21 



In each case 1 reprasants tha amallast amount of th© 

 raspactiv© eonstituant found. 



In another tabla (p. ) is ^ive»n tha ran/i® found in 

 aight coil typ«sis, 



NO3 varies in the proportion of 1 to 5.8 

 ?fP04 ** " " " " i '^ 2.8 



K " " " " •• i w 2.4 

 Cameron and Bail (Bu. Soils 30, 67) state that 

 '''analyses oi & number of ©xtracts obtained from several typas 

 of soil of widely different origin and compoeition have 

 yiaidad «n average for potassium (K'^ of 27.3 j)arts, and for 

 phosphoric acid (PO4) 8.5 parts p&r ailiion aoiution. The 

 approximate uniformity of the individual r = suitB makti'S it 

 appear improbabla that a further accumulation of data would 

 change these averagf^ figures raat-sriaily. 



In August and September (Eu. Soils 26, 49, 50,) thirty- 

 two determinations wifere mad© of th© watar soluble acid 

 radicles In the soil under corn. There was a wid'* varia- 

 tion of soil typ«s, studied in various stat«ijs. Th® data 

 is the sum of results for four feet i^nd is accordinsly 

 given in parts per four millions (x>p'/-m) dry soil. The 

 rang* of KO^, PP^ ^ was 3.17 to 334. 3S , 12 r^n below 

 10 pp.y m. . 37^ of the determinations showed lidss than 

 2.5 p. p.m. NO^ par foot. The rang© in HFO^ was 2.44 to 

 39.56 p.p.jfan. 



Thasa show a wida variability for both N0« an4 HPO4. 



