68 CHEMICAL MANURES. 



Second Year Wheat. 



The acre. 

 Quantity. Price. 



Sulphate of ammonia 266 Ibs. $11.40 



Third Year Wheat. 

 Complete fertilizer No. 1, 1066 Ibs. 

 Composition : 



Acid phosphate of lime 355 Ibs. $5.40 



Nitrate of potash 177 " 10.47 



Sulphate of ammonia 222 " 9.50 



Sulphate of lime + 311 " .64 



Cost $26.01 



Fourth Year Wheat. 



Sulphate of ammonia 266 Ibs. $11.40 



Total expense $65.82 



That is to say : 



Azote, 241 Ibs., equivalent in harvest to 482 Ibs. 



Phosphoric acid 106 " 



Potash 165 " 



Lime 256 " 



By means of these quantities, renewed every four years, we may 

 easily obtain four harvests of from 44 to 50 bushels, and 4444 Ibs. of 

 straw the acre. Now, if we draw a balance between what the fer- 

 tilizers furnished the earth and what these four harvests took from it, 

 we will find an excess in favor of the soil : 



Fertilizer. Harvest. Loss to soil. Gain to soil. 



Azote, 241 Ibs., equivalent to 482 Ibs. 241 ... 241 



Phosphoric acid 106 " 87 ... 19 



Potash 165 " 99 ... 66 



Lime 256 " 42 ... 214 



You will see, gentlemen, the balance is closed by a general excess 

 in favor of the fertilizers. In the face of these numbers we may 

 with certainty conclude that we have nothing to fear in the future 

 from the use of these chemical fertilizers. 



My experiments in burnt sand confirmed by the culture of the 

 field at Vincennes which have continued now more than eight years, 

 seem to me to put this conclusion beyond all contest. In the preced- 

 ing examples I have intentionally admitted that the whole of the 

 harvest, straw and grain was lost to the domain. I have besides 

 admitted that the land w r as cultivated by the hand of man. By this 

 double supposition the demonstration is carried to the extreme. It 

 is true that this situation is to be regretted ; it is found in France 

 among the small farmers, who are almost entirely without manure, 

 and who, by the extent of the interests they represent, very painfully 

 affect the public fortunes. 



I now take up an alternate culture of colza and wheat, and I still 

 suppose the straw and grain are sold. The fertilizer comprehends 

 four years. 



