114 THE BOOK OF WHEAT 



wheat is greatest when the crop follows either corn or potatoes. 

 After these crops, placed in the order that they merit for pre- 

 paring the soil for wheat, come summer fallow, millet, vetch, 

 peas, wheat and oats. The more dry and unfavorable the sea- 

 son, the more important it was to introduce a cultivated crop 

 into the rotation. The best rotations included a perennial 

 grass, for which purpose brome grass is well adapted to North 

 Dakota. The rotations vary greatly in different states, and 

 soil, climate, and economic causes must determine which ro- 

 tations are most advantageous for any locality. Summer fal- 

 lowing is widely practiced on the Pacific coast, largely be- 

 cause there is practically no rotation feasible. 



Crop Rotations in Foreign Countries. In Canada, summer 

 fallowing is rapidly becoming general throughout the terri- 

 tories, where the profitable corn crops of the United States 

 cannot be grown on account of the latitude. The system of 

 agriculture most prevalent in Russia is the three-field system, 

 which is universally practiced in the center of the Russian 

 wheat belt. The usual sequence of crops is winter rye, spring 

 wheat and fallow. The arable land is divided into three cor- 

 responding parts. At a given time each part is in a different 

 stage of the system. Other crops are being introduced, and 

 this is lessening the area of fallow land. Among the private 

 land owners this signifies progress in agricultural methods. 

 Among the peasants it frequently signifies a harmful overwork- 

 ing of the land, the penalty of which is the drastic 

 retribution of greatly reduced yields. Another system, 

 still more primitive than the three-field one, is also 

 found in Russia, especially in the steppes of the 

 southeast, where the greatest extension of the wheat area 

 is taking place. By this system the land is tilled until it be- 

 comes exhausted. It is then allowed to lie fallow in order to 

 recover its fertility. This may require 10, 15, or even 30 

 years. In Archangel, Olonetz, Vologda, Viatka and Perm, the 

 forest must be cleared to prepare the new land for cultivation, 

 but in the southeastern provinces of Orenburg and Astrakhan, 

 in New Russia, Kherson and northern Caucasia, all that is re- 

 quired is to plow the land. As population grows, this wasteful 

 method of farming is being replaced by the three-field system. 

 Impoverishment of the land by continuous wheat cropping 



