30 FERTILIZERS 



47. Probable order of availability. Phosphates : 



Double super phosphate ) if watered 

 Acidulated phosphates ) at once 

 Phosphorus from tankage, high in nitrogen. 



" " guanos (as in tankage.) 



Thomas slag 

 Steamed bone meal 

 Raw 



4-8. Probable order of availability. Potassium, 

 (potash) substances : 



( Sulphate 

 All commercial forms 1 Muriate 



( Kainit 

 Wood ashes 



Silicates (natural soil forms) 



49. The amount of potash and phosphoric acid 

 carried by drainage and "run off" waters of good, 

 bad and indifferent soils, bear directly on this ques- 

 tion of availability. 



Table : "Matters dissolved by water from 100,- 

 000 parts of various soils." (From Johnson's 'How 

 Crops Feed.') 



The matters least soluble are those found in the 

 ash of plants. Where organic and volatile matter 

 is carried in more appreciable amounts there is 



