EXPERIMENT STATION BULLETINS. 669 



THE SOI>UBLE CONTENT OF UNCROPPED FIELD SOILS AT DIFFERENT SEASONS 



OF THE YEAR. 



It was i)ointe(l oiil in an earlier part of this paper that temperature 

 and moisture content have an appreciable effect on the solnbility of the 

 soil constitnents. In view of this it may be expected tliat the soluble 

 salt content oi' lield soils will vai-y somewhat with the seasonable varia- 

 tions of climate. In ordei- to obtain inrormation concerning the relative 

 magnitu<le of such vai-iations, if they occur, samples were obtained Iroiii 

 several soil classes at different periods during the growing season. Hoth 

 the vii'gin soils and soils from adjacent fields were sampled. 



To obviate the effect of plant growth small areas were kept free from 

 vegetation and the samples taken from these areas. Owing to a mis- 

 understanding the surface quarter inch of soil was removed before sam- 

 ])ling and then sections taken to a depth of six and twelve inches, respec- 

 tively. The results thus far obtained are presented in tables ;>(), 'M, 82, 

 33, and the diagramatic ])resentation of the data is set forth in the accom- 

 panying graphs. 



