322 



STATE BOARD OF AGRICULTURE. 



the quantities of potassium fixed and of calcium and SiOz dissolved by 0.2 

 N HCl in the non-carbonate soils. This general agreement of results leads 

 to the conclusion that soil calcium in some definite combination, probably 

 as silicate, may be largely responsible for the fixation of potassium from 

 KCl. A large number of chemical determinations have been made on these 

 soils and some of these results have been published, Spurway (8), but no 

 correlations with fixation of potassium from KCl except those shown in 

 Table 1 have been observed. There is no evidence of fixation of chlorine 

 from the KCl by the soils used in this experiment, and from this standpoint 

 the results are in agreement with those of many other investigators. Other 

 observations made in connection with the soils under discussion are as fol- 

 lows: (1) All the solutions were alkaline to red litmus paper except those 

 from soils No. 20 and 23. (2) The quantities of chlorine added to the so- 

 lutions were in excess of the quantities required to combine with the po- 

 tassium and calcium found by analysis, therefore, other chlorides were present 

 The reaction of the solutions indicates that iron or aluminum may not 

 have been present as chlorides at least in any appreciable quantities, and 

 the observed excess of chlorine may have been combined with sodium or 

 magnesium. The investigation was continued along similar lines in order 

 to settle this point if possible. 



The following experiments were limited to a smaller number of soils. Eight 

 soils were selected of four principal classes as follows: medium sand, sandy 

 loan, silt loam and clay loam including an alkaline and acid soil of each class. 

 All them alkaline soils were especially low in carbonate content except the 

 alkaline medium sand which contained carbonate from applied limestone. 

 These soils were dried in the air, passed through a 2 m.m. mesh sieve and 

 treated the same as the soils in the foregoing experiment. The soil classes 

 are indicated by their initials in the tables and the reaction refers to the lit- 

 mus paper test. Results are reported in Table 2. 



Fixation of Potassium from KCl and Liberation of Calcium and Magnesium 



from a Series of Alkaline and Acid Soils 



of Various Classes 



TABLE 2. — Fixation of potassium from KCl and quantities of soil elements found in the solutions 

 Potassium added 0.391 gm. Chlorine added 0.3646 gm. 



