CROP ROTATION AND IRRIGATION 111 



Before the twentieth century, American agriculture con- 

 sisted 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 wa^ 

 to seek new land, or to give the land a rest from production. 

 Reports from thousands of correspondents show that little sys- 

 tematic 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 crop- 

 ping this grain on the same land. The most skilled farmers were 

 unanimous in recommending rotation of crops. The most gener- 

 ally 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 disap- 

 peared entirely. One-crop or two-crop production was charac- 

 teristic 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 which 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 cultiva- 

 tion alone was not sufficient to produce the best crops, and 

 1 Yearbook U. S. Dept. Agr., 1902, p. 520. 



