109 



It will be seen that Dyer's solution and Peter's solution resemble each other 

 in a general way in their action on the phosphates ot' the Kentucky soil (rich in 

 phosphates) and on the Turley soil (poor in phosphates^; while on the Campbell 

 land (poor in phosphates), and on the station land (fairly good in phosphates) 

 they differ radically. ^ 



In their action on potash the two solutions differ widely in the case of the 

 Kentucky soils containing too little available potash for corn, while they resemble 

 each other in their action on the other soils, which seem from field tests with corn 

 to contain considerably higher available potash than the Kentucky soils. 



Dyer's solution extracts more phosphoric acid from the Kentucky soil that had 

 received phosphoric acid than from the one receiving none. From the station soil 

 it extracts the highest phosphoric acid from the soil that had received superphos- 

 phate ; but it failed to extract as much phosphoric acid from the soil receiving 

 its phosphoric acid in the form of manure as it extracted from either of the plats 

 that had received no fertilizers. On the average. Dyer's solution extracts no 

 more phosphoric acid from the station soils known to contain a fair supply of 

 available phosphoric acid than from the clay soils known to be very deficient in 

 phosphoric acid. 



Dyer's solution dissolves more potash from the Kentucky soil that had re- 

 ceived potash than from the one not receiving any. 



From the clay soils, which seem from field tests with corn to be somewhat 

 deficient in available potash, it dissolves relatively high amounts of potash. 

 From the station soils it dissolved no more potas-h from the soil that had received 

 full applications of muriate of potash than from the soils that had received no 

 potash. 



Peter's solution would indicate that there was a good supply of available 

 phosphoric acid in the Campbell soil, where it is known to be deficient. It would 

 also indicate that the Turley land was higher in available potash than the station 

 soil, although the field tests indicate to the contrary. 



The acid solutions of Dyer and Peter seem to fail when applied to soils of 

 different types, although their indications are in the right direction when applied 

 to soils of exactly the same type, such as the Kentucky soils. 



The alkaline ammonium oxalate dissolves practically as much potash from 

 the Kentucky soil as from the station soil, although the available potash is much 

 higher in the latter, as shown by field tests. 



