MANURES 49 



Potatoes and beetroots thrive extremely well when 

 treated with it. 



Liquid Excreta are extremely rich in nitrogenous 

 matter and, therefore, are of much value if applied 

 sparingly and well diluted. They are best after storing 

 three weeks at the very least, six weeks for preference 

 especially when a small quantity of sulphuric acid is 

 added to fix the ammonia. Growing crops of the 

 brassica family thrive well when fed with this form of 

 manure. 



Bones contain an extremely high percentage of phos- 

 phates and are, in consequence, a most useful food for 

 plants. In the uncrushed state, however, they take 

 many years before being assimilated, a drawback which 

 does not apply to bone flour. The steamed varieties of 

 the flour have been deprived of the fatty substances and 

 are far more attractive in consequence. Dissolved bones 

 are supplied in a commercial form. This manure con- 

 tains a slightly lower percentage of phosphates than the 

 steamed bone flour ; it is also of an acid nature, and, 

 therefore, must not be used on land lacking lime. 



Basic Slag is a phosphatic manure derived from 

 transforming pig iron into steel. Its influence on soils 

 is somewhat erratic, but we may safely say that on most 

 lowlands it is highly useful though of little value on dry 

 uplands. As a dressing where club root disease is feared 

 it is most beneficial, but must be withheld from land 

 treated with sulphate of ammonia. 



Superphosphate was a cheap and extremely valuable 

 phosphatic, quick acting manure which formed an 

 autumn or spring dressing. Since the War it has been 

 somewhat difficult to obtain. 



