CHAPTER 1 



Soil Classification and Crop Adaptation 



The thin layer of the earth's surface known as the "soil and subsoil'' 

 supports all vegetation and makes it possible for the earth to sustain a 

 highly developed life. The prosperity and degree of civilization of a 

 people depend in a large measure on the productivity and utilization of 

 this thin surface layer of the earth's crust. From it come the food supply 

 and the materials for clothing and to a considerable extent the materials 

 for housing of mankind. 



Soils are Permanent. — The soil is indestructible, and according to the 

 great laws of nature, it should be capable of supporting generation after 

 generation of men each living on a slightly higher plane than the pre- 

 ceding. This necessitates a system of agriculture that is permanent, 

 and one that will foster and maintain the productivity of the soil. Each 

 man who owns and cultivates land owes it to his fellow-men to so cultivate 

 and fertilize the soil that it will be left to his successor in as good or even 

 better condition than it was during his occupation. In return, his fellow- 

 men should make it possible for him to secure a living without resorting 

 to soil robbery. A faulty system of soil management that permits a 

 decline in soil productivity will ultimately be just as injurious to the men 

 indirectly dependent upon the soil as it is to those actually living on the 

 land. 



The soils of the United States and Canada are a great asset, and 

 one over which man has relatively large control. Intimately associated 

 with this great asset are two other resources, namely, the atmosphere 

 that envelops the earth and the sunshine that reaches it. Little can 

 be done, however, to control these assets, but with the surface of the earth 

 man can do much as he pleases. 



What Farmers Should Know. — Every farmer should have a thorough 

 knowledge of the soil on his own farm. In this and following chapters, 

 the soil and its properties as related to the business of farming will be 

 discussed chiefly from the standpoint of the farmer. The practical farmer 

 expects cash compensation for the intelligent care he gives to his land. 

 He should be able to distinguish between the essentials and non-essentials 

 in the science of the soil. He should know that all soils may be made 

 productive, but this cannot always be done at a profit. Soils on which 

 men, by the exercise of intelligence and reasonable industry, cannot 

 make more than a meager living, should not be cultivated. They should 

 revert to nature or be devoted to forestry. There is some land that has 

 been cleared of its virgin growth and come under the plow that should 

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