Hay is the largest single crop produced in the United States. The total amount of hay and forage crops cannot be given, as large quantities are consumed by cattle in pastures, but the crop of 1918, after pasturage had been finished was 75,459,00o short tons, valued at $1,522,473,000. The great staple, cotton, was grown in the South before the Revolutionary War, but the invention of the cotton gin in 1792 by Eli Whitney caused cotton to become the most important crop of the southern tier of states. Before Whitney's invention seeds were removed from the cotton by hand or by a roller-mill. A slave could clean five pounds per day by hand, or sixty-five by the mill. The cotton-gin enabled a slave to clean 300 pounds per day and with improvement in the gin the amount was soon increased. At first most of the cotton was exported to England, but with the growth of the textile factories in New England, and later in the South, the domestic consumption of cotton increased and in 1918 only 40.58 per cent of the cotton crop was exported. The production of cotton for the year ending July 31, 1918, was 11,302,000 bales of 500 pounds each. Chiefly on account of conditions brought about by the war, the value of the crop of 1918 was more than twice the average value for recent years. Tobacco has been an important crop in many sections of the country since its early settlement, but unlike cotton, tobacco may be grown in the North, and Connecticut and Wisconsin are among the states producing considerable quantities of tobacco. Kentucky produced 427,500,000 pounds out of a total crop for 1918 of 1,340,019,000 pounds. North Carolina and Virginia are next in tobacco production. Tobacco is most exhausting to the soil and heavy fertilization or resort to new lands is necessary for its successful growth. Sugar-cane has been grown in several southern states, but only in Louisiana has it become of any great importance. From Louisiana cane there were produced in the year ending March, 1919, 546,862,400 pounds of sugar. The States of California, Colorado, Idaho, Michigan, Ohio, and Utah produced most of the sugar-beets, from which, in the year ending March 31, 1919, 1,510,128,000 pounds of sugar were made. In the year ending June 30, 1918, Porto Rico sent 672,937,334 pounds of sugar to the United States, and Hawaii sent 1,080,908,797 pounds. Americans are among the greatest of sugar consumers, averaging about 80 pounds a year per capita; 51 per cent of the sugar consumed in 1918 was imported from foreign countries. Intensive and Extensive Cultivation.-Where land is expensive as compared to labor and fertilizers, it pays to invest a large amount per acre in labor and fertilizers. This is known as intensive agriculture. In Europe intensive agriculture is the rule. The market gardens near the large American cities also are examples of intensive agriculture. In America there is a larger use of machinery than in Europe, because labor here is expensive as compared with machinery. Where land is cheap and labor and fertilizers are expensive, it pays better to spread an investment of capital and labor over a large area of land; this is extensive agriculture. Whether extensive or intensive agriculture is employed depends wholly upon the comparative expense of land, labor, and capital. Though the wheat lands of the Red River Valley of North Dakota are not surpassed in fertility by any wheat lands in the world, a small amount of labor and capital is expended per acre and as a result land much inferior in Europe yields a larger crop per acre than the Dakota lands. However, the cost per bushel is less in North Dakota than in any European country. The Law of Diminishing Returns in Agriculture.-With additional investments of labor and capital upon a given area of land, the point will be reached when returns will not be proportionate with the increased investments. For a time there will be increased returns, until the point of maximum return is reached and then returns diminish in proportion to the investment, and it pays better to take up another piece of land than to cultivate more extensively the old. The following example in the production of potatoes illustrates the law of diminishing returns. |