fodder plant will be found capable of yielding abundant harvests. In some parts of Argentina it has been claimed that it grows like a weed.
It is believed by many that alfalfa if exposed to very low temperatures will perish and that it cannot stand as much winter exposure as medium red or alsike clover. This is only true of some varieties. Other varieties, as the Turkestan, for instance, will endure lower temperatures and more exposure than the clovers named. Alfalfa has been grown with some success at the government experiment station, Indian Head, Sask, Canada, and yet it sometimes winter kills in Texas. As with clover, it is injured most by exposure to sweeping winds blowing over it in winter when the mercury is low, and the injury is more fatal just after the removal of a snow covering and when the plants are young. Ice forming over the fields after a sudden thaw and remaining for a time is very liable to kill the plants. It can stand considerably more summer heat than any of the clovers grown northward, as witnessed in the good crops grown in some parts of Louisiana during the hottest weather of summer. Nevertheless, with reference to temperatures, what may be termed a mild climate, such as characterizes Southern France in Europe and Western California in the United States, is best adapted to its growth.
It is better adapted to climates that are dry, where the plants can be irrigated, as then rains do not interfere with the harvesting of the hay. Even in the absence of irrigation, a climate that is reasonably dry is preferable to one where drenching rains frequently fall, which wash away the soil when sandy, or which fill it full of water when composed of clay. But where rains fall frequently and in moderation, as in the northern Puget Sound region, the effect is helpful to the growth of the alfalfa plants, although it may add somewhat to the labor of making alfalfa hay, and to the hazard in curing it. Alfalfa will maintain its hold for years on some portions of the table lands of the mountain States under conditions so dry that the plants can only furnish one cutting of hay in a season. It is safe to assume, therefore, that alfalfa can be grown under a wider range of climatic conditions than any other legume grown in the United States. But the influence which climate should be allowed to exercise on the use that is to be made of it should not be lost from view. In climates much subject to frequent rains in summer, it should be grown rather for soiling food and pasture than for hay, whereas in dry climates, and especially where it can be irrigated, it should be grown for hay, soiling food and pasture, but especially the former.
While alfalfa can be successfully grown in one or the other of its varieties in some portion of every State in the Union, it has its favorite feeding grounds. The best conditions for growing it are found in the valleys of all the Rocky Mountain States, where the growth can be regulated by the application of irrigating waters. In these the conditions southward are superior to those northward, because of the milder climate, which precludes the danger of winter killing by exposure, which occasionally happens in the more northerly of the mountain States, and because of the more prolonged season for growth, which adds to the number of the cuttings. This does not mean that the river bottoms in other parts of the United States will not be found good for growing alfalfa. It can be grown in many of these; in fact, in nearly all of them, and to some extent by the aid of irrigation, if the waste waters were stored, but the deposit soil in these valleys being of much closer texture than that in the western valleys, is, on the whole, lower in adaptation than the soil in the latter.
In the western valleys of the mountain States, alfalfa is the crop around which it may be said that agricultural production centers. It is the principal hay crop of those States. The extent to which it may be grown there is revolutionizing the production of live stock on the ranges, as it is providing food for them in winter, which is fast removing, and will probably soon entirely remove, the element of hazard from live stock dependent on the range pastures for support in that season. The dairy and swine industries in those valleys must largely depend upon it. Fruit orchards must ultimately grow on buried alfalfa meadows, and the rotation of all crops in the same will be largely dependent upon the growing of alfalfa. Next in adaptation to the mountain States are, it is thought, certain soils that lie between the Rocky Mountains and the Mississippi, especially such as are in proximity to rivers, or are underlaid with sheet water not far distant from the surface. But an unusually large proportion of the upland soil in these States, from Central Minnesota southward, have high adaptation for the growth of this plant. Particularly is this true of the soils of Nebraska and Kansas and of considerable portions of Missouri, Arkansas and Louisiana.
In States east of the Mississippi, the adaptation is not so general, and is more dependent on soil conditions than on those that are climatic. In nearly all of the river bottoms of these States it will grow with more or less success. On nearly all upland soils it will also grow well, where the subsoil furnishes naturally good drainage. For the exception, see page 132. But in no State east of the Mississippi, is such a proportion of the area so highly adapted to growing alfalfa as in many of the States west of that river. In other States areas are found in which alfalfa will produce excellent crops, but usually these do not embrace the larger portion of the entire area in any State. In a considerable number of the States such areas are more or less limited, and usually they are distributed variously in the different States; that is, they do not lie side by side. The favorite soil conditions in these are a good loam, preferably more or less sandy and resting upon a porous subsoil.
A more exact idea will be given of relative adaptation in various States in what is now submitted. In California, Nevada, Utah, Colorado and New Mexico, alfalfa is now grown chiefly by the aid of irrigation, and all of these States have highest adaptation for its growth. In some parts of California 6 to 10 tons of cured hay are obtained in one year, with pasture in winter additional. In Utah, good crops have been grown successively on the same land for more than a quarter of a century. In Colorado two cuttings are obtained the first season, and it is said that there the plants are not easily destroyed. It yields enormously in the irrigated valleys of New Mexico and Arizona.
In Washington, Oregon, Idaho, Montana and Wyoming, it is grown with and without irrigation. In large areas in all these States, excellent crops are and may be grown, but the season of growth being shorter, not so many cuttings are obtained per year as in the mountain States further south. In Northern Idaho two cuttings may be obtained per year, even on high, dry land.
In North Dakota, especially westward, alfalfa gives promise of successful growth. It will grow well in much of South Dakota, especially on sandy soils not too distant from water. In Minnesota it has been grown successfully in Carver County since 1886. Good success is being obtained from growing it in other parts of the State, even in some parts of the Red River valley. In Western Iowa it is being grown with much success, and in some portions of Eastern Iowa. In Missouri, the two important centers for growing it are the northwest and the southeast, but in other areas it has also done well. In Kansas it will grow well in all parts of the State where the subsoil is porous. It has been cut for hay in that State in less than 60 days from the date of sowing. It grows equally well over at least two-thirds of Nebraska, especially the eastern half, and its growth in Nebraska is rapidly extending. In the Arkansas valley it luxuriates, and it is also being grown in Oklahoma. In Louisiana immense fields are being grown along the Red River and in other parts of the State. In Texas it is being grown more or less north, east and south, and especially in the valley of the Brazos.
In the Southern States alfalfa has not in many instances been given a good chance where tried. The plants have too frequently had to contend there as elsewhere with ill-prepared and weedy soils and imprudent pasturing. Yet it is being grown with considerable success, though as yet in limited areas, in all the Southern States. It has done well in parts of Kentucky, Tennessee, Mississippi and Alabama, and in Georgia are some alfalfa meadows 25 years old. In the other Southeastern States, viz., Virginia, the Carolinas and Florida, it does well only in areas more or less circumscribed, but it has been grown with some success even in the rainy climate of Southern Florida.
In the States northward from the Ohio River, that is, Illinois, Indiana, Ohio, Michigan and Wisconsin, the necessity for growing alfalfa has not been so much felt as in some other States, because of the excellence of the crops of clover grown in these. Its growth, however, is extending in all of these States. Much of the soil in Illinois, it is said, must first be inoculated with the bacteria proper to alfalfa before vigorous crops can be grown, and this is probably true of sections of Indiana soil. Some sections of Ohio are becoming noted for the crops of alfalfa which they have grown, and in Wisconsin Hon. W. D. Hoard succeeded in securing 5.7 tons of alfalfa hay in one season from four cuttings made on three-fifths of an acre.
In all the Eastern and New England States, alfalfa is being grown to some extent. In some counties of New York, as Onondaga and Madison, it is becoming the leading soiling and hay crop. In Massachusetts it has borne cuttings year after year on sandy loam soil. On Long Island three to four cuttings each season have been obtained for a series of years. It is believed that it will grow over nearly the whole of Southern Maryland and also in much of the eastern part of that State, and its growth has been quite successful in parts of Delaware and Pennsylvania.
Alfalfa will grow well in considerable areas in Canada. The statement would seem safe that at the present time profitable crops could be grown in some parts of every province of Canada in which the land is tilled. In Quebec, even on high land, it usually endures the winters. Near Montreal it has been cut for soiling food at the height of 30 inches as early as May 15th. In some parts of Eastern Ontario good crops can be grown, and also over considerable areas of Western Ontario. The author grew it with much success at the experiment station at Guelph in 1890 and subsequently, and during recent years considerable areas are being grown in several of the Lake Erie counties and in those that lie north from them. But in no part of Ontario are the conditions for growing alfalfa better than in some of the mountain valleys of British Columbia.
But few crops, if, indeed, any, are being experimented with at the present time to so great an extent as alfalfa; hence, the expectation is reasonable that there will be an enormous increase in the area grown in the future that is near. The two chief causes of failure in the past were want of knowledge in growing and caring for it on the part of the growers, and the absence of the proper bacteria in the soil. Acidity in some soils and want of drainage in others are also responsible for many of the failures referred to. But even where it does grow reasonably well, some trouble is found from the alfalfa failing in spots. In some instances the cause can be traced, as when coated with ice in winter, or where the soil is not uniform, but in other instances the precise causes have not been determined. Notwithstanding these drawbacks, however, greatly increased areas will be grown in the future, especially in States in which the dairy interest is paramount or even important.
=Soils.=--It was formerly thought by many that alfalfa would only grow vigorously on soils and subsoils sandy in character, and underlaid at some distance from the surface with water. It is now being ascertained that it will grow on a great variety of soils, providing they are reasonably fertile, free from acidity, sufficiently porous below to carry away water with reasonable quickness, and not underlaid with hard pan or a subsoil so tenacious that it is almost impervious to water.
The best soils for alfalfa are those of the Western mountain States, and in these the deposit soils of the river valleys stand among the foremost. These soils are usually of much depth. Many of them have water underneath, and the subsoil is usually so porous that the roots can go far down in them, such is the character of nearly all the bottom land west of the Mississippi. But in nearly all of the mountain region of the West, from Banff in British Columbia to Mexico, alfalfa will grow well under irrigation, or in the absence of irrigation, if ground water is not too distant from the surface. In this region alfalfa grows more vigorously and more persistently than in almost any other portion of the United States.
In regions where alfalfa is not dependent upon irrigation, the best soils probably are deep, rich calcareous loams, clay or sandy, and underlaid with what may be termed a mild or reasonably porous clay subsoil. With such soils the plants may be in no way influenced by sheet water below, as on some of these in Nebraska, for instance, such water is fully 150 feet below the surface. These soils are usually possessed of abundant food supplies to nourish the plants, and the roots can go far down into the subsoils to gather food and moisture. Such lands are found more or less in nearly all the States of the Union east from the Rocky Mountains; hence, when the requisite bacteria are present, good crops can be grown on them in every State in the Union.
On the ordinary black soils of the prairie, alfalfa will usually grow reasonably well if underlaid with clay not too distant nor too tenacious. When the roots get down into the subsoil, they can usually find much food in the same, and unless in very dry areas a sufficiency of moisture, but in many instances it may be necessary to introduce the requisite bacteria, and to apply farmyard manure to encourage sufficient growth to carry the roots down quickly to the subsoil. In some prairie soils the growth will be vigorous from the start, but usually these are lands that have grown hardwood timber, and that have in them more or less clay.
In climates where the rainfall is considerable, alfalfa will frequently grow well on gravelly soils and on those that are stony. Some of the best alfalfa soils in the State of New York, New England States, and in the Canadian provinces of Quebec and Ontario are of this character.
Alfalfa will frequently grow fairly well even on stiff clays, and in some instances on gumbo soils. But these soils must not be so retentive as to collect and hold water for any considerable time within a few feet of the surface. Such lands have usually much staying power; hence, alfalfa grown on them frequently improves for years after it has been sown. On the reddish soils that cover much of the South, it has been found, as in growing alfalfa on stiff clays in the North, that where deep subsoiling is practiced alfalfa is not only more easily established, but it also grows with added vigor.
On upland soils sandy or gravelly in character where the rainfall is much less than normal and where the subsoil is not underlaid with sheet water, alfalfa will not usually succeed, notwithstanding that it may grow well on these soils where the rainfall is normal. On such soils it is not easy to get a stand of the plants, as they are much apt to perish in the dry weather of the first season, but if once established on such soils the plants have much power to grow even where the rainfall is considerably less than normal.
Alfalfa will not grow well in soils naturally wet until they are drained. And when drained it will not grow with normal vigor, on what may be termed slough soils, where the subsoil is far down and covered with a deep covering of vegetable mold. What are termed slough soils in the Western prairies, therefore, are not well fitted for the growth of alfalfa. On these it may not succeed well, when it may grow with much vigor on the adjoining upland. When some wet soils are drained, alfalfa may not succeed well on them for a time and later may grow luxuriantly. This may arise from the lack of time for proper aeration after being drained, or from the want of lime to further correct acidity in the soil, or from the want of the proper bacteria. Notwithstanding that alfalfa will not grow well on undrained lands that are naturally wet, and notwithstanding that it will perish if the roots reach standing water at a distance too near the surface, the best crops by far are usually grown on irrigated lands. This arises, first, from the ability to adjust the supplies of water to meet the needs of the plants, and second, from the congenial character of the soil and subsoil. Next to these the best crops are grown where congenial soils are underlaid with ground water, not too near nor too distant from the surface. On these soils the plants are largely supplied with moisture from the water below ascending on the principle of capillary attraction. How near or how distant such water should be will depend somewhat on subsoil conditions. It would seem correct to say that it ought never to come nearer to the surface than 3 feet, nor should it be more than 20 feet down. The most suitable distance would be, say, 8 to 16 feet. When the roots of alfalfa reach water at too short a depth they will die.
Alfalfa may sometimes be grown satisfactorily on soils subject to overflow, but usually there is hazard in growing it on these. If the overflow occurs comparatively early in the season, if it is not of great depth, if it is of short duration, and if the waters quickly drain out of the subsoil possessed by the alfalfa, it may receive little or no harm from such overflow. Instances are on record wherein ice has formed on alfalfa and yet the plants survived, but such a condition will usually prove fatal to them. But should the overflow take place in hot weather, usually it will injure the plants seriously, and may, indeed, completely destroy them. So great is such hazard, that care must be taken against the application of an excess of irrigating waters under such conditions. Overflow waters that are stagnant are more injurious probably than those that are in motion, owing, it may be, to the less supply of dissolved oxygen in the former.
Soils suitable in themselves, but lying on stiff clay bottoms or underlaid with hard pan within two or three feet of the surface, will not maintain a good stand of alfalfa. The plants in these may grow well for a time, probably a year or two, after which they will fail. The roots are not able to go down to gather food. When the subsoils are simply stiff clays, deep subsoiling, as already intimated, may render much service, but when composed of hard pan this may not be practicable. In moist climates, however, reasonably good crops have been obtained from soils with underlying rock not more than four feet below the surface.
The fact should not be overlooked that soils may have the requisite physical conditions for growing alfalfa, and they may possess in fair supply the essential elements of plant food, and yet alfalfa will not succeed at the first when sown on these, because of the absence of the soil bacteria, the presence of which is essential to the vigorous growth of the plants. Because of this, growers should be slow to conclude that alfalfa will not flourish on the soils on which they sow it until they have first tried to grow it on those soils that have been inoculated with the requisite alfalfa bacteria. For the methods of procedure in such cases see page 53. Some persons claim that soils which will grow medium red clover in good form will also grow alfalfa in good form. This does not necessarily follow. While there is much of similarity in the soils suitable for the growth of both, alfalfa may fail on lands that grow red clover luxuriantly until the bacteria proper to alfalfa have been introduced. Soils may be tested for bacteria, and even in winter, by sowing some seed in pots and treating them like well-cared-for house plants. When the plants are 2 to 3 months old, if tubercles are found on the roots, the conclusion would seem safe that such soil does not require inoculation.
=Place in the Rotation.=--In a certain sense it can scarcely be said of alfalfa that it is a rotation plant, because of the long term of years for which it is grown in an unbroken succession. Nevertheless, in all places it cannot always be maintained for a long term of successive years without renewal. In the Eastern States it is frequently, though not always so crowded by various grasses, that the fields in which it grows are broken up at some period short of ten years, and not infrequently at the end of five or six years. When thus grown, it becomes a rotation plant, though grown in what may be termed long rotations. But even in the West, where, under irrigation, it may be grown for a quarter of a century or even for a longer period without renewal, it may be used when desired in short rotations. In such situations it grows so readily and becomes established so quickly, that the fields may be broken with a view to alternate with other crops at the end of the second year, or of any year subsequently from the sowing of the seed that may be desired. Alfalfa in these soils will serve even better than medium red clover in such situations, since while it is growing, it will produce more hay or soiling food, and consequently should excel the former in the fertility which it makes available.
East of the Mississippi and north of the Ohio River, alfalfa will frequently follow cultivated crops, as corn, potatoes and field roots, and when the fields are broken, it will be followed by crops other than legumes. On many soils the influence which this crop has on relieving the surface soil from excessive moisture, through channels opened into the subsoil by the decaying roots, is so helpful as to considerably stimulate production in addition to the fertilizing influence which it exerts directly. Particularly good crops of corn, the small cereal grains, and even field roots may be grown after alfalfa.
On soils east of the Mississippi and south of the Ohio, the rotation will be somewhat similar. But on Southern soils alfalfa will frequently follow immediately crops especially grown to be plowed under as green manures for the benefit of the alfalfa. These crops include cow peas, soy beans, crimson clover, and to a limited extent, burr clover. It will also be followed frequently by crops of cotton and other non-leguminous plants, the growth of which in the United States is confined to the area now being considered.
In the area west of the Mississippi and east of the semi-arid region beside the mountains, alfalfa may follow the small cereal grains, and may in turn be followed by them and also by millets. It may also follow and precede corn, or the non-saccharine sorghums, where the climatic conditions are suitable for growing the latter.
In the irrigated regions of the West, alfalfa may be made to serve almost any purpose in the rotation that may be desired. By growing it as a rotation crop in these valleys it may be made to furnish the soil indefinitely with supplies of nitrogen and humus. In these soils it may be made to follow directly almost any crop grown on them, and similarly it may be made to precede the growth of almost any crop for which the locality has marked adaptation. Small cereal grains, timothy, vegetables, field roots, potatoes, corn, small fruits and orchards may be profitably grown on buried alfalfa meadows. This does not imply, however, that alfalfa meadows should not, as a rule, be maintained for a long term of years.
=Preparing the Soil.=--In preparing the soil for alfalfa the aim should be to make a seed-bed clean, rich, fine, moist, even, and sufficiently firm or friable, according to the conditions. The subsoil should also be made sufficiently dry and open. From what has just been said, it will be apparent that in properly preparing the seed-bed, it will be necessary to study closely the requisite conditions.
The advantage from having a clean seed-bed will be apparent when it is called to mind that alfalfa is a somewhat delicate plant when young, and that because of this, it is ill able to overcome in the fight with weeds. Cleanness in the surface soil may be obtained by summerfallowing the land, by growing a root crop or a crop of corn or any of the non-saccharine sorghums. When the seed is spring sown, this preparation must be given the year previously, but when autumn sown, it may be given the same season. In preparing the land thus, the aim should be to make the surface as clean as possible, rather than to get weed seeds out of the lower strata of the cultivated soil, in which they will likely perish before the field sown to alfalfa is broken up again. Summerfallowing makes an excellent preparation for the land, because of the fine opportunity which it furnishes for cleaning the same perfectly and leveling it off properly. The excellent condition in which it puts the seed-bed, viewed from the standpoint of the duration of the years of cropping that are likely to follow, would seem to more than justify such preparation of the land. The outcome may more than justify the loss of the crop for one season when thus summerfallowing the land. But it may not be necessary to lose the production of one season whether the seed is sown spring or autumn, as the summerfallowing in the North may follow the pasturing off of some crop, and in the South the interval for fallowing the land may be sufficiently long after the harvesting of an early winter grain crop, before sowing the seed in the autumn. (See page 136.)
When sowing the seed autumn or spring, on land that is filled with weed seeds near the surface, it is frequently better to defer sowing the seed for some weeks to give time for sprouting many of these than to sow at once. This suggestion is specially applicable to spring sowing. It should also be mentioned that when the weeds infesting the soil are annual or even biennial in character, the harm done to the alfalfa by these will be much less than when the land is infested with perennials at the time of sowing. The former may be prevented from seeding by clipping back frequently, while the latter remain in the soil, increase from year to year, and injure the plants by crowding. Where crab grass grows abundantly, as in some parts of the South, unless the alfalfa is sown and cultivated, spring sowing ought to be avoided. But it is less objectionable to sow alfalfa on land that is weedy when the adaptation of the land for the crop is high than when it is low, as the alfalfa in the former instance has so much more power to fight its own battle. On good alfalfa soils, therefore, it may be wiser in some instances to sow alfalfa in weed-infested land than to defer sowing for a whole year in order to clean the land.
It is greatly important that the land shall be rich in available plant food on which the seed is sown. If naturally poor, it should be well fertilized before sowing. When this cannot be done, it is better not to sow. A vast preponderance of the land in the Rocky Mountain region, when first broken, would seem to possess abundantly all the essential foods required by alfalfa; hence, for a time, at least, it is not necessary to enrich these before sowing the seed. The sandy and hungry gravelly soils, which are considerable in the South, in the Atlantic States, and in some of the Central and Northern States, should be fertilized before laying them down to alfalfa. Such fertilization usually calls for both humus and readily available plant food, and these are most cheaply supplied by growing certain green crops and plowing them under, or by applying farmyard manure. These may be supplemented when necessary by commercial fertilizers. Some precede alfalfa on such soils by growing cow peas or soy beans, followed by crimson clover, both crops being plowed in, and shortly before sowing the alfalfa they apply more or less of phosphoric acid and potash, which is usually incorporated in the surface soil by the harrow. On some soils, as in some parts of Florida, two successive crops of cow peas should be plowed under before sowing alfalfa. When farmyard manure can be used in fertilizing those leechy soils it is well when it can be applied on the surface in a somewhat decomposed form and also kept near the surface during the subsequent cultivation given when preparing the seed-bed. In the North it is best applied in the autumn or winter, and in the South in the summer. But on loam soils with a reasonably retentive subsoil, the better way to apply farmyard manure is to make a heavy application of the same to the crop preceding the alfalfa. It has thus become incorporated with the soil, and many weed seeds in it will have sprouted before sowing the alfalfa. The results from applying manure on soil somewhat stiff and not highly productive have been noticeably marked. This may have been owing in part to the mechanical influence of the manure on the land. The relation between the free application of farmyard manure and abundant growth in alfalfa is so marked in all, or nearly all, soils west of the Mississippi River that in many instances better crops will be obtained from poor soils well manured than from good soils unmanured. The relation between abundant manuring and soil inoculation is worthy of more careful study, in the judgment of the author, than has yet been accorded to it.
Fine pulverization of the surface soil is advantageous when sowing alfalfa, because of the influence which it has upon the retention of moisture near the surface, and upon the exclusion from the soil of an overabundance of light. It is in clay soils, of course, that this condition is most difficult to secure. The agencies in securing it are the cultivator, the harrow and the roller, and in many instances the influences of weather, after the land has been plowed, especially when plowed in the autumn prior to spring seeding.
Moistness in the seed-bed sufficient to promptly sprout the seed is a prime essential, but it is very much more important where the seasons are dry than where the lack of rain is but little feared. When the seed is sown after summerfallow or cultivated crops, it is usually considered preferable to make the seed-bed without using the plow, but to this there may be some exceptions. If sowing is deferred for a few weeks in the spring on such lands, or on other lands autumn plowed or early spring plowed, a free use of the harrow ought to be made in the interval, because of the favorable influence which this will have on the retention of moisture. In preparing some soils for autumn sowing after a grain crop, as in some parts of Nebraska and Kansas, it is only necessary to use the harrow; in preparing others the disk and harrow; and in yet others the disk and harrow and roller. In preparing other soils, as the clays of the South, it may be necessary first to plow and subsoil, and subsequently to use sufficiently the harrow and roller.
Evenness in the soil on the surface is important when it is so retentive that water may collect in the depressions after heavy rain. In such places the plants are much liable to fail, especially in the early winter, or even shortly after they may have begun to grow, if moisture is excessive. In order to smooth and even the land sufficiently, it may be necessary to run over it some form of leveller. This does not mean, however, that it will not be necessary sometimes to plow the land in ridges, or "lands," as they are sometimes called, but it does mean that the slope from the center of the lands toward the furrows shall be even and gradual, in order that an excess of surface water, as in rainy climates, shall be carried away by the latter.
Firmness in the seed-bed is necessary chiefly to prevent too much drying out near the surface in dry weather, and the holding of too much water in the spaces between the particles near the surface in wet weather, followed by freezing of the soil. The less deep the stirring of the cultivated portion when preparing it, the longer the interval between such stirring and the sowing of the seed, and the heavier the pressure when rolling, the more firm will the seed-bed be. The deeper the land is plowed, therefore, the longer should be the interval before it is sowed, but ample rainfall will shorten this period. Firmness in the seed-bed is more important, relatively, in summer or early autumn when evaporation from the surface soil is the most rapid. On some soils of the Middle States which border on the Mississippi, the early sown autumn crop will sometimes perish after the plants have grown some distance above the ground, because of want of firmness in the soil; hence, in such locations harrowing the surface of the ground thoroughly may sometimes be a more suitable preparation than plowing and harrowing.
Friability in the seed-bed is important when the soils are heavy. The influences which promote it are the presence of humus, liberal cultivation, and sometimes weather influences, as rain and frost. Unless heavy clay soils are brought into this condition, the roots of the alfalfa will not be able to penetrate the soil quickly enough or deeply enough in search of food.
As has been intimated, it will not avail to sow alfalfa in soils not sufficiently drained naturally or otherwise. Usually, good alfalfa soils have sufficient drainage naturally, the subsoil being sufficiently open to admit of the percolation of water down into the subsoil with sufficient quickness. But good crops of alfalfa may be grown on subsoils so retentive that underdrainage is necessary to facilitate the escape of an excess of moisture with sufficient quickness. The question has been raised as to whether the roots of the plants will be much liable to enter and choke the drains at the joints between the tiles. While it would not be safe to say that this would never happen, it is not likely to happen, owing to the character of the root growth. Where too much water is held near the surface, in climates characterized by alternate freezing and thawing in winter, the young plants will certainly be thrown out through the heaving of the soil.
The subsoiling of lands not sufficiently open below will be greatly helpful to the growth of alfalfa. This may also be true of lands not over-retentive naturally, but made so by the treading of the animals for successive years on the soil under the furrow when plowing the land. In some conditions, without subsoiling thus, the growing of alfalfa will not be successful, but in doing this work, care should be taken not to bring up raw subsoil to the surface. In subsoiling for alfalfa, usually the more deeply the ground can be stirred by the subsoiler, the better will be the results that will follow. Subsoiling is particularly helpful to the growing of alfalfa on many of the clay soils of the South.
In the far West, toward the mountains, and probably within the same, are areas in which excellent stands of alfalfa may be obtained by simply sowing the seed on surfaces stirred with a disk or with a heavy harrow weighted while it is being driven over the land. The implements should be driven first one way and then the other, and, of course, the seed is harrowed after it has been sown. Where the soil is sufficiently level, this plan of preparing will prove satisfactory, more especially where water can be put upon the land, but it will also succeed frequently in the absence of irrigating waters. In some instances the disking and sowing are both done by the same implement, which is driven both ways across the field.
Alfalfa is sometimes sown, and with profit, on steep hill sides which are inclined to wash. When set on these it tends to prevent the washing of the land. In such situations it is better to sow with a nurse crop, which will help to hold the soil until the alfalfa becomes rooted. Where land is so loose as to blow and irrigation cannot be practiced, only as much should be sown each season as can be covered with stable litter and well-rotted straw drawn out at the proper season.
=Sowing.=--The best season for sowing alfalfa will depend upon such conditions as relate to soil, moisture and climate. On rather stiff clay soils, the other conditions being right, the most satisfactory results are obtained from sowing the seed in the spring, and on land that has been plowed in the autumn and exposed to the mellowing influences of winter. But to this there may be some exceptions. On lands so light as to lift with the wind, that season should be avoided in sowing, if possible, when lifting winds prevail. Such winds are common in some localities in the spring, and may uncover the seed in some places and bury it too deeply in others.
Where moisture is deficient the seed must be sown at those times when it is most plentiful. This may be in the autumn, but more commonly it is in the quite early spring. In some of the mountain States the best results have been obtained under semi-arid conditions from sowing the seed in the late autumn, so that it would be ready for germination at the first commencement of the period of growth in the spring. Under some conditions the too dry character of the weather may preclude the sowing of alfalfa in the summer and autumn months. Where moisture is plentiful all the season of growth, alfalfa may be sown almost any time, except the early spring or late autumn. Where irrigating waters are plentiful, the only hindrances to sowing alfalfa at any season of the year are such as may arise from climate. Far South in very mild areas it may be sown almost any time.
Where the temperatures are low in winter, the best results are obtained from sowing alfalfa in the spring and early summer, otherwise the plants do not become sufficiently well established to withstand the rigors of the winter following. Under some conditions, sufficiently satisfactory results follow sowing in the early summer, even in Northern latitudes. Where the winters are sufficiently mild and the moisture is sufficiently plentiful, early autumn sowing, as in August or September, according to the locality, is, all things considered, the most satisfactory, for the reason, first, that it follows, or may follow, a crop grown the same season; second, that the plants are less hindered in their growth by weeds when they are young; and third, that they produce crops of soiling food or hay the first season after sowing. Many weeds do not grow in autumn and winter; hence, the less injury done by them to alfalfa plants, since the latter are so strong by spring that they overshadow the weeds in their effort to grow. When alfalfa is sown at such a time, the growth of one year virtually is gained by the process.
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Clovers and How to Grow ThemChapter IV: Alfalfa (1)
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