H. S. Coe

“ On account of the low germination of much of the sweet-clover seed offered for sale it is very important that seed be tested for germination before planting. Low germination usually is due to the fact that many of the seeds remain hard after they have been in the germinator or soil for a month or more. The seed coats of hard sweet-clover seeds become permeable to water very slowly, if at all, in storage. The germination of such seeds is greatly increased, however, when they are subjected for a time to alternating temperatures, such as freezing and thawing. ”

“ Good success has been attained by merely broadcasting the seed on sandy soil and scratching it in with a harrow. Such a seed bed appears to be ideal when the seed can be covered sufficiently to insure plenty of moisture. It must be remembered that young sweet-clover plants are not drought resistant and that every precaution should be taken in seasons of drought or on laud which drought affects badly to so prepare the seed bed that the largest quantity of moisture will be conserved. ”

“ A comparatively new method which has given successful results calls for dampening each bushel of seed and spreading it on a cloth, paper, or cement floor, where half a gallon of throughly inoculated soil from sweet-clover or alfalfa plants may be sifted over it. Some people prefer to add a trace of glue or sugar to water, so that more of the soil will adhere to the seed, although some soil will remain on the seed if the glue or sugar is not used. When only this quantity of soil is used it should be collected from around the roots of sweet-clover plants which are abundantly inoculated. ”

“ Sweet clover will do well on many soils which are not fertile enough to grow red clover or alfalfa, and it is on these soils that it will prove most valuable. Like many other plants, it makes its best growth on fertile soils rich in calcium carbonate, although it will make sufficient growth on poor soils which are not acid to warrant planting it on them. Many hilly pastures may profitably be seeded to sweet clover. It will not only make a valuable addition to the forage of these pastures but will improve the soil so that grasses will grow more abundantly. ”

“ A pure culture of the proper kind of bacteria should be applied to the seeds in such a way that they will all be moistened. The seed should then be permitted to dry in a shady or dark place and should be planted as soon as possible after it is dry. Drying may be facilitated by adding dry, sifted soil, preferably from the field where the seed is to be sown. Inoculating organisms very often die within a week after the seed is inoculated. It is highly desirable, therefore that the inoculation be made the day the seed is sown. Inoculated seed never should be dried in the sun. ”

“ Ordinarily it is not necessary to inoculate sweet clover when it is to be planted on land where alfalfa, bur-clover, or black medic thrives, because the same strain of inoculating germs inoculates all of these plants. However, when this closer is to be planted on land where none of the plants inoculated by this strain of the organism have been grown, inoculation should be provided. In localities where sweet clover or other plants inoculated by the same strain of bacteria thrive, the early growth has at times been made much more vigorous by inoculating the soil or seed thoroughly. ”

“ Yields of sweet-clover hay have been increased as much as 2 tons per acre from applications of barnyard manure. Such an increased yield would be equal approximately to 8 tons of green-manure. Some people may consider it poor farm practice to apply manure to such crops as sweet clover, but it is very probable that the cumulative effect of the increased yields of the following crops, especially on soils low in organic matter, will be greater than if the manure is applied to other crops. Heavy applications of manure to the preceding crop should also greatly benefit sweet clover. ”

“ The famous Cruyere cheese of Switzerland owes its flavor to yellow sweet clover. In Germany it has given very good results when used as a green-manure, while in parts of Russian Poland and Austria-Hungary it is grown as a green-manure, pasturage, and hay crop on poor soils. This plant is used for forage and as a soil-improving crop in the central provinces of India, while sour clover, commonly referred to as Melilotus parviflora, is credited with furnishing 75 per cent of the feed for the cattle of King Island, Tasmania, which produce the best beef and butter sold on the Tasmania market. ”

“ When sweet-clover plants are not inoculated they must depend upon the available nitrogen in the soil for their supply, and as the crop is grown for the most part on soils low in nitrogen the plants can not be expected to make more than a small growth. ”

“ It is a common practice in many sections to pasture the crop until about June 10, when the stock is removed and the plants are permitted to mature seed. If the plants have not been grazed closely they should be clipped at this time, so that the seed crop will ripen more evenly. Sweet clover may be pastured during the entire second season's growth, provided sufficient stock is kept on the field to prevent the growth from becoming woody. If the plants become coarse the pasture may be clipped, leaving an 8-inch stubble, so as to induce a new growth which will be more palatable. ”

“ No data have been secured on winter seeding in those portions of the United States where open winters do not occur. It is probable that in those sections the winters are sufficiently cold to prevent germination before spring. Good results may be obtained by winter seeding, but as usually no trouble is experienced in those sections in obtaining a stand by seeding as soon as the soil can be worked in the spring, it is strongly recommended that seeding be done with hulled seed, which germinates well at this time of the year. ”

“ After the drainage of water-logged land on which there is a surface accumulation of alkali, it is the common practice in parts of Utah to grow sweet clover for several years before planting alfalfa. It is often stated that alkali land will grow less tolerant crops after sweet clover has been grown on it for a few years. The long roots will open up the subsoil and cause better drainage, thereby affording an excellent means for removing the salts from the soil, as they are readily soluble in water. ”

“ In those sections of the country where the moisture supply is limited, sweet clover should be sown without a nurse crop. Failure to obtain a stand is more likely to occur when the seed is sown with grain than when it is sown alone, because during dry weather, which is likely to occur when the grain is maturing, the supply of moisture in the soil is apt to be insufficient for both crops. ”

“ Arny and Thatcher, at the Minnesota Agricultural Experiment Station, obtained 10 times as much dry matter in the tops and seven times as much in the roots of sweet-clover plants which had been grown on thoroughly inoculated soil as from plants Which had been grown on soil not inoculated. Moreover, the plants grown on the inoculated soil contained 117 pounds more nitrogen to the acre than those grown on the uninoculated soil. ”

“ The plants thrive on newly exposed heavy clay soils and upon steep embankments where little else will grow. Sweet clover is more tolerant of poor drainage, overflow, and seepage conditions than alfalfa. In irrigated sections, especially where the reservoir system is in use, large bodies of land are likely to become useless for the growth of alfalfa because of the rising of the water table. On such areas sweet clover will make a vigorous growth. However, maximum growth is to be expected only on well-drained soil. ”

“ Owing to the fact that sweet clover thrives on the barren Selma chalk (rotten-limestone) hills of Alabama and Mississippi and grows abundantly on worn-out, abandoned land in north-central Kentucky, it is often assumed that it will grow on soils too depleted in plant food to produce other crops. These regions represent soils which have become exhausted primarily in nitrogen and humus as the result of continuous cropping with nonleguminous plants. ”

“ In hulling seed the rasps or concaves of the machines scratch the seed coats sufficiently to permit water to penetrate them, so that the germination is greatly increased. Apparently there is no reason why southern-grown seed when it is properly hulled should not germinate as well as northern-grown seed. ”

“ It is difficult for the average person to distinguish between the different species of sweet clover from an examination of the seeds or seed pods only. The differences are indicated in figure 1. Where there is a question as to the identity of a sample of seed it should be sent to a State agricultural experiment station or to one of the seed laboratories of the United States Department of Agriculture for identification. ”

“ On account of the finer stems of yellow sweet clover it is preferred in some localities for hay, but since it does not produce as much forage as white sweet clover and there is much less demand for the seed, it constitutes only a very small percentage of the total acreage. The much larger root growth of the white species, as illustrated in figure 5, is desirable because of the additional quantity of hummus added to the soil. ”

“ Sweet clover thrives in the more humid parts of the country, as well as in the semiarid regions where the rainfall is but three-fifths of that required for the normal growth of such crops as red clover and timothy. In the semiarid regions of the West sweet clover has proved to be somewhat more drought resistant than alfalfa. ”

“ When this practice is followed little harm can be done by the light. To facilitate even scattering, the soil may be mixed thoroughly with two or three times its weight of other soil, preferably from the field where the sweet clover is to be sown. ”

“ Good success has been obtained by drying in a dark place soil containing the inoculating germs, sifting it, and running it through the fertilizer compartment of a grain drill. When this method is employed it is not necessary to use as much soil as when it is scattered broadcast. ”

“ The drill may be tested by blocking it up, so that the geared wheel is off the ground, and this wheel may be turned a sufficient number of times to establish a definite portion of an acre. The seed that runs through can then be weighed and the rate per acre determined. The rate may be determined more accurately by plugging up the grain tubes or by tying a small sack on each tube and pulling the drill for a specific distance over the field to be sown. The jar of the drill will cause it to drop more seed than when it is blocked up and run by hand. ”

“ Some of these soils contain sufficient phosphorus and potassium for fair crop production, although this supply may be in such a condition that it will not become available fast enough to supply the needs of most crops. ”

“ In the fall of 1914 the hay cut from the limed areas exceeded that from the areas with a low lime requirement by 600 pounds per acre and exceeded that from the areas of high lime requirement by 4,000 pounds per acre. In July, 1915, the increase in hay yield on the limed areas over that from the areas with a low and with a high lime requirement was 2,300 and 9,400 pounds per acre, respectively. The area of high lime requirement returned a small yield in 1914 and no hay in 1915. ”

“ While sweet clover is to be found growing in many countries and on all the continents of the world, it is native to temperate Europe and Asia as far east as Tibet. It is grown to a limited extent in « 11 » England, while in the eastern part of Scotland a small quantity is considered valuable in hay on account of its agreeable odor. ”