Fig. 9. Sweet Clover (Melilotus alba)
Tennessee Experiment Station
The uses of the plants are at least three. It has some value as a food for live stock. It has much value as a fertilizer. It has probably even more value as a food for bees. It has also been used in binding soils. Its value as a food for stock has probably been overestimated. It is bitter, notwithstanding the fragrant odor that emanates from it; hence, it is not relished by stock, insomuch that they will not eat it when they can get other food that is more palatable. As hay, it is hard to cure and of doubtful palatability when cured. As a fertilizer, its value does not seem to have been sufficiently recognized, and the same is probably true of it as bee pasture, although many bee-keepers are alive to its great merit for such a use.
This plant does not seem to find much favor with many. The United States Department of Agriculture has spoken of it as a "weedy biennial, concerning which extravagant claims have been made." The laws of some States proscribe it as a weed, and impose penalties directed against any who allow it to grow. Legislatures should be slow to class a legume as a weed, especially one that has much power to enrich soils. The author cherishes the opinion that this plant has a mission in the economy of agriculture and of considerable importance to farmers, especially in soils that are poor and worn, as soon as they come to understand it properly.
Distribution.—Sweet clover is probably indigenous to the semi-arid regions of Asia. The name Bokhara would seem to indicate as much, but it is also found in many parts of Europe, and if the facts were known, was doubtless brought from Europe to North America by the first settlers. For many decades it has been represented in many flower gardens in all parts of the country.
The plant will endure almost any amount of cold when it is once established. It has stood well the winters of Manitoba. It can also endure extreme summer heat, since it thrives well in some parts of Texas. It grows most vigorously where the rainfall is abundant, as in Western Oregon, and it makes a strong growth in the dry areas of Western Kansas and Nebraska.
Sweet clover will grow vigorously in some part or parts of every State in the Union. Of course, it has higher adaptation for some conditions than others. In some of the Central and Southern States, it has multiplied to such an extent without cultivation as to have assumed the character of a weed; hence, the legislation against it. When it is called to mind that this plant is a legume, and when the further fact is recognized that it may be used not only in enriching soils, but at the same time improving them mechanically, in addition to other benefits that it may be made to render, surely the enactments which prohibit its growth should be repealed in any State where these exist. In the Northern States, with a normal rainfall, the mission of this plant is likely to be circumscribed, for the reason that other legumes possessed of a much higher food value may be grown in these. In the Southern States, its mission will be more important, since it may be used in some of these with decided advantage in binding soils and in renovating them, even when too poor to produce a vigorous growth of cow peas. It is likely also that it may yet be made to render good service in the semi-arid country west of the Mississippi River, where other clovers cannot be grown.
Sweet clover will grow in all the provinces of Canada. For economic uses, however, it is not likely to grow to any great extent east of Lake Superior, or west of the Rocky Mountains. Other legumes more useful may be grown in these areas. But in the intervening wheat-growing region it is possible that it may come to be used for purposes of soil renovation.
Soils.—But little can be gleaned from American sources on this subject. Notwithstanding, it may be said with safety that it has greater power to grow on poor, worn and hard soils than any forage plant that has yet been introduced into America for economic uses.