Late summer seeding, which permits consider able growth before winter and reduces danger from weeds to a minimum, is to be recommended if the moisture conditions are favorable, unless d anger from winter-killing (North) makes spring seeding necessary. In the North the plants should go into the winter with a considerable growth to hold snow to check freezing and heaving. Occasional mowings the first year, with the cutter-bar set high, hold the weeds in check and induce heavier stooling. It is not pas tured until after the first year and then but sparingly. In the West the stand lasts indefinitely, but in the East it is often run out by June-grass or Kentucky blue grass (Pea pratensis) and in the middle South by crab-grass. Disk ing with the disks set nearly straight is destructive to weeds and beneficial to alfalfa plants over two years old. The number of cuttings (one ton or more each) varies from two or three, where the summers are short, to six or seven where they are long. A normal yield is four to five tons per acre. It is cut when the first blooms appear, as later cut ting reduces the protein content and decreases the feeding value. Great care is necessary to pre vent the loss of leaves, which constitute as high as 63 per cent of the total protein of the plant. In the West it is usually raked into windrows a few hours after cutting, and as soon as cured sufficiently to prevent heating is hauled to the stack, or baler, on racks or hay sweeps, "go-devils" or " bullrakes." Hayforks (capa city 300 to 600 pounds) facil itate stacking and reduce the loss of leaves. In humid re gions the hay is cocked some what green from the wind rows, and when sufficiently cured is hauled on racks to the stack or barn.
Uses.
The feeding value of alfalfa depends on its high protein content and palatability. Alone it constitutes a main tenance ration, but it is gen erally fed in connection with starchy feeds. It is superior to clover hay in feeding value and may be substituted in part for bran in a dairy ration in the proportion of one and one-half pounds of alfalfa to one pound of bran.
It affords excellent pasture but must be grazed with caution, as cattle are likely to bloat, espe cially if turned on when hungry or when the alfalfa is wet.
It is well adapt ed for soiling pur poses, but is little used for silage unless continued rains prevent field curing.
In common with other leg umes it is a val uable soil-renova tor, although in the West it is rarely turned un der, the fields sometimes re maining in alfalfa fifty years.
The hay is sometimes ground and sold as alfalfa meal, either pure or mixed with prepared concen trates such as bran, corn chop and molasses. A considerable saving in freight rates is effected by this process, as the ordinary bales are too bulky to be shipped to the best advantage.
For ordinary shipment the hay is baled 110 cubic feet to the ton. For transoceanic shipment
double compressed bales are used (fifty-five to eighty-five cubic feet to the ton).
Causes of failure.
The causes of failure may be stated under three heads, as follows : (1) General. — Lack of at tention to soil requirements, preparation of ground and care the first year.
(2) Weeds.— Fox- tail and crab-grass in the Middle West, June-grass (Poa pratensis) in the North, Johnson grass and crab-grass in the South. The remedies for these are the use of clean land, frequent mow ings and occasional diskings.
(3) Inoculation.— La c k of inoculation (humid sections) is often a cause of failure. Har rowing in soil from an old alfalfa field at seeding time is the natural method and gener ally successful. The disadvan tages of this method lie in the difficulty of transporta tion (100 to 400 pounds per acre) and the danger of intro ducing weeds and plant dis eases. The commercial cul tures formerly on the market did not prove generally successful. With the improvement in methods of preparation and appli cation now being made by the United States De partment of Agriculture, the effectiveness of the artificial cultures promises to equal that of the soil transfer method without its disadvantages.
Enemies.
Dodder, or love-vine.--(Fig. 276.) This is a para sitic weed with golden thread-like stems and no leaves. It is especially troublesome in New York and Utah, being carried with the seed as an impu rity. The remedy is close cutting and careful removal of the stalks from the field. Burning the infested area and close pasturing frequently are successful.
Leaf-spot (Psesdspeziza medicaginis.)—(Fig. 277.) This is the most common disease and is especially noticeable when the plants are allowed to stand for seed. It is held in check by mowing, as the spore production is reduced and the growth of the plants made more vigorous.
Anthraenose (Colletotrichum trifolii, Bain).—This is a new disease, reported only from the humid states. It attacks the stems, producing well-defined purple patches. The plants turn yellow at the top and sometimes are killed over a considerable part of the field. Mowing the infested area and the application of a nitrate fertilizer probably are the best procedures. It is sometimes necessary to plow the infested area to prevent further spreading.
Root-rot (Ozonium sp.).—This disease is confined to the South and is the same as the cotton root-rot. It spreads in circular patches in the field. The only remedy is plowing under and keeping the land out of alfalfa until the spores are destroyed.
Animals.—Gophers (Geomys spp. and Thomomys spp.) and prairie dogs (Cynomys spp.) do considerable damage in the West, especially where it is impos sible to irrigate. Traps, carbon bisulfid, arsenic and strychnine are effective remedies.