1919] Pendleton: A Study of Soil Types 375 



Soil Surveying in the United States. — In a brief way, it has been 

 shown how there arose the different systems of soil classification. 

 Only a few typical systems of classifications, and something of the 

 reasons for the divergences, have been mentioned. 17 Probably the one 

 agency that has carried on the most extensive soil classification and 

 mapping is the Bureau of Soils of the United States Department of 

 Agriculture. It is now proposed to discuss and in a measure criticize 

 the work of the Bureau of Soils, the one organization that has, more 

 than any other, succeeded in applying a detailed system of soil classi- 

 fication over extensive areas. 



The problems that the Bureau had to face during its early exist- 

 ence were special studies of the soils of certain crops, especially of the 

 tobacco districts. 18 Later the soil utilization work of the Bureau of 

 Soils was transferred to other branches of the Department of Agri- 

 culture, leaving as the main task for the Bureau the systematic classi- 

 fication and mapping of the soils of the United States. 



Coffey 10 has so well discussed the present day conceptions of the 

 bases for the classification of soils, that it does not seem necessary to 

 repeat any portion of that excellent statement here. He showed that 

 the Bureau of Soils, in its method of classifying soils, uses a combina- 

 tion of a number of systems. This matter is dealt with more in detail 

 in an article by Coffey, 20 and the Report of the Committee on Soil 

 Classification of the American Society of Agronomy. 21 The question 

 often arises as to the validity of making the close distinctions regard- 

 ing color, texture, geologic origin, etc., and is one which should be 

 dealt with in order to render less empirical the nature of most of the 

 criteria which are used at present. See the Report of the Committee 

 on Soil Classification and Mapping. 22 



Because of different views regarding soils and soil fertility from 

 those held by the Bureau of Soils, the Illinois Agricultural Experi- 

 ment Station has undertaken a soil survey and classification, under the 

 direction of Dr. C. G. Hopkins, which is independent of the Bureau 



17 See Coffey's excellent treatment of the soil survey work in this country. 

 The Development of Soil Survey Work in the United States with a Brief Reference 

 to Foreign Countries, Proc. Amer. Soc. Agron., vol. 3 (1911), pp. 115-29. 



18 Whitney, Extension and Practical Application of Soil Surveys, Off. Exp. 

 Sta., Bull. 142 (1903), pp. 111-12; The Purpose of a Soil Survey, U. S. Dept. 

 Agr., Yearbook, 1901, pp. 117-32. 



19 A Study of the Soils of the United States, U. S. Bur. Soils, Bull. 85 (1912), 

 pp. 24-38. 



20 Jour. Amer. Soc. Agron., vol. 8 (1916), pp. 239-43. 

 2i Ibid., vol. 6 (1914), pp. 284-88. 



22 Ibid., vol. 8 (1916), pp. 387-90. 



