8.

Grasses. The area devoted to pasture, hay and forage crops in the United States is greater than that devoted to any other single crop, and the product is of greater value than any other. This, however, includes some of the legumes which are

used for pasture, hay or forage.

There are about 3500 known species of true grasses, divided into about 300 genera. In the United States there are now known to be about 1380 species (1275 native and 105 introduced), divided among 165 genera (140 native and 25 introduced). W. J. Beal has described 809 native species and 103 exotic species.1

Lamson-Scribner gives the number of the best known and most valuable grasses for different purposes as follows: thirtyeight hay grasses, thirty-five pasture grasses, fourteen lawn grasses, twenty-four grasses for wet lands, twenty grasses for embankments, nineteen grasses for holding shifting sands. In a number of instances the same grass occurs in two or more different classes.

The principal cultivated grasses for hay are timothy and red top, the latter being especially adapted to wet lands, while Kentucky blue grass in the northern and Bermuda grass in the southern portions of the United States are the principal ones used for pastures and lawns.

9. Legumes for Hay and Pasture.-There are in the leguminous or pea family about 310 genera and about 5000 species. 1 Grasses of North America Vol. II, 1896.

There are about 250 species in the genus Trifolium and about fifty species in the genus Medicago: the two genera to which most of the plants used for hay and pasture belong. The census for 1900 reports the total yield of alfalfa hay in the United States as slightly larger than that of clover hay from about one-half the area. The clover species commonly used for hay are common red clover, mammoth red clover, alsike clover and crimson clover, of which the first occupies much the largest area. The vetch is grown somewhat, principally in the Pacific Coast States. The cowpea has become an important forage crop in the Southern States.

All the legumes above mentioned are grown more or less for pasturage. In addition, white or Dutch clover in the North and Japan clover in the South are distinctively pasture crops.

10. Legumes for Seeds.-The principal legumes raised for their seeds are field beans, field peas, cowpeas and peanuts. The soy bean is also attracting some attention as a seed crop as well as a forage crop. New York and Michigan are the leading states for the production of field beans; Michigan and Wisconsin for field peas; Georgia and South Carolina for cowpeas, and Virginia, North Carolina, Georgia and Alabama for peanuts.

11. Forage Crops.-In its best signification the word "forage" means any kind of food for animals, whether hay, straw, grain, roots, etc. Often, however, it is used to apply to the whole plant or portions of plants other than the secds, and thus to those foods containing a large proportion of cellulose or crude fiber.

In a more limited and technical sense a forage crop is an annual crop in which the whole plant is used for food. Thus maize is a cereal crop when the ears are husked and fed separately, while it is a forage crop when the whole plant is fed together either dried or ensilaged. Most of the plants used for forage are either grasses or legumes. Among the grasses the

principal forage crops are maize, sorghum or Kafir corn, millet oats, barley: among the legumes are cowpeas and soy beans. The rape plant is used somewhat as a forage crop.

12. Tubers. The only tuber of importance cultivated in the United States is the potato. Although the area devoted to the crop in this country is small compared to the total area under cultivation, yet the large yield of food per acre, the ease with which it is prepared for use, and the intensive character of the cultivation required, all conspire to make it an important crop. It is a relatively still more important crop in Europe, where the agriculture is more intensive.

The Jerusalem artichoke and chufa are also grown in a minor way for their tubers.

13. Roots. Generally speaking, the climatic conditions do not favor the production of root crops in the United States. In Great Britain especially, turnips, ruta-bagas and the various forms of the beet are grown largely for stock food. These crops are quite as important there as maize is in the United States. Canada also raises root crops somewhat abundantly. The sweet potato is raised extensively in the southern part of the United States and is an important article of diet in that section. Chicory and cassava are minor crops.

14. Sugar Plants.-The principal sugar plants are the sugar cane and the sugar beet. At the present time the latter furnishes more of the sugar of the world than the former. In the United States the most sugar is produced from the cane. The area over which sugar cane can be raised is not believed to be large, while the area over which beets can be successfully grown for the production of sugar is believed to be much more considerable. It seems probable, therefore, that the production of sugar from the beet will continue to increase until much the larger part of the sugar will come from this plant. Sorghum is, also, grown for the production of syrup, and hard maple forests are maintained both for the production of sugar and syrup.

15. Fiber Plants. The principal fiber plants of the United States are cotton, flax and hemp. In this country, however, flax is mostly grown for its seeds. The cotton plant is by far the most important fiber plant in the United States and is becoming increasingly the most important source of fiber either vegetable or animal in the world. Ramie, jute and sisal are also sources of fiber.

16. Stimulants.-Tobacco is of American origin and has been during the whole history of the United States an important industry and has constituted an important article of commerce. The tea plant is now being grown in a small way in South Carolina and, perhaps, elsewhere. Except in Porto Rico, Hawaii and other outlying possessions coffee has not been raised with commercial success.

17. Medicinal and Aromatic Plants.-Have not been cultivated largely. The following include the more important ones: mustard, mint (three species), tansy, pyrethrum (buhach), wormwood, valerian and ginseng.

18. Miscellaneous Crops.-Among the cultivated plants which are not included in the foregoing classification are broom corn, castor bean, hops, onions, teasel, taro, sunflower seeds, willows and pampa plumes.

19. The Staple Crops of the United States.-Are grass, including certain legumes, maize, wheat, oats and cotton. There has been a rapid increase in the cultivated acreage of the country and some changes in the proportion given to different crops, but there is little reason to believe that the time will soon come when these will not be the leading crops, at least so far as acreage is concerned. Almost every crop now grown on the farms of the United States had been grown to some extent before the Revolutionary War. Improvements in methods of culture, harvesting or in machinery for utilizing the crop have brought some crops into greater relative importance. This has been notice

ably true of cotton and it is much to be hoped it may be true of sugar beets and alfalfa.

20. Character of Field Crops.-Prior to the discovery of America the field crops of Europe were almost all sown broadcast. In the United States at the present time, more than half the field crops are raised by intercultural tillage. Maize, the white potato and the sweet potato are of American origin, while cotton was not largely raised until the beginning of the nineteenth century. The method of harvesting is also quite different. What are usually known as the small grains have been harvested with the sickle, cradle, reaper and self-binding harvester in successive years and afterwards flailed or threshed, while the crops grown by intercultural tillage have been in the past mostly gathered by hand. Root crops, the sugar beet and potatoes have been added to European agriculture within com paratively recent times.

21. The Beginnings of Plant Culture.—The six great cereals of the world have been cultivated so long that the wild type of each can with difficulty be recognized. Of these, wheat, barley and rice have been cultivated for more than four thousand years, while the cultivation of maize, oats and rye has not been traced much more than two thousand years.

22. The Possibility of Crop Production.-Depends mainly on climate and soil. Of these the climate is the more important, especially when large areas are considered. Manuring, culture or drainage may greatly modify the soil and make it fit for crops for which it was illy prepared. There is, however, a marked variation in the adaptability of different soils under the same climatic conditions. Certain soils are much better adapted to wheat and grass than for maize and potatoes, while other soils are much better adapted to maize and potatoes. Tobacco is a crop that is readily affected by the character of the soil. Plants, like animals, have great adaptability: they may become acclimated and do fairly well when neither soil nor climate is like