1919] Pendleton: A Study of Soil Types 473 



in which the Hanford samples behave is not paralleled by any other 



type. There are certain ways in which the types are distinct: 



The nitrification of the soil's own nitrogen as compared with the 

 soil's action upon added nitrogen is in some degree separate for each 

 type. The San Joaquin samples nitrified their own nitrogen to a 

 greater degree than they did the nitrogen added In the soil. 



The relative nitrification of the several nitrogenous materials 

 (dried blood, cottonseed meal, ammonium sulfate) is in some measure 

 distinct for the several types. The Diablo, Altamont, and San Joaquin 

 types show ammonium sulphate to be nitrified the best, cottonseed meal 

 less, and dried blood still less. The Hanford samples show eottonseed 

 meal to give the highest percentage of nitrates, with dried blood Less, 

 and ammonium sulfate still less. 



When any one soil is compared through the three sets of deter- 

 minations there are no apparent similarities. The Hanford type 

 shows the greatest bacterial activity, while the San Joaquin shows 

 less, with the heavier types showing sometimes greater activity and 

 sometimes less than that of the San Joaquin. 



Work in Other States 



In connection with the original chemical work reported in this 

 paper, there should be mentioned the large amount of work done in a 

 number of states on the analysis of the types of soils as mapped by 

 the Bureau of Soils. Apparently, these analyses have been made 

 without any question as to the validity of the existing subdivisions 

 into types. The various analyses have been reported with some com- 

 ment, but that which does appear usually deals with the "adequacy" 

 or "inadequacy" of the plant food present. Blair and Jennings 36 

 present a large amount of data on chemical composition, some of 

 which on rearrangement show interesting relationships (table 85). 

 From the data the four series of soils with the largest number of 

 analyses were selected (see following table). Under each series there 

 are from 2 to 4 soil types, and from 2 to 6 analyses under each type. 

 The averages from each type are tabulated, also the averages of all 

 the types within the series. This is both for the strong acid extraction 

 and the fusion methods of analysis for significant plant food elements. 

 There are no doubts but that each series of soils shows characteristic 

 chemical peculiarities, peculiarities which are to a great extent con- 



36 The Mechanical and Chemical Composition of the Soils of the Sussex Area, 

 New Jersey, Geol. Surv. N. J., Bull. 10, 1910. 



