EXPERiMENf STATION BULLETINS. 



327 



(B) Alkaline and acid sandy loam soils treated with NaCl Solution, Washed, then treated separately 



with KCl, CaCli and MgCli solutions. 



(C) Alkaline and acid sandy loam soils treated with MyCli solution, washed and then treated separately 



with KCl, NaCl and CaCli solution. 



Results in Table 6 show the reaction to be reversible in all cases studied^ 

 and the gram equivalent ratios closely approached without considering iron 

 and aluminum present as chlorides. In (b) portion of the table are shown 

 some results from determinations of potassium after the CaCh and MgCl2 

 retreatments. These quantities of potassium are about the same magnitude 

 as could be expected from solubility effects varying from about four to nine 

 parts per million of solution, and it is assumed that potassium plays an 

 unimportant part in these fixation processes. Another very important 

 relationship is also shown by this experiment in that after each preliminary 

 treatment the several cations used were fixed by the soils in nearly equivalent 

 quantities. In this connection it should be remembered that not all of the 

 soil calcium or magnesium in a condition to react would be removed by the 

 preliminary salt treatments although all of the soJutions used were equal in 

 concentration. 



CONCLUSIONS CONCERNING THE NEUTRAL SALT TREATMENTS 



The principal points observed in this investigation with the neutral salts 

 may be briefly summarized as follows: (1) All the soils, except the medium 

 sand containing limestone and in the case of calcium, precipitated the cations 

 of the neutral salts used and held them fixed in the soil mass. (2) The anions 

 of the neutral salts were not fixed to any great extent by the soils. (3) Fix- 

 ation of cations was accompanied by a closely equivalent liberation of other 

 soil elements particularly calcium and magnesium and the other elements 

 artifically fixed in the soils. (4) The fixation of potassium from KCl by 



