24 

 EYE. 



Thirty bushels estimated product of an acreof 50 Ibs. to 

 the bushel = 1,500 Ibs.; the same weight as 25 bushels of wheat. 

 This crop requires at least 3,000 Ibs. of straw. The grain and 

 straw contain : 



Grain. Straw. Total. 



Ammonia 34.05 Ibs. 8.70 Ibs. 42.75 Ibs. 



Phosphoric Acid 13.65 " 8.10 " 21.75 " 



Sulphuric Acid. 7.50 " 3.00 " 10.50 " 



Lime 1.05 12.30 13.35 



Magnesia 2.25 " 4.50 " 6.75 u 



Potash " 8.55 " 24.00 " 32.55 " 



Silica 7.80 " 90.00 " 97.80 " 



By comparing the above table with the one giving the com- 

 position of wheat, the reader can understand why larger con- 

 tinuous crops of rye than of wheat can be raised from the same 

 soil ; because rye does not require so much of those elements 

 which are first exhausted in soils as wheat does. In like man- 

 ner, by studying the composition of different crops, and noting 

 the amounts of the different elements required to produce them, 

 we can understand why farmers should have a dollar for a 

 bushel of wheat, when corn is selling at fifty cents, and rye at 

 seventy-five, Such an examination shows that the quantity, 

 and consequently the price of any crop, are naturally regulated 

 by the amount of certain valuable substances required for its 

 production. 



OATS. 



Fifty bushels of oats the estimated product of an acre 

 of 33 Ibs. to the bushel=l,650 Ibs. This amount of grain re- 

 quires about 2,000 Ibs. of straw. The grain and straw contain : 



Grain. Straw. Total. 



Ammonia 37.45 Ibs. 7.80 Ibs. 45.25 Ibs. 



Phosphoric Acid 10.39 " 4.00 " 14.59 " 



Sulphuric Acid 6.62 " 3.20 " 9.82 " 



Lime 1.81 " 7.40 " 9.21 " 



Magnesia 3.47 " 3.80 " 7.27 " 



Potash 7.59 " 6.00 " 13.59 " 



Silica ; 2.14 45.40 " 47.54 " 



The reader will note the large amount of ammonia required 

 by this crop. This accounts for the nutritive properties of the 

 grain and straw. The amount of phosphoric acid and potash is 

 small compared with that of other cereals. 



