mally 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 resowing 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.

Floods in warm weather are greatly injurious to alfalfa. The extent of the injury done increases with increase of depth in the waters of submergence, increase in stagnation in the waters, and increase in the duration of the period of overflow. Stagnant water sooner loses its dissolved nitrogen; hence, the plants cannot breathe normally. The

harm done, therefore, by floods in each case can only be known by waiting to see the results. These summer floods always harm the crops temporarily, and in many instance kill them outright. Occasional periods of overflow should not prevent the sowing of alfalfa on such lands, since on these it is usually not difficult to start a new crop, but the seed should not be sown on such lands when overflow occurs at such a season. When it occurs in cool weather and quickly subsides, it may be possible to grow paying crops of alfalfa.

In some areas grasshoppers are a real scourge in alfalfa fields. Because of the shade provided by the ground and the influence which this exerts in softening it, they are encouraged to deposit their eggs and remain so as to prove a source of trouble the following year. It has been found that through disking of the land both ways after sharp frosts have come is greatly effective in destroying the grasshopper eggs deposited in the soil. They are thus exposed to the action of the subsequent frosts and so perish. The disking has also tended to stimulate growth in the crop the following year. The eggs will not, of course, be all destroyed by such disking, but so large a percentage will, that the crop should be practically protected from serious injury, unless when grasshoppers come from elsewhere.

It would seem correct to say that gophers do more injury to alfalfa fields in certain areas of the West than comes to them from all other sources combined. They not only destroy the plants by feeding upon them, but they fill the soil with mounds, which