MANURES. 



13 



plant food are made available. The same may be said of 

 unleached ashes, though it contains much more valuable fertil- 

 izing material than lime. Common salt also acts to some 

 extent indirectly as a fertilizer, while it is of very little value 

 as a plant food. 



COMPOSITION OF VEGETABLES, MANURES AND FERTILIZERS. 



In the following tables is shown the amount of fertiliz- 

 ing elements required by vegetables and the amount of these 

 materials which is contained in the various farm manures 

 and commercial fertilizers. These figures are from eastern 

 United States and European sources. The climatic con- 

 ditions in these places are quite different from those in many 

 sections of the western states where the actual amount of ash 

 ingredients in plants, especially in dry years, may greatly ex- 

 ceed the amounts here given. The relation of these tables to 

 one another is worthy of special study, since they show what 

 the plants need and what fertilizing materials supply. 



