192 Agricultural Chemistry. 



assimilation of food. These crops feed heavily upon lime, potash 

 and phosphoric acid. This fact is to be attributed largely to 

 their extensive root systems, drawing from a wide range of soil 

 for a large production of dry matter. As a consequence, these 

 crops are especially benefited by the inorganic constituents of 

 manures. 



The reappearance of clover in limed meadows is a commonly 

 observed indication of the value of this fertilizer. Wood ashes 

 benefit these crops chiefly by reason of their content of lime and 

 potash. The following fertilizer ration per acre has been re- 

 commended for clover and alfalfa: 40 pounds of nitrate of soda 

 or 1 ton of farm manure ; 500 pounds of bone meal ; 150 pounds 

 of muriate or sulphate of potash, or 1500 pounds of wood ashes; 

 1 to 3 tons of ground lime-stone, as required. 



Ensilage is properly a hay crop. It is principally prepared 

 from corn, although sorghum, millet, clover, cow peas and other 

 succulent crops have been so treated. The production of good 

 silage depends upon careful exclusion of the air. Under this 

 condition the -mass undergoes changes involving the consumption 

 of oxygen and production of compounds not previously existing 

 in the fresh material. The temperature of the mass rises and 

 reaches its maximum in two or three days. These changes were once 

 thought to be due chiefly to organisms producing alcohol, lactic 

 and acetic acids, and other products of fermentation. Babcock and 

 Russell, as a result of their studies on silage, have concluded that 

 bacteria are not the essential cause of the changes within the silo, 

 but are probably deleterious and exert their influence only in the 

 production of objectionable putrefactive changes. These in- 

 vestigators further conclude that the changes in the silo are 

 chiefly due to the respiration of living plant cells. This process 

 either may involve the oxygen confined in the air spaces of the 

 ensiled material, in which case it is known as "direct respira- 

 tion," or it may utilize only the oxygen of compounds in the 

 plant tissue, this process being known as " intra-molecular respir- 

 ation." Both forms of activity cease with the death of the plant 



