MAMMOTH CLOVER

Mammoth Clover (Trifolium magnum) was long ago named Trifolium medium by LinnÆus. However appropriate the designation may have been at the time, it is not so now, at least under American conditions, as in this country there is no other variety of clover so large, unless sweet clover (Melilotus alba). To apply to it the distinguishing term medium, therefore, is positively misleading, since the smaller variety of red clover commonly grown occupies such middle ground, as the term medium would indicate. Because of this, the author has ventured to designate it Trifolium magnum. It has also been classified, and with no little appropriateness, Trifolium pratense perenne, which has reference to the mildly perennial habit of growth in this plant. In common phrase it is known by such names as Large, Tall, Saplin or Sapling, Giant, Meadow, Perennial Red, Red Perennial Meadow, Pea Vine, Zigzag, Wavy Stemmed, Soiling, and Cow clover or Cow grass. Each of these names has reference to some peculiarity of growth in the plant. For instance, the terms Large, Tall, Saplin and Giant have reference to the size of the plant; and the terms Pea Vine, Zigzag and Wavy Stemmed to the somewhat irregular and trailing habit of growth in the stems, and so of the others. The designation Cow grass is an English term.

Mammoth clover is a large variety of red clover; in fact, the largest variety of red clover in America. The plants are strong, stronger than those of the medium red variety, and the stems are much larger. They are softer than those of the medium red, which to some extent may account for the less erect habit of growth which characterizes it. The leaves are usually destitute of the white spot found on those of the other variety. The heads are also probably larger and somewhat more open, but there is no appreciable difference in the size of the seed. The plants, notwithstanding, bear so much resemblance to those of the common red variety that it is not easy to distinguish them unless by the large size of the plants of the former. The roots are larger and stronger than those of the medium red variety, and as a result have more power to gather plant food in the soil.

Mammoth clover is biennial under some conditions and under others it is perennial, although it is not usually a long-lived perennial. It has a stronger habit of growth than the medium red, and is, therefore, rather better fitted to thrive under adverse conditions, more especially when it has once obtained a hold upon the soil. It grows chiefly in the first half of the season, and makes but little growth, relatively, in the autumn, or, indeed, any time the same season after the crop has been harvested for hay. In the Northern States it comes into flower about the middle of July, and in those of the South correspondingly earlier.

It is relished by all kinds of domestic animals kept upon the farm, but the hay is relatively better adapted to cows and other cattle than to horses and sheep. If cut too late, or much injured in the curing, it is too dusty for horses, and the growth is too coarse to make first-class hay for sheep. It makes excellent soiling food, because of the abundance of the growth and the considerable season during which it may be fed in the green form.

It is peculiarly valuable as a fertilizer and as an improver of soils. In addition to the nitrogen which it draws from the air and deposits in the soil, it brings up plant food from the subsoil and stores it in the leaves and stems, so that when fed it can be returned to the land. It also fills the soil with an abundance of roots and rootlets. These render stiff soils more friable, and sandy soils less porous; they increase the power of all soils to hold moisture, and in their decay yield up a supply of plant food already prepared for the crops that are next grown upon the ground.

Mammoth clover may also be utilized with advantage in lessening the numbers of certain noxious weeds, and in some instances of eradicating them altogether. This it does in some instances by smothering them, through the rankness of the growth. In other instances it is brought about through the setback which is given to the weeds by first pasturing the crop and then cutting it later for seed.

Distribution.—Mammoth clover has long been grown in several of the countries of Europe and Western Asia. It is also grown in certain parts of Siberia. It was doubtless introduced into the United States from Europe by emigrants from that continent, but when exactly is not known. It has probably been many years since its introduction into America, but it is only within the more recent of the decades that it has attracted general notice. In some areas in this country it grows with great luxuriance, fully equaling, if not exceeding, the crops grown in any part of Europe.

Mammoth clover calls for climatic conditions about the same as those for medium red clover. (See page 61.) It flourishes best in moist climates of moderate temperature, and it will endure more drought than the medium red variety and possibly more cold.

The distribution of mammoth clover covers nearly all the States of the Union, but as with medium red clover the adaptation for it is relatively higher in the Northern than in the Southern States of the Union. The highest adaptation for mammoth clover is probably found in certain parts of Michigan, Wisconsin, Minnesota, the northern valleys of the Rocky Mountain States, the elevated portions of those further south and the country around Puget Sound. The adaptation is also high in much of New York, Ohio, Indiana, Illinois, Iowa, Missouri, Kansas and Nebraska. In the Southern States that lie northward, good crops may be grown in some locations, but not in all. As the semi-arid belt is approached, mammoth clover will grow further west than the medium red, but in the greater portion of this region it will not succeed. The adaptation of the North Atlantic States, including those of New England, is not of a high order, but rather more so, probably, than for the medium red.

In Canada also the adaptation of medium and mammoth clover is much the same as for the medium red. In some parts of Ontario, especially Western Ontario, it grows remarkably well; but in the maritime provinces it does not grow so well; nor does it thrive in the provinces of the Canadian Northwest as it does in Ontario.

As with medium red clover, the distribution of this variety has not been fully determined in either the United States or Canada, more especially on soils of the prairie, where it does not succeed well at present. It is probable that under some conditions on these soils, and also in the South, the absence of the requisite bacteria in the soil may account, in part, at least, for failure in attempts made to grow it. With the introduction of these, the area of successful cultivation may be considerably extended.

Soils.—Mammoth clover may usually be successfully grown in soils well adapted to the growth of the medium red variety. (See page 65.) This means that it will usually grow with much luxuriance in all areas which produce hardwood timber, and are usually covered with a clay or muddy loam soil underlaid with clay. It will also grow with great luxuriance in the volcanic ash soils of the irrigated valley lands of the Rocky Mountain States, and in the loam and light loam soils of the Puget Sound country. It has greater power than the common red variety to grow in stiff clays, in sandy soils underlaid with clay, and in areas where moisture is insufficient near the surface soil. In stiff clays the roots penetrate to a greater distance than those of the medium red variety and gather more food. Consequently, a stiff clay soil that would only furnish a light crop of the medium red variety in a dry season may furnish an excellent crop of the mammoth. The quality of the hay is likely to be superior to that grown on soils altogether congenial, since it is not likely to be over-rank or coarse.

On sandy soils underlaid with clay, and especially where the clay is some distance from the surface, this clover is more certain to make a stand, since the vigor of the plants enables them to gather food until the roots go down into the clay.

In areas where the moisture is more or less deficient, the other conditions being favorable, this clover can send its roots down into the subsoil, where moisture is more abundant than on the surface. Because of this power, it is better adapted than the medium red to much of the area of Southwestern Minnesota, Western Iowa, Western Kansas and Nebraska, and, in fact, much of the area bordering on the semi-arid country.

On clay soils that are so saturated with water that in the winter or spring the clover is much liable to heave, there is conflict in opinion as to whether the mammoth or the common red variety will heave the more readily, but the preponderance of the evidence favors the view that the roots of the mammoth variety can better resist such influences than those of the common red.

This clover, like the common red, is not well adapted to hungry, sandy soils, to the blow soils of the prairie, to the muck soils of the watery slough, or to the peaty soils of the drained muskeg.

Place in the Rotation.—The place for mammoth clover in the rotation is much the same as for the medium red variety. (See page 70.) It may, therefore, be best sown on a clean soil; that is to say, on a soil which has grown a crop the previous season that has called for clean cultivation, as, for instance, corn, potatoes, sorghum, or one or the other of the non-saccharine sorghums, field beans, soy beans, cow peas and field roots. But it is not so necessary that it shall be made to follow either kind of beans or cow peas as the other crops named, since these have already gathered nitrogen, which is more needed by leguminous crops. This clover should rather be grown in rotations where more nitrogen is wanted, when the soil will profit by increased supplies of humus, and where strong plants are wanted, the root growth of which will have the effect of rendering the cultivated portion of the soil more friable when stiff and more retentive when sandy, and that will have the effect of opening up many little channels in the subsoil when the roots decay, through which an excess of surface water may percolate into the subsoil. It may precede such crops as revel in humus and that feed ravenously on nitrogen. These include all the small cereals, corn and all the sorghums, rape, and all kinds of garden vegetables and strawberries. It is, of course, better adapted to short than to long rotations, because of the limited duration of the life of the plants.

The length of the rotation will, of course, depend upon various contingencies. Frequently, the clover is cropped or pastured but one season following the year on which the seed was sown, whatsoever the character of the crops that precede or follow it, but in more instances, probably, it is used as crop or pasture for two years. When timothy is sown along with this clover the pasturing or cropping may continue for one or more seasons longer before the ground is broken, but in such instances the timothy will have consumed much or all of the nitrogen put into the soil by the clover, save what has escaped in the drainage water. One of the best rotations in which to sow mammoth clover, as also the medium red, is the following: Sow in a nurse crop of rye, wheat, oats or barley, as the case may be, in order that it may be pastured or cut for hay the following season, and then follow with a crop of corn or potatoes. This in turn is followed by one or another of the small grains. This constitutes a three years' rotation, but in the case of mammoth clover it is frequently lengthened to four years. The year following the sowing of the clover, it is cut for hay or for seed, and the next year it is pastured with or without a top-dressing of farmyard manure. This rotation meets with considerable favor in certain areas of Wisconsin, well adapted to the growth of the plant.

Preparing the Soil.—The preparation of the soil called for by the mammoth clover is virtually the same as that required when preparing a seed-bed for the medium red variety. (See page 74.) Clay loam soils, whatsoever their color, cannot easily be made too fine and smooth, and the same is true of sandy loams. Stiff clays should be made so fine as to contain ample loose mold to germinate the seed readily, and yet they ought not to be made so fine that they will readily run together under the influence of a soaking rain. Usually, such soils are seldom made too fine, but sometimes they are. The aim should be to firm sandy soils, especially when light enough to lift with the wind, and to leave them more or less uneven on the surface when the seed is sown.

In many States the ground should be plowed in the fall for spring sowing, and in yet others it should be plowed in the spring. Conditions of soil and climate govern this feature of the work. Usually, however, the longer the soil is plowed and then properly worked on the surface before receiving the seed, the finer, cleaner, firmer and moister it is likely to be, and the larger the store of the available fertility to promote the growth of the young plants. Because of this, after cultivated crops, the ground is not usually plowed or otherwise stirred on the surface.

When the soil is low in fertility, it may be necessary to fertilize it before a crop of mammoth clover can be successfully grown. For such fertilization, farmyard manure is very suitable. When soils are low in the content of humus, before a good crop of clover can be grown, it may be necessary to supply humus. But few soils are so deficient in fertility that they will not grow clover if supplied with humus. Farmyard manure supplies both humus and fertility, but in its absence, a crop of rye buried in the soil will insure a stand of clover. In other instances it may be necessary to follow with some kind of a crop that has much power to gather plant food, as corn of some hardy variety, and to graze or otherwise feed it from the land.

Sowing.—Much of what has been said about the sowing of medium red clover will apply also to the sowing of mammoth clover. East of the Mississippi and north of the Potomac and Ohio rivers, mammoth clover is usually sown in the spring, and for the reason that the young plants are frequently killed by the severity of the winter weather when sown in the autumn. But when sown at that season, the seed being mixed with winter rye and being deposited by the drill as early as September 1st, the plants frequently survive the winter as far north as Marquette County in Wisconsin. The rye in the line of the drill marks provides a sufficient protection for the clover. But this only occurs where the conditions are eminently favorable to the growth of the clover. Around Puget Sound it may also be sown with advantage in the early autumn, as then it should produce a full crop the next season, and the same is true of nearly all the Rocky Mountain valley region, but in these areas it may also be sown in the spring. Between the Mississippi and the Rocky Mountains and Oklahoma and Canada, spring sowing is usually preferable, and in much of the area is an absolute necessity to insure a stand. In the South the seed may be sown fall or spring; which season is to be preferred should be determined chiefly by the character of the soil. On soil much given to heaving in the winter it is usually preferable to sow in the spring. In all, or nearly all, parts of Canada spring sowing only is admissible.

When the seed is sown in the early spring, it should usually be sown quite early, as early, in fact, as the ground is in condition to receive the seed when the nurse crop has been sown the previous autumn. When the ground is smooth and impacted on the surface, it is considered preferable to defer sowing until the ground is dry enough to admit of covering the seed with the harrow. When deposited at the same time as spring-sown nurse crops, and with these, the time of sowing will be determined by the most suitable time for sowing the nurse crop. This plant may be sown under certain conditions as late in the spring as moisture exists in the soil sufficient to produce vigorous germination in the seed. This means that it may be sown as late as June, if sown alone, and even later. When sown thus late it should be on soil that has been well cleaned near the surface. When sown in the autumn, as with medium red clover, the aim should be to put the seed in as early as the arrival of the autumn rains, that the plants may be well rooted before the arrival of freezing weather.

Ordinarily, mammoth clover, like the medium red, is sown with a nurse crop, whether sown fall or spring. (See page 84.) The nurse crops in the North include winter rye, winter wheat, barley, spring wheat and oats, suitable, probably, in the order named, also such pasture crops as rape, vetches, and various mixtures of grain sown on certain soils to provide pasture for cattle, sheep or swine. The best nurse crops in the South include winter rye, winter barley and winter oats, even though the seed should not be sown on them until the spring. On certain sandy loam soils a stand of mammoth clover is more assured if sown with a pasture crop than if sown with a grain crop which is to mature. (See page 82.) Under certain conditions of soil and climate, this crop may be sown on plowed or disked land in certain of the States, after a crop of grain, and in other instances by sowing amid the stubbles and covering with the harrow. But there is more of hazard in growing thus than by other methods. Sometimes this clover is sown amid standing corn, at the last cultivation, but too much shade or too little moisture may cause only partial success, or even failure, whereas at other times the plan may succeed.

The modes of sowing the clover are virtually the same as those to be followed in sowing medium red clover. (See page 78.) It will be sown by hand, by hand machines, and by the grain drill, with or without attachments. The seed of this variety, however, will, on the whole, be more frequently mixed in with the grain than the seed of the medium red clover, because of the stronger growth that it makes. This will frequently be found the preferable mode of sowing it when sown in the autumn.

When sown to provide hay, mammoth clover and timothy make an excellent combination for the reasons, first, that they mature about the same time; second, that more of this clover is likely to survive the first year of cutting than of the common red; and third, that more food, it is believed, will be furnished to the timothy in the dead roots of this clover than of the medium red. The first year of cutting, the hay crop is likely to be nearly all clover; the second year, clover and timothy mixed, and the third year, timothy. But if alsike is sown in the mixture, though it may be little in evidence the first year, it will show itself the second year and probably the third year. When sown for pasture in short rotations, this clover may be sown alone or with other varieties of clover, timothy or tall oat grass being added. When sown for seed, it is probably better to sow it alone, but there is no very strong objection to sowing timothy alone with the clover, since the latter may aid in sustaining the clover, and it is not difficult to separate mammoth clover seed and timothy seed.

When mammoth clover is sown alone for hay or for seed, not fewer than 12 pounds per acre of seed should be used. When sown with timothy, 6 and 8 pounds, respectively, would be an average seeding. If alsike clover is added, the seed of the mammoth may be reduced by one pound, and the same amount of alsike added to the mixture. When sown with the medium red variety to provide short rotation pastures, about 6 pounds of each may be sown. The pasture furnished will be more continuous than where only one kind is sown. If timothy or tall oat grass is added, a pound of one or the other of these should be added for every pound of the clover withheld from the mixture. For permanent pastures 6 pounds of the mammoth clover may be set down as the maximum to sow per acre, varying the quantity with varying conditions. And when the clover is sown with small grain to be plowed under in the fall or early in the spring, usually only very moderate amounts of seed ought to be used, especially where the hazard is considerable that the dry weather may cause failure in the catch of the seed.

Pasturing.—Mammoth clover furnishes much pasture when it is grazed, on into July and sometimes even into August, because of the vigorous character of the growth, but after that season the growth is usually light. Nor is there generally much growth after the crop has been cut for hay. The palatability of the pasture is much the same as that of the medium red variety. More grazing is furnished where the crop is fairly well grown before the pasturing begins, but it is not so palatable, and when unduly rank, to defer pasturing thus long would result in a considerable waste of pasture, which the stock would tread under foot. When the crop is wanted for hay, there may be instances in which it may be advantageous to pasture it for a time to prevent the growth from becoming overly luxuriant. There have been instances in which the clover has grown so rankly that the lodged clover killed nearly all the plants by excluding the air from the roots. When grown on soils that in a normal season produce a rank growth, the quality of the hay will, in nearly all instances, be improved by grazing. This, however, should be done soon after the growth begins and should not be long continued, and it should be close, in order to promote evenness and uniformity in the growth of the hay crop.

When grown for seed, mammoth clover is quite frequently pastured. In fact, in a majority of instances it is either pastured or cut with the mower when a seed crop is wanted. The pasturing usually continues until June 1st, but in some instances it is prolonged far on into June. The duration of the pasturing season should be gauged largely by the character of the soil and weather. The better the conditions for growth in the plants, the longer may the pasturing be continued, and vice versa. There are also conditions in which such pasturing may not be necessary. But when the grazing is not close, the mower should be run over the field, otherwise the seeds will not ripen evenly.

There is the same danger from bloating that is present when pasturing medium red clover. (See page 94.) To avoid this danger, cattle that are being thus pastured are in some instances given access to cured clover hay. In other instances the haulm of the seed is left in the field so that the cattle have access to it. But the second season of grazing, the danger from bloat is not so great as the first season, as usually more of other pasture plants grow amid the clover.

Horses, cattle, sheep or swine may be used in grazing off the clover for seed. All of these may be used at the same time. Horses bite the crowns of the plants so closely as to somewhat injure subsequent growth; sheep also crop rather closely; cattle do not crop the plants so closely; consequently, they are so far preferable to horses or sheep for such grazing. On the other hand, sheep will prove far more destructive to weed growth in the pasture.

Harvesting for Hay.—Ordinarily, the methods of making the hay crop are the same as those followed in curing medium red clover. The mammoth variety, however, frequently requires a longer season in which to cure, owing, first, to the heavier character of the growth, and second, to the larger stems of the latter. After it has been mown there is greater reason for using the tedder in getting it ready for being raked, and it calls for more curing before it is put into cocks. The larger the proportion of the timothy in the crop, the more easily it is cured. It is ready for cutting when in full bloom, and loses more than the medium red when cutting is too long deferred, because of the larger proportion of coarse stems in the crop. It is also relatively more injured by rain in the cocks, since it sheds rain even less readily than the medium red clover, and the same is true of it in the stack.

Some farmers cure mammoth clover in its green form in the mow as they also cure the medium red variety, but the same objections apply to curing it thus that apply to the similar curing of the medium red. (See page 102.) Others cure it in the mow by storing good bright straw, preferably oat straw, in alternate layers along with the clover. From one-third to one-half the quantity of the straw as compared with the hay will suffice for such curing, varying with the degree of the wilting in the hay. Clover cut in the morning after the dew has lifted may be thus stored the same day. Where the facilities are present such a method of curing mammoth clover may be eminently wise in showery weather. The natural color of the hay and blossoms is thus preserved and the straw is eaten with avidity, because of what it has imbibed from the clover.

Securing Seed.—It has been already intimated more seed will be obtained when the clover has been pastured or cut back with the mower. (See page 233.) When the mower is used, it should not be set to cut quite low, or the subsequent growth will not be so vigorous as it would otherwise be. The state of growth at which the clover ought to be cut will be influenced by the luxuriance of the growth, but ordinarily clover seed should not be more than 6 to 8 inches high when the mower is used. What is thus cut by the mower is left on the ground as a mulch. Mowing the crop thus will also be helpful in destroying weeds, but some weeds will sprout again and mature seed as quickly as the clover.

When mammoth clover is neither pastured nor mown early in the season, when grown for seed some kinds of weeds may be prevented from going to seed in it by cutting them off with the scythe. When not too plentiful they may be removed with the spud. Among the more troublesome weeds that infest mammoth clover are the Canada thistle (Cirsium arvense), the plantain (Plantago lanceolata), and in some instances the horse nettle (Solanum Carolinense) and spring nightshade (Solanum).

The yields of the clover seed will be much influenced by the character of the weather. Excessive rankness in the crop and excessive rainfall during the blossoming season are adverse to abundant seed production. But the seed crop is more injured by drought than by too much rain. When injured by drought the growth will not be sufficiently strong, or, if it is, the blossoms will be of a pale red tint. Warm winds while the seed is forming are also adverse to seed production, since they cause the crop to mature too quickly. Some experience will enable the capable observer to forecast with no little certainty the probable yield of the seed. If the indications point to a yield of seed less than 2 bushels per acre, it is deemed more profitable, as a rule, to cut the crop for hay. Large heads of a rich dark purple shade accompanied by vigor in the entire plant are indicative of abundant seed production.

The crop is ready for being harvested when a majority of the heads have ripened so far that the bloom on them is all gone and the shade of color in the head has not yet become brown. If left until a majority of the heads are brown many of them will break off while being harvested. The crop is usually cut with a self-rake reaper, but it may be cut with a mower. When cut by either method the sheaves should be made small, so that they will dry out quickly.

It is important that the crop shall be threshed before it is rained on, as one thorough wetting will so far bedim the attractive brightness as compared with seed that has not been rained on that it will considerably discount the price that would otherwise be obtained for it. It is usually threshed with a huller, but may also be threshed like the medium red variety by a grain separator with a suitable attachment.

The yields of the seed vary much. Instances are on record where as much as 11 or 12 bushels per acre have been reaped, but ordinarily even on good producing soils the yields are not more than 4 to 5 bushels per acre, and under ordinary conditions for the production of mammoth clover they are even less than the amount named. Notwithstanding the greater strength of the plants, the seeds are apparently no larger than those of the medium red variety, nor can they be distinguished from them unless by an expert.

Renewing.—Much that has been said with reference to the renewing of medium red clover will apply equally to the renewing of the mammoth. (See page 109.) Where seed crops are much grown, the soil becomes so impregnated with the seed that more or less of the plants will appear any season. Renewal in the South is more important, relatively, than in the North, as under some conditions the plants survive for a longer period in Southern soils.

Compared with Medium Red Clover.—1. The mammoth is larger and coarser than the medium red and is considerably less erect in its habit of growth. It has larger and longer roots; hence, it goes down more deeply into the subsoil in search of food.

2. It is, on the whole, longer lived than the medium red variety and has greater power to grow in a sandy soil and under conditions in which moisture is not plentiful.

3. It provides more pasture than the medium red variety during the early part of the season, but not so much after harvest, the season of growth being less continuous then than with the former.

4. The hay which it furnishes is usually considerably more bulky and coarse, and because of this it is not so highly prized by stock.

5. It blooms about three weeks later than the medium red variety and remains a little longer in bloom and seeds more freely, but can only be cut once in a season.

6. It furnishes more green food for plowing under than the medium red; hence, it is, on the whole, a better improver of the soil.