TOBACCO CULTURE. 33 



quirements. He found the average Florida tobacco plant 

 to contain: 



Phosphoric Acid Nitrogen Potash 



0.99 per cent. 2.58 per cent. 4.34 per cent. 



This indicates that the crop requires its plant food in 

 the proportion of 260 pounds of nitrogen, and 440 pounds of 

 potash for every 100 pounds of phosphoric acid actually 

 taken up by the plant. As phosphoric acid is apt to change 

 into insoluble forms in the soil, allowance must be made for 

 such losses in making up special fertilizers. Again, many 

 soils accumulate supplies of nitrogen through the growth of 

 legumes in rotation, and a too free supply of nitrogen in the 

 fertilizer may prove very undesirable by inducing a too 

 rank growth of leaf. For these reasons, many experienced 

 tobacco growers use a higher proportion of phosphoric acid, 

 and a lower proportion of nitrogen than the chemical com- 

 position of the crop would seem to require. 



Prof Stockbridge's recommendation for fertilizer appli- 

 cation is based on these condiiions, and his formula supplies 

 the necessary plant foods, (as shown by the analyses) which 

 will be removed from an acre of land by a fair crop of 

 tobacco. 



Dr. Jenkins, of Connecticut, as the result of his analy- 

 ses, estimates the quantities of the three essentials removed 

 from the soil by an average Connecticut crop per acre as 

 follows; Phosphoric Acid, i<> Ibs.. Nitrogen, 100. Ibs., and 

 Potash 150 Ibs. 



