334 



STATE BOARD OF AGRICULTURE. 



TABLE 11. — Fixation from KiC-zOi and FeCh. 



Potassium added 0.3910 gm. C2O1 added 0.44 gm. 

 Iron added 0.3910 gm. (as FeaOs) 



In case of the K2C2O4 treatments, Table 11, the results agree generally 

 with those obtained from K3PO4 and KC2H.,02 with respect to order and 

 quantities of potassium fixed. CoO^-ions fixed were not equivalent in amounts 

 to the potassium ions fixed. Calcium was found to be present only in traces 

 in these extracts. 



FeCla was used as an eJcample of an acid hydrolyzing salt and the quantity 

 of iron fixed was found closely proportional to the calcium found in the 

 extracts, except in case of the alkaline medium sand soil which contains lime- 

 stone in considerable quantities. Magnesium was not determined but 

 probably enters into the reaction. The extracts from these treatments 

 were acid and the effects, in general seem to have l)een a neutralization of 

 the acid salt. In this experiment an attempt was made to determine if 

 the iron fixed in the sandy loam soils could be replaced by a KCl treatment 

 after washing the FeCU treated soils with water. Results of these determ- 

 inations are given in the portion of Table 11 headed "KCl after washing". 

 It may be observed that the potassium fixation was greatly reduced as com- 

 pared with the results from fixation of potassium from KCl in the untreated 

 soils, an equal quantity of KCl being used in the solutions. Also, calcium 

 and magnesium found in the solutions were more than equivalent in quanti- 

 ties to the potassium fixed. From these considerations it is doubtful if the 

 iron fixed from the FeCla treatments may be replaced and probably exists 

 in the soils in the hydroxide form. The effect of lowering the potassium 

 fixation was similar to that produced by HCl. 



Effects produced by treating soils with hydrolyzing salts are similar in 

 some respects to those obtained by treating with neutral salts and dissimilar 

 in other respects. The alkaline soils with few exceptions fixed a greater 

 quantity of the basic radicals of all the salts used as well as the acid radicals 

 that form insoluble compounds with calcium or magnesium. An explanation 

 of the exceptions was given in case of the neutral salts trea,tments. The 

 same explanation may apply to the exceptions noted in the hydrolyzing 

 salts treatments. The acid clay loam soil fixed more potassium and less 



