ALFALFA IN WESTERN WASHINGTON

Transcription

1 Circular No. 18 Revised May, 1941 ALFALFA IN WESTERN WASHINGTON EXT'ENSION SERVICE State College of Washington PULLMAN, WASHINGTON Leonard Hegnauer, Extension Agronomist State College of Washington Fig. r. A W estern w ashington alfalfa field. Many trials with alfalfa have been made by farmers in Western Washington during past years. The trial stage is now practically over. There is much local information to guide those who wish to make a beginning in alfalfa growing. It is necessary t o use methods that are well established in order to reduce to a minimum the failures that tend to occur.

2 TEN ESSENTIALS IN ALFALFA GROWING ( 1) Choice of Soil: Not all land is sui ted to alfalfa. l\1 uch of it will not grow alfalfa. On some, alfalfa might live but will not be profitable. Soils must be selected with care for this crop. Silty and sandy bottom lands, having good depth, are best suited. The heavier types of upland soils, including clay loams,.are generally satisfactory; yields will not be as high as on the lowlands. On sandy uplands that dry out early in the season, and retain moisture poorly, yields are too low to be profitable. Peat soils are unsafe and should not be used. (2) Drainage: Land must be well drained for alfalfa. Conditions are most favorable if the water table can be held below the three foot level. The surface of the ground should have a regular even slope so that water has no chance to stand on the surface. If land does not have good under-drainage, it may be necessary to remove excess water through open ditches. Drained land maintains better moisture relations for alfalfa than land undrained. (3) Moisture Relations: The best possible relation between soil and moisture must be maintained. Alfalfa requires a good supply of moisture during the entire season, but at no time should the soil be filled with free water. If the soil remains filled with water even for a short time, plants begin to show signs of injury. Insufficient drainage is often responsible for a poor uneven stand which gradually dies out. A water-filled soil has no room for air. Much winter injury is caused by such a condition. ( 4) Fertilization: Alfalfa draws heavily upon the plant nutrients in the soil, and unless there is a good supply of these, satisfactory yields cannot be secured. Fertile lands, for that reason, have an advantage. Selection of soils where possible should be made on this basis. The right kind of fertilizers applied to even the best soils will give profitable returns. Animal manures can be used effectively in increasing soil fertility. With manure some plant nutrients are added, and the soil is put into good physical condition. To avoid the danger of increasing weeds, the manure should be applied to intertilled crops that precede alfalfa. Good tillage for the preceding crops cleans and prepares the ground for alfalfa. 2

3 The element, phosphorus, is particularly important for alfalfa. This may be applied in the form of a superphosphate, preferably with manure. If more is needed than was put on with manure for the preceding crops, it may be added alone at the time the seed bed for alfalfa is being made. It can also be applied as a topdressing on older stands. About 300 or 400 pounds of the 20 per cent superphosphate (this represents 60 and 80 pounds of phosphoric acid, respectively) or the equivalent of that in any other good form of phosphate fertilizer may be considered a good single application per acre. Fertilizers should always be distributed evenly. Even distribution makes for efficiency. After the fertilizers are on, the ground should be well disked. The field is then ready for the plow. More fertilizer, when needed, may be applied to the alfalfa later as top-dressing. Rotted manure and phosphate may be effect.ively used in this way. Late fall and winter applications are best. If alfalfa is to be seeded on land where lime is known to give profitable returns, then lime would have a special value for this crop. About two tons per acre of any one of the common forms of agricultural lime may be considered a good application. Lime should be worked into the seed bed during the early stages of its preparation but kept separate from superphosphate and manure if possible. ( 5) Seed Bed: A firm seed bed free from clods, grass, and weeds is necessary to get a uniform and full stand of alfalfa. Early plowing at medium depth helps in this preparation. Disking before plowing should be the rule. Disked ground crumbles and packs more readily than ground plowed without disking. Grasses and weeds are always a menace to alfalfa, and must be controlled. The cheapest and most effective control work can be done before sowing the seed. After the ground is plowed it should be disked or springtoothed and harrowed. Tillage should be shallow, but often enough to destroy all green growth and put the seed bed in the best condition. Previous cropping of the land is important. A cropping plan 111 which, for at least two years, cultivated crops such as corn or 3

4 potatoes were grown, helps to prepare the ground for alfalfa. Dur -ing this time the land can be well fertilized with manure and phosphate and the weeds kept under control. At the end of that time the ground should be clean. Never plow up pasture or meadow land for alfalfa. The ground cannot be put in fit condition and volunteer growth cannot be put under control. After the seed bed is made fine and clean, the ground is often too loose for alfalfa. It should then be rolled before seeding. Many times rolling after seeding is necessary. The corrugated type of roller is best for this purpose. The ground is never ready until good packing is assured. (6) Seed: Certified Grimm alfalfa seed of northern origin is well adapted to much of the area. Where there is danger of wilt, Ladak may be safer. Certification safeguards the origin, purity, germination and soundness of seed. Such protection is not furnished by seed not certified. This is extremely important to the grower. If the field is to be used for seed production, nothing but blue tag seed should be sown. If the seeding is to be used for hay only; lower grades (if certified) may be used. Seed verified as to origin ranks next to certified seed. Seed not certified is too apt to be unsafe. Seed is one of the least expensi,-e items in the cost of getting a stand of alfalfa. The difference in cost between good quality.and poor quality seed is not great. It is unwise, and often danger Dus to use low grade, inferior, impure, cheap seed, and this is particularly true if it is of an unsuited Yariety. It may prove expensive in the end. (7) Inoculation: Alfalfa must be well inoculated in order to get the best yields and hay of the highest feeding quality. Root nodules, indicating nitrogen gathering bacteria, should be present on all plants. No inoculation or even partial inoculation is often responsible for weak plants and weak stands that gradually dis.appear. It is unsafe to assume that the field may carry the necessary bacteria. It is also unsafe to rely upon such inoculation as might develop, from a poor beginning, as a stand grows older. The only safe way is to supply the bacteria in abundance at the time the seed is sown. Pure culture bacteria may be secured from the ag- 4

5 ronomy department of the State College of Washington. Sw.:h culture may be had at 25 cents for enough material to inoculate the seed to be sown on one acre. It is important that users follow absolutely the directions sent with the material. l (8) Seeding: The seed bed must be in excellent condition before seeding is done. Extra work can often be done while waiting for the soil to become warm. It is not possible to set a definite date for seeding. On ground supplied with moisture or where moisture can be retained through good tillage, seeding may be delayed safely until late in June. Such a late seeding has some advantages. On land that dries early and does not hold moisture well, earlier seeding must be done. However, in all cases a warm soil insures a better stand and faster growth. Fall seeding cannot be recommended. A stand of alfalfa is greatly dependent upon the condition of the seed bed as well as the time of seeding. It is impossible to get a good uniform stand on loose open soil, regardless of the amount of seed used. The seed bed must be made good enough so that around 15 pounds of seed per acre is all that is needed. The seed should not have more than one half inch of co\ ering, and in the case of heavier soils a little less is better. V..,T ellpacked soils make shallow seeding possible and safe. Perhaps the best job of seeding can be done with the drill. However, much broadcast seeding is done. The drill is better able to place the seed at uniform depth. If sown broadcast, the seed should be covered immediately to protect it from the sun. Half the seed should be sown, then the rest put on crosswise to insure evener seeding. A brush harrow or light spike harrow does good work in covering the seed. A roller may also be used effectively. Alfalfa should be sown alone. Some insist on using a nurse crop. This practice is not safe and cannot be recommended. When sown alone, alfalfa will probably produce some feed the first year which may easily offset the amount of forage that might be had from a nurse crop. The nurse crop too frequently interferes with securing a good alfalfa stand. (9) Management of Stand in the First Season: The work of the first summer has mainly to do with weed control. The new 5

6 seeding must be clipped to keep the weeds from producing seed, and from crowding the young alfalfa plants. Clipping must be done with caution. Never clip sooner nor oftener than is absolutely necessary. The alfalfa plants must be disturbed as little as possible while they are making their start. They must be giyen a chance to develop a strong root system in order to insure food reserves for later growth. Cut the weeds, when necessary, about six inches above the ground. Pasturing must be avoided. (10) Cultivation: After the alfalfa is established, cultivation becomes necessary to keep the stand clean. If the work was well done before seeding, little or no cultivating will be needed the first season. Tillage work must be done regularly, beginning with the second year. This should start in the spring before growth begins if the soil is dry enough to work. If the soil remains wet until after the alfalfa has made a good start, tillage should be delayed until after the first cutting has been removed. Work may be done, if required, after each cutting. Alfalfa may sometimes be cultivated to good advantage after the fall rains begin. No set rule can be laid down for time and frequency of cultivation, nor type of implement to use. The object of tillage is to keep the stand free from weeds and grass. In some cases it requires more work to do this than in others. For a young stand, a heavy smoothing harrow may do all the work necessary. Cross harrowing is more effective than harrowing in only one direction. If the ordinary harrow fails to control weed~ and grass, (this is usually the case as the stand becomes older) more severe tillage is required. The spring-tooth harrow is perhaps the best implement for destroying the sod and stirring the soil. This is particularly true when it is equipped with special alfalfa teeth. EYery alfalfa grower will find it to his advantage to use such a harrow regularly on the older stands. After the alfalfa has been well spring-toothed, the work needs to be finished with an ordinary harrow. This smooths the ground, exposes the grass roots to the sun, and makes weed killing more effective. Finally the roller cal). be used to advantage in repacking the loosened soil. This will help in keeping the hay free from dust. 6

7

8 Published and distributed in furtherance of the Act of May 8, 1914, by the State College of \Vashington, Extension Service, F. E. Balmer, Director, and U. S. Department of Agriculture cooperating.