414 University of California Publications in Agricultural Sciences [Vol.3 



Table 28 — Potassium as K 2 



(J. Lawrence Smith Method) 



Hanford Fine Sandy 



Bacteriological Data 



The bacteriological work was not entirely satisfactory, partly be- 

 cause the conditions in one of the incubators were not all that might 

 be desired, and partly because of the refractory physical properties 

 of some of the soils. The Diablo and Altamont types, in all three 

 horizons, were very heavy and hard to mix and keep in even fair 

 physical condition. The San Joacpiin soils were predominantly of a 

 heavy texture in the B and C horizons, while the surface horizon 

 was light and the crumb structure was entirely lost if even a small 

 excess of water was added to the culture. 



Ammoxification 



There are very marked differences between the various types in 

 this determination, though the samples in a given type vary among 

 themselves to a large extent. 



Diablo clay adobe.— The highest ammonia production was about 

 three times the lowest, 7.7 mg. and 26 mg. In both this type and 

 the following, the B and C horizons follow the surface horizon quite 



