Manures in General 



and Ph. Ac. are not restored to the soil m sufficient 

 quantities. Obviously the fault is that the farmer 

 has not returned to the soil a sufficient proportion of 

 the nutritive value which he has taken from it. 



But if by means of manure he replaces the matter 

 which the crops have taken out in excess will he 

 still have a margin of profit ? Yes. Because the 

 reinforcements of manure represent a great increase 

 of value in the crops, and the nitrogen, Potash and 

 Ph. Ac. as aliments have a much greater value per 

 unit than as manure. It is just as economical an 

 operation as the transformation of foodstuffs into 

 living stock, about which the farmer has no doubt 

 whatever. 



Acids. — Acids are chemical compounds, having 

 the property when brought in contact with bases, 

 and associating with them, of forming salts, at the 

 same time losing their acidity. An acid soil, there- 

 fore, is one in which acid predominates. In other 

 words it is a sour soil. 



Base, or alkali. — Any substance which has the 

 property of neutralising acids by forming a salt. 

 By the addition of a base to an acid the quality of 

 the acid is destroyed. A basic soil or alkaline is 

 therefore a soil in which bases predominate. 



Neutral. — This is the intermediate point between 

 the acid and the basic states, when the action of the 

 acids and the bases counterbalance each other. 



The Functions of Manures. 



In the distribution of roles attributed to these 

 manures, nitrogen forces and makes the grass grow, 

 and also increases the volume of vegetable matter, 



30 



