598 



STATE BOARD OF AGRICULTURE. 



Except ill case of KCl the tendency of the treatments was to depress 

 the solubility of K, Ca3(P04)2 and CaCOg showing the greatest effect. 

 Slight increases may be observed in case of the CaSO^ treatment on soils 

 Nos. la, 2a, and 4a, and the hydrated lime treatment on soil No. 4a, but 

 they are so small as to be practically negligible. The solubility of K 

 from the KCl treatment is continued in appreciable quantities in the 

 second leachings. 



TABLE 10.— QUANTITIES OF IRON OXID IN SOIL EXTRACTS IN PARTS PER MILLION ON SOILS. 



(a) 1st leachings — 2 day period. ' 



(b) 2nd leachings — 15 day period. 



Quantities of Fe in the extracts estimated at Fe^Oa vary considerably. 

 However, some interesting conclusions may be drawn. Ca(H2P04)2 

 greatly increased the quantities of Fe going into solution, as did NaCl 

 but to a lesser extent. In the second leachings from all the other treat- 

 ments excepting KCl there are increased quantities of Fe. Apparently 

 the Fe of the soils is more soluble when the soluble products of these 

 treatments are removed; however, the time factor may apply here. The 

 more immediate effect of KCl seems to be greater than its residuary 

 effect. 



TABLE 11.— QUANTITIES OF ALUMINUM OXID IN SOIL EXTRACTS IN PARTS PER MILLION ON SOILS. 



(a) 1st leachings — 2 day period. 



(b) 2nd leachings — 15 day period. 



The general tendency of all the treatments was to increase the quan- 

 tities of soluble Al in the soils. Ca(H2P04)2, CaCO.., and acid phosphate 

 having the greatest effect. The effect of hydrated lime was to increase 

 the amounts of Al in the first leachings and to decrease them in the 

 second leachings, while CaSO., NaN03, and Ca3(POj2 l^iid to the oppo- 

 site effect. 



