60 



PRACTICE 26. (Con't.) 



Weight of crucible plus Mg 2 P 2 7 



Weight of crucible 



Weight of Mg 2 P 2 O 7 



Weight of Mg 



Percent Mg 



Average 



PERCENTAGE COMPOSITION OF SOIL. 



Air-dry Basis. Dry Basis. 



Nitrogen 



Phosphorus 



Potassium 



Calcium 



Magnesium 



Iron 



Aluminum 



Sodium 



Insoluble Matter 



Undetermined "> 

 C,H,O, etc. j 



Are carbonates present in the soil? 



If the soil is acid, what percent of calcium carbonate is required to cor- 

 rect the acidity ? 



Suggest a practical method of treatment, of unlimited application, by 

 which the productive capacity of this soil could be profitably increased and 

 permanently maintained. 



