Ol 



UNIVERSITY OF CALIFORNIA PUBLICATIONS 



IN 



AGRICULTURAL SCIENCE 



Vol. 3, No. 12, pp. 369-498, 33 text-figs., pis. 43-74 June 30, 1919 



ARE SOILS MAPPED UNDER A GIVEN TYPE 



NAME BY THE BUREAU OF SOILS METHOD 



CLOSELY SIMILAR TO ONE ANOTHER? 



BY 

 ROBERT LARIMORE PENDLETON 



CONTENTS 



PAGE 



Foreword 369 



Introduction .' 370 



Need of a classification of soils 371 



Historical development of the classification of soils 371 



Plan of the present study 376 



Discussion of results '- J >7 7 



Mechanical analysis 380 



Chemical data 39;> 



Bacteriological data 41-1 



Greenhouse data 432 



General discussion 467 



Summary 481 



Appendices 483 



A. Methods and technique 483 



B. Soil sample locations 490 



FOR?] WORD 



It is due the author, as well as to the undersigned, that a few 

 words be said hy way of preparing the reader for what follows in this 

 paper. It will he observed, first, that the manuscript was. for an 

 unusually long time, in the printer's hands. Those who appreciate, 

 as few do today, the great rapidity with which the theories and the 

 methods in soil and plant study change, will readily catch the signifi- 

 cance of the foregoing sentence. Much of the work done by Mr. 

 Pendleton and some of the methods used may now properly be con- 

 sidered obsolete, or, conservatively speaking, at least obsolescent. 

 Nevertheless, I deem it of some importance to give the results obtained 

 in more or less detail, because of their historical value, and because -Mr. 





