44 CHEMICAL MANURES. 



my experiments here at Vincennes, having nothing to direct me but 

 theoretic views, which I wished to reduce to facts, I first asked, What 

 will be the duration of a good manuring with chemical fertilizers ? 

 The manure employed was as follows : 



The acre. 



Phosphate of lime 355 Ibs. 



Potash , 118 " 



Lime 266 " 



Sal ammoniac ' 577 " 



which represents 151 pounds of azote the acre. 



The land was given me too late to sow in wheat in autumn ; I 

 sowed it in March. 



The growth was very pretty ; the stalks shot up with so much vigor 

 they fell down, which injured the harvest. However, all things 

 counted, the return showed 44 bushels of grain and 3777 pounds of 

 straw. 



The second year the same accident happened, consequent on a still 

 more luxuriant growth. It not falling until late, the return was more 

 affected ; it descended to 34 bushels of grain and 6168 pounds of 

 straw. 



The third year the grain was sown in autumn instead of March, 

 and things were different. This time the growth was equally splen- 

 did, but the stalks did not fall. So the returns were increased to 67 

 bushels of grain and 6168 pounds of straw. 



Lastly, the fourth year I obtained 34 bushels of grain -and 4000 

 pounds of straw. 



The total of these four harvests is represented by grain, 179 

 bushels ; straw, 20136 pounds giving a mean of grain, 44 bushels ; 

 straw, 5034 pounds. 



What conclusions can we draw from this experience ? Two. The 

 first is, that 151 pounds of azote is too much at one time the acre for 

 wheat, because accidents are then almost inevitable : if it does not 

 fall, it rarely escapes rust ; and if it avoids both, the straw is so fully 

 developed that the return of grain is diminished. I propose to you 

 the following formulae, which at present I consider the best : 



First Year Wheat. 

 Complete fertilizer No. 1, 1066 pounds. 



>~y . , . The acre. 



(Composition : Quantity. Price. 



Phosphate of lime , 355 Ibs. $ 5.40 



Nitrate of potash 177 " 10.47, 



Sulphate of ammonia 222 " 9.50 



Sulphate of lime 311 " .59 



Cost $25.96 



Second Year Wheat. 



Sulphate of ammonia 266 Ibs. $11.40 



Cost >.. $11.40 



