SECTION XIX. SUITING THE FERTILIZERS 

 TO THE SOIL 



THE amount of fertilizer per acre varies with the land 

 and with the crop. Vegetables and cotton generally pay 

 better for large amounts of fertilizer than does corn. For 

 cotton, many farmers use only 200 pounds per acre. Good 

 farmers often use 400 to 600 pounds. Growers of vege- 

 tables increase this to as much as one half or one ton 

 of commercial fertilizer per acre. As labor and land 

 become scarcer or higher it pays to increase the amount 

 of fertilizer. Some land may be too poor for very 

 large amounts of fertilizer to be very profitable. This is 

 because a poor soil may be so shallow or so deficient 

 in vegetable matter that in dry weather it can hold just 

 enough water to make good use of only 300 pounds of 

 fertilizer per acre. When this same soil is made deeper 

 and supplied with vegetable matter, it may hold enough 

 moisture to use profitably double this amount. 



Experienced farmers often apply more phosphate than 

 the crop will remove from the land because the clay or 

 iron in the soil changes some of it into a form that plants 

 cannot use. This cannot be prevented and fortunately 

 phosphate is not very expensive. Nitrogen, however, is 

 about three times as expensive as phosphoric acid, hence 



108 



