THE FLOWER GARDEN 311 



is by stirring the soil so that the air makes it 

 possible for the root hairs to secure the elements. 

 Another is by supplying sufficient air and 

 moisture so that the elements in the soil will be 

 dissolved. And the third is by applying fertil- 

 izers, which supply the plant foods needed, in an 

 available form. 



It does not always follow that when the jneld 

 of a certain piece of land is small, that land 

 needs fertilizers. It is very often the case that 

 the poor yield is due to poor seed or shallow 

 culture, or other cause. If great care is taken 

 in selecting seed from the highest yielding 

 fields year after year, one will then know that 

 when the small yield comes it is due to some- 

 thing else. 



Expensive fertilizers are sometimes added 

 when a thorough stirring of the soil, drainage, or 

 irrigation would accomplish the same result. 



Soil that is producing fruit crops needs less 

 fertilizing than that producing grain crops. The 

 fruits contain such a large percentage of water 

 that the essential elements of fertility are ex- 

 hausted from the soil very slowly. 



On the other hand, grain contains a large per- 

 centage of the essential elements of soil fertility 

 and it is necessary to add fertilizers to grain 

 fields much more often than to orchards. 



