CHAPTER VII 

 COMMERCIAL FERTILIZERS 



104. Necessity of commercial fertilizers. It is not 

 uncommon to find market gardens managed successfully 

 without the use of commercial fertilizers. In all such 

 cases stable manures and perhaps night soil are applied 

 in liberal quantities. Although it is possible to make 

 large profits when fertilizing with manures only, it is 

 doubtful whether there are any instances when commer- 

 cial fertilizer in some form could not be used to ad- 

 vantage. Manure is an unbalanced ration ; it is richer 

 in nitrogen than in mineral elements and there is likely 

 to be a surplus and, therefore, a waste of nitrogen when 

 it is applied without corresponding additions of potash 

 and phosphoric acid. 



The most forceful argument for the use of commercial 

 fertilizers is the inadequate supply of animal manures. 

 While hundreds of market gardeners near the cities de- 

 pend mainly upon stable manures, thousands of truckers 

 remote from the great sources of supply must resort to 

 the use of commercial fertilizers in order to secure maxi- 

 mum returns. 



There are other reasons for the use of commercial fer- 

 tilizers. Stable manure must undergo changes before it 

 is accessible to plants, while some of the commercial fer- 

 tilizers are immediately available when incorporated with 

 moist soil, a characteristic which gives chemical ferti- 

 lizers a great advantage over stable manure, for it is pos- 

 sible to mature crops in less time by their use than can 

 be done with manure alone. Rapid growth is of immense 

 importance in commercial vegetable gardening. There- 

 tore, with the aid of commercial fertilizers the gardener 



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