AFTER CARE — FERTILIZERS 39 



plant food required are made up by minerals, 

 such as nitrate of soda, acid phosphate and 

 muriate of potash. 



The statement is often made that well- 

 rotted manure, thoroughly worked into the 

 soil, is the best fertilizer. This is quite true 

 in the majority of cases, especially where an 

 abundance of the material is used. 



Why is this so.^ 



I. Manure contains a large amount of 

 vegetable material, sometimes called humus, 

 which improves the physical conditions of 

 the soil by: 



(a) By making a clay soil less compact, 

 resulting in a more open and porous soil. 



{b)By making a sandy soil less leachy and 

 porous. 



(c) By making both these soils retain 

 more water, thereby somewhat preventing 

 drought. 



(d) By permitting ease of root growth. 



(e) By giving the roots greater feeding 

 surface. 



(/") By increasing the activities of the soil, 

 thereby increasing the available plant food, 

 etc. 



Oftentimes, from lack of humus, low 



