CHAPTER IX 



FERTILIZERS FOR PEACH ORCHARDS 



The peach needs every kind of plant-food that other 

 plants and all plants need. The proportion of the different 

 food elements and the actual amounts required by different 

 plants vary somewhat, but perhaps not as greatly as is 

 commonly supposed. But even a determination of the 

 amounts of plant-food, both actual and relative, taken up 

 by a tree does not serve to direct the practical, wise, and 

 economical use of commercial fertilizers. 



All plants in their growth require at least ten food ele- 

 ments. These are : carbon, hydrogen, oxygen, nitrogen, 

 potassium, phosphorus, sulfur, calcium, magnesium, and 

 iron. Three other elements, sodium, chlorin, and silica, may 

 be used by plants. The first three named make up 90 to 

 98 per cent of green plants. Nitrogen comprises .2 to 1.5 

 per cent. All the others, totaling from 1 to 8 per cent of the 

 plant's substance, are termed the ash constituents, since 

 they remain in the ashes when the plant is burned. 



Carbon, hydrogen, and oxygen are gases which plants 

 obtain from the air and from water in unrestricted quanti- 

 ties. Nitrogen is also a gas and comprises about three- 

 fourths of the air, but plants as a rule cannot take it in this 

 form direct from the air. It must be combined in the soil 

 with other substances, preferably in a form termed a "ni- 

 trate," or as ammonia. It is taken up in these forms from 



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