Clovers and How to Grow Them

by Thomas Shaw

The seed is frequently threshed with the ordinary threshing machine, but in many instances it is also threshed with a clover huller. The huller does the work less quickly, but probably, on the whole, more perfectly. Threshing machines, with or even without certain adjustments in the arrangement of the teeth in the cylinder and concave, and with extra screens, are now doing the work with much despatch, and with a fair measure of satisfaction. But the opinion is held by competent judges that a machine that would more completely combine the qualities of the thresher and the huller would be still more satisfactory. It is easily possible to have the crop too dry to thresh in the best condition, and care should be taken to regulate the feed in threshing so that the alfalfa will not enter the cylinder in bunches. More than 200 bushels of seed have been threshed in a day from crops which yielded abundantly. The seed should be carefully winnowed before putting it on the market. The seed crops, as would naturally be expected, vary much; crops are harvested which run all the way from 1 to 20 bushels per acre. From irrigated lands the yields are, of course, much more uniform than from unirrigated lands, since in the former the supply of moisture may be controlled. Fair to good average yields on these may be stated at from 4 to 6 bushels, good yields at from 6 to 8 bushels per acre, and specially good yields at from 10 to 12 bushels. The bushel weighs 60 pounds. Growing alfalfa seed under irrigation has frequently proved very profitable. The seed grown in such areas is larger and more attractive to the eye than that ordinarily grown in the absence of irrigation, and because of this many are lured into sowing it on unirrigated land when the former would better serve their purpose. The seed is frequently adulterated with that of yellow clover (Medicago lupulina), which resembles it closely, but this is more likely to be true of imported than of American grown seed.

Renewing.—Alfalfa may be renewed and also renovated where the stand secured at the first has been insufficient, where it may have been injured from various causes, where it is being crowded with weeds, and even with useful grasses, and where the land requires enriching.

The stand of alfalfa secured is sometimes thin and uneven. This may arise from such causes as sowing too little seed; whether over-dry or through the crowding of the young plants. When this happens, in many situations it is quite practicable to thicken the stand by disking the ground more or less, adding fresh seed, according to the need of the crop, and then covering the seed thus added with the harrow. Such renovation would be comparatively easy on clean land, were it not for fact that the alfalfa plants already rooted overshadow the young plants, always to their injury, and sometimes to their total destruction. The spring will probably be the best season to attempt such renovation, but there may be instances where the winters are not severe, in which autumn seeding will succeed as well or better than spring seeding. Because of the uncertainty of the results of such renovation, the aim should be so to prepare the land and sow the seed that a good, thick stand will be secured at the first.

Should the alfalfa fields be spotted, because in places the nurse crop lodged and smothered the plants, or because excessive moisture destroyed them on the lower portions of the field in an abnormally wet season, the renewing process is simple indeed. It consists in disking those parts so thoroughly as to destroy all vegetation that may have become rooted on them, and sowing seed in the usual way without a nurse crop. But should the low places be such as to hold an excess of water at any time of the year under normal conditions for days in succession, even though it should not rise to the surface, the attempts to make alfalfa grow successfully on these will prove abortive.

When weeds and grasses crowd the crop, the plan of disking the fields to destroy these is becoming quite common, especially in the West. The work is usually done in the early spring. In doing it, disk harrows are driven over the field, usually two ways, the second disking being done at right angles to the first. The disks are set at that angle which will do the least injury to the plants, and that will at the same time do the work effectively. This can only be determined by actual test in each instance. Some of the crowns of the plants will be split open by the disk, which some authorities claim is an advantage in that it tends to an increase in the number of the stems produced, an opinion which is by no means held in common at the present time, and yet there are localities where it has certainly proved advantageous. Occasionally, a plant will be cut off. There can be no doubt, however, that such disking, when necessary, does tend to clean the land and also to strengthen growth in the alfalfa crop, on the principle that cultivation which does not seriously disturb growing plants is always helpful to them. The frequency of such diskings will depend on the needs of the crop. Some advocate disking every spring, some every other spring, and some not at all. That plan which disks the ground only when it is necessary to keep the weeds at bay would seem to be the most sensible. This would mean that sometimes, as where crab grass has a firm hold, disking may be necessary at least for a time every spring. In other instances it would be necessary only every second or third season, and in yet other instances not at all. However, some growers in dry areas advocate disking frequently, as, for instance, after some of the cuttings of the hay, and with a view to retain moisture. It is at least questionable, however, if disking so frequently would not soon tend to thin the plants too much, to say nothing of the labor while the work is being done.

The idea of stirring the surface soil in alfalfa fields is by no means new. In England the plan prevailed to some extent years ago of harrowing the fields in the autumn with heavy harrows until, when the process was completed, they would take on the appearance of the bare fallow for a time. In the Eastern States and in some parts of Canada the harrow is used instead of the disk, but usually the latter will do the work more effectively and with less cost. Frequently, when the disk has been used on alfalfa, it may also be advantageous to run a light harrow over the ground to smoothen the surface.

With a view to renovate the crop and increase the yields, in some sections, as in the Atlantic States, it has been recommended to top-dress alfalfa fields with farmyard manure every autumn. This, no doubt, would prove very effective, but it would also be very expensive, unless in the neighborhood of large cities. It would be impracticable without neglecting the needs of the other crops of the farm. In the mountain areas of the West, it has been found that the cost of fertilizing with farmyard manure is in the meantime greater than the increased production in the alfalfa is worth, but it may not be always thus, even on these rich lands. Some Eastern growers also apply more or less gypsum. This is generally sown over the fields after the crop has begun to grow in the spring.

Renovating alfalfa fields is much more easily and effectively done, as would naturally be expected, in areas where conditions are highly favorable to its growth than where these are only moderately favorable. In some of the mountain valleys instances have occurred in which alfalfa fields have been plowed and sown with oats, with a result, first that a good crop of oats was reaped, and second, that fairly good crops of alfalfa were harvested the following season without re-sowing the field.

Sources of Injury to Alfalfa.—Chief among the sources of injury to alfalfa, after the plants have become established, are frost in saturated ground, ice, floods, grasshoppers, gophers, dodder, and pasturing by live stock in the late autumn or winter. When it happens that two or three of these act in conjunction, the injury following is just so much more rapid and complete. As has been intimated, where water is excessive, in a climate which in winter or spring is characterized by alternations of freezing and thawing, the plants will either have the roots snapped asunder, or they will be gradually raised out of the ground. This will only happen in soil with a subsoil more retentive than is compatible with well-doing of the highest order in the plants. The danger from this source is greatest during the first winter after sowing the plants, as then the roots are not really established. The only remedy for such a contingency is the draining of the land.

Some reference has also been made to injury done through ice, where it collects in low places in land. The destructiveness of the ice depends on its thickness and its nearness to the ground. When it rests upon the ground for any considerable time the plants die. If, however, water intervenes, the plants may live when the submergence is for a limited time. One instance is on record in Onondaga County in New York State, in which alfalfa survived submergence for a considerable period under a thin sheet of water covered by three inches of ice, but when growth came it was for a time less vigorous than normal.