23 

 WHEAT. 



Twenty-five bushels of wheat, at 60 Ibs. to the bushel, the 

 product of an acre, weighs 1,500 pounds ; the straw of this 

 grain will weigh 3,000 Ibs. The wheat and straw removes 

 from each acre of land the following weights of the elements : 



Grain. Straw. Total. 



Ammonia 41.71 Ibs. 10.18 Ibs. 51.89 lbs 



Phosphoric Acid 15,00 " 11.10 " 26.10 " 



Sulphuric Acid 1.08 " 5.10 6.90 " 



Lime 1.35 " 12.00 " 13.35 " 



Magnesia 4.65 " 5.10 " 9.75 " 



Potash 12.00 " 2370 " 35.70 " 



Silica 1.05 " 143.10 144.15 



The table shows also the relative amounts of the different 

 elements required to raise wheat. 



INDIAN COKN. 



Fifty bushels of corn the estimated crop of an acre of 58 Ibs. 

 to the bushel = 2,900 Ibs. This weight of corn will require 

 3,000 Ibs. of stalk and cob (when dry), and will contain: 



Grain. Stalk and Cob. Total. 



Ammonia 34.22 Ibs. 6.06 Ibs. 40.22 Ibs. 



Phosphoric Acid 25.81 " 13.50 " 39.31 " 



Sulphuric Acid 2.90 " 8.40 " 11.30 " 



Lime , 87 " 17.70 " 18.57 " 



Magnesia 7.83 " 9.30 " 17.13 u 



Potash 15.08 " 59.70 " 74.78 " 



Silica 2.32 " 81.60 " 83.92 " 



The reader will notice that Indian corn requires much more 

 phosphoric acid and potash than wheat, while the amount of 

 ammonia is only a little more than half as much ; consequently, 

 its nutritive properties as food are in about the same propor- 

 tion; that is, in proportion to the ammonia. Corn stalks con- 

 tain a large amount of potash and silica, and, when properly 



repared as manures, will furnish these elements for other crops. 



"rom the comparatively small amount of ammonia required by 

 the corn crop, it can be raised at less cost to the soil than wheat, 

 because ammonia is one of the most costly of the organic 

 elements. 



