EXPERIMENT STATION BULLETINS. 



597 



TABLE 7.-QUANTITIES OF MAGNESIUM IN SOIL EXTRACTS IN PARTS PER MILLION ON SOILS. 



(a) 1st leachin^s — -2 day period. 



(b) 2nd leachings— 15 day period. 



All the treatments increased the quantities of Mg in the extracts 

 from the first leachings except Ca3(P04)2 which showed little change. 

 Results from the second leachings vary considerably and may be in- 

 fluenced somewhat by Mg in the acid phosphate, hydrated lime, and 

 CaCOg. The phosphates were not examined for Mg. 



T.ABLE 8.— QUANTITIES OF SODIUM IN SOIL EXTR.ACTS IN PARTS PER MILLION ON SOILS. 



Extracts from the treated soils contain more Na than those from 

 the checks excepting soil No. 3b with CaSO^ treatment, and the first 

 leachings on soils Nos. 1, 3 and 4. It is remarkable that the result on 

 Na and Mg from the Gag (1*04)0 treatments closely correlate. Consider- 

 able quantities of Na are reclaimed in the second leachings from the 

 NaCl and NaNOy treatments, indicating a continued solubility of this 

 element. 



TABLE 9.— QUANTITIES OF POTASSIUM IN SOIL EXTRACTS IN P.\RTS PER MILLION ON SOILS. 



(a) 1st leachings — 2 day period. 



(b) 2nd leachings — 15 day period. 



