Humus-forming materials are, therefore, necessary 

 to successful and practical farming. The best results 

 from inorganic fertilizers, such as rock and acid 

 phosphates, Thomas slag and sulphate of potash, 

 are obtained when they are used with manure, or 

 blood, or blood and bone, or a green cover crop 

 turned under. 



CULTIVATION AND FERTILIZERS. 



Cultivation increases the availability of fertilizers 

 by aiding nitrification and by saving soil moisture. 

 All organic forms must first decay and then be turned 

 into nitrates (nitrification), and other salts before 

 water can carrv- their elements to the roots of plants. 



The decomposed matter (humus) is attacked by 

 nitrifying bacteria and these require oxygen for their 

 work. Cultivation increases this supply of oxygen 

 so that nitrification proceeds faster, and better 

 growth results. The more frequent and deep the 

 cultivation, the better the nitrifying bacteria can 

 work. The size of fruit may be increased in this way, 

 or a short season made equal to a long one. 



This principle of aiding nitrification applies to all 

 forms of animal and vegetable fertilizers such as yard 

 manure, blood, raw bone, guano, tankage, and peas 

 or clover, planted for their fertilizing value when 

 ploughed under. 



Frequent, deep cultivation increases the supply 

 44 



