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is augmented by the fact that the pioneer usually is farming a soil of such virgin fertility that for a number of years it will produce large crops in spite of extensive culture. Often, as has been the case in the United States from the very beginning, when the soil Has lost its fertility so that it will no longer yield standard crops, the farmer leaves the solution of the problem of its further profitable culture to others than himself by removing away from it to settle again upon virgin soil, and to repeat there his previous operations. While labor and all capital except land are higher in price in a new farming country, so little capital is required that its cost is usually below the cost of that required in the older country. In 1860 the United States was a half century behind England in intensive methods of farming, yet the cost of production was much lower for the American farmers than for the most scientific farmer of England, even if the latter paid nothing for the use of his land.1 If most of the members of a community are engaged in agriculture, the supply of agricultural products is not apt to fall below the home demand. Where such a large proportion of the people have an opportunity of producing at cost, home demand is not apt to raise the price greatly above the cost of production of older countries, and exportation is possible. Exportation involves the cost of transportation. Under normal conditions then, prices must always be lower at home than abroad before it will be profitable to export. As long as these conditions obtain, it will be impossible for prices of agricultural products in a new country (generally an exporting country) to be as high as those of an older country. High farming involves more expense than extensive farming, and consequently a larger capital is essential. But as prices cannot be so high in the newer community, and as capital is not so abundant, it follows directly and imperatively that farming cannot be of such a high and intensive grade. Unfortunately, however, as is so frequently the case with the recklessness of plenty, the most loose and careless methods of farming come in vogue, methods that are certain to exhaust the soil to such a degree within a limited number of years as to necessitate either improved methods of culture or its abandonment. While there may be extenuating circumstances in pioneer times which will 1 8th U. S. Census, Agriculture, p. vlil.
excuse extensive methods of farming when the future must be forgotten because of present necessities, when many of the advantages of an older society are wanting, and when the burden of public improvements perhaps falls comparatively more heavily, nevertheless such a course long pursued is not only short sighted and suicidal from the standpoint of the individual, but it is also unjust to the future.
When extensive methods of farming have once become customary, changes take place slowly, unless they are necessitated by the growth of population and the exhaustion of the land. These conditions continually repeat themselves in history, for the ancients were already well acquainted with intensive methods of farming.
Summer Fallows.—When land does not produce the usual crops, there is a wide practice of letting it rest one year. No crop is planted, but the land is generally cultivated. This almost invariably results in an increase of yield during succeeding years. It has been claimed that this gain is at the expense of heavy loss in humus matter and available plant food.1 Fallowing encourages the development of nitrates. One of its greatest advantages is that it enables the soil to store up moisture for the wheat crop of the following year.
Historical.—The farmers of ancient Egypt rotated crops. The same practice was followed in the time of Virgil, as well as the fallowing of land. The three-field system was not new in England in Norman times. It consisted of wheat the first year, barley or oats the second year, and fallow the third year. According to Gibbins crop rotation was not practiced in England in the beginning of the sixteenth century, but the triennial fallow was usual in the first half of the eighteenth century. It was known as the "Virgilian" way of farming. Clover and lucern were introduced in the eighteenth century, and brought a new rotation of crops that saved the wasted year during which land used to lie fallow. In the middle of the nineteenth century, rotations were practiced which brought a wheat crop every fourth or fifth year, or twice in 6 years. The Japanese sowed the wheat in rows, and cultivated vegetables between the rows at the same time, in addition to raising other crops before or after the wheat crop on the same ground during the same year.
1 N. D. Bui. 24. p. 73.
Before the twentieth century, American agriculture consisted mainly in raising cheap crops, and little attention was given to resulting effects upon the soil. After the soil was robbed of its fertility, various devices were resorted to in order to get a paying crop. The most common of these was to seek new land, or to give the land a rest from production. Reports from thousands of correspondents show that little systematic crop rotation "was practiced in the United States even as recently as 1902.1 At the close of the eighteenth century the deterioration of the soil became apparent, particularly in Virginia and Maryland, and as early as 1882 it was noticed that the yield of wheat was declining on account of continually cropping this grain on the same land. The most skilled farmers were unanimous in recommending rotation of crops. The most generally advised rotation gave one wheat crop in three years. Under the stress of hard conditions a true conception of the necessity of rotating crops gained a foothold and expanded into farm practice. As would be expected, the longer the occupation, the more developed is the crop rotation. In passing from the east to the west, the degree of rotation begins to diminish in Ohio, and by the time Kansas is reached, it has practically disappeared entirely. One-crop or two-crop production was characteristic of the first agriculture of the north central states.
On the Dalrymple farm of North Dakota wheat was grown continuously for about eighteen years, by which time the soil had been so impoverished that a system of crop rotation and summer fallow became necessary. Generally corn and barley are sown and cut early so that the land may be plowed in July before the wheat harvest. Considerable land is also barren summer-fallowed, in wnich case it is plowed twice during the summer. In Canada, experience with continuous cropping has been much the same as in the United States. Large areas in different parts of the early settled portions which once yielded fine crops of wheat have been abandoned to pasture and other purposes.
Experimentation.—In experiments in North Dakota, the plots which had been rotated with corn or potatoes yielded about twice as much as the best continuous wheat plot. Good cultivation alone was not sufficient to produce the best crops, and 1 Yearbook U. S. Dept. Agr., 1902, p. 520.
other crops gave a poorer yield on land that had been continuously sown in wheat. "Land which produced three crops of wheat and one cultivated crop in a period of four years, gave almost as much wheat and more profitable returns than did the land which produced four crops of wheat in succession."1 Experiments have been made in the continual culture of wheat on a certain piece of ground, there being no fertilizing of any kind, as, for example, the "experimental acre" in Kansas. This trial was begun in 1880, and by 1896 the yield was falling off. Permanent spots of diminished fertility had then appeared. Though they may have been due in part to surface-washing, partial exhausting was undoubtedly a factor.2
Historic experiments in growing wheat continuously without fertilizing have been carried on in England for over 50 years. "The yield has fallen to about 12 or 13 bushels to the acre, but for the past 20 years there has been little or no difference in the yield, except slight fluctuations due to seasonal conditions. So far as is known, the soil will produce 12 or 13 bushels to the acre annually for hundreds of years."*
The Crop Rotations of the United States now generally practiced in some typical counties of states leading or prominent in their geographical divisions, are given below:
Pennsylvania.—Corn, wheat two years, grass two years (York, Franklin, etc.). Corn, oats, wheat, grass three years (Chester, Westmoreland).
Minnesota.—Wheat two years, oats, wheat, flax (Marshall). Corn, wheat two years, oats (Lac qui Parle). Corn, wheat two years, grass two years (Ottertnll, Todd, etc.).
Washington.—Wheat, rest (Adams).
California.—Wheat, rest (Solano, San Joaquin, etc.).
Maryland.—Corn, wheat two years, grass two years (Montgomery, Frederick, Talbot, etc.). The rotation on dairy and stock farms includes wheat for only one year.
Oklahoma.—Wheat without rotation (Grant, Garfield, Kingfisher, etc.). Wheat, corn, (Dewey). Wheat three years, oats (Kay).
No crop, nor even any one class of crops, such as the cereals, should be continuously grown on a soil that will produce a variety of crops. On ordinary soils, cereal crops should be rotated every two to four years with a leguminous crop, such as clover or alfalfa. The North Dakota experiment station finds that wheat should have a good place in the rotation because it is a particular crop, and that the average yield of
1 N. D. Bui. 48, p. 735: Bui. 39, p. 458.
• Kan. Bui. 59 (1896), p. 90.
* Indus. Com., lOxlxxxviii.