EXPERIMENTAL AGRICULTURE. J21 



The mineral fertilizer alone, prodnced on an average 45 l)nshels 

 of shelled corn per acre, at a cost of about $8.25 per acre for 

 fertilizers. The mineral fertilizers, with the addition of 24 pounds 

 of nitrogen, produced nine bushels more corn, at an additional cost 

 of about G.OO, or at a cost of about GG cents per bushel for the corn, 

 with the cobs and stalks, for the increase above what was produced 

 by the mineral fertilizers alone. Witli the mineral fertilizers and 

 48 pounds of nitrogen, there were produced 10 bushels more corn 

 than with the mineral fertilizers alone, but at an extra cost of about 

 $12.00. The cost of corn per bushel, with cobs and stalks, above 

 what was produced by the mineral fertilizers, in this case amounts 

 to SI. 20. With mineral fertilizers and 72 pounds of nitrogen, there 

 were produced 11^ bushels of corn more than the mineral fertilizers 

 produced, at an increased cost of $18.00, or at a cost of $1.56 

 per bushel for the extra corn produced. The nitrogen application 

 paid for itself in the increased crop only in the case where 24 pounds 

 per acre was used. In the other cases there was a decided loss. 



If we take the mixed minerals with 24 pounds of nitrogen to the 

 acre as a basis from which to reckon the profits or losses of the ex- 

 periment, we see that an application of an extra 24 pounds produced 

 an increase of only one bushel, and that the extra cost was $G.OO ; 

 and that 48 pounds extra increased the crop onlj' two bushels, at an 

 extra cost of $12.00. 



The average of 75 general experiments, gave with mixed minerals 

 alone, 43.4 bushels shelled corn per acre ; mixed minerals with 24 

 pounds nitrogen, 47.8 bushels shelled corn per acre. The increase 

 in crop in these experiments, produced by an application of 24 

 pounds of nitrogen per acre, was only 4.4 bushels, and at a cost of 

 $6.00, or $1.36 per bu.shel for the increase. 



In calculating the cost of the increase in the crop produced by the 

 nitrogen application, I have taken 25 cents per pound as tUe value 

 of tlie nitrogen, which is about its average cost in nitrates and am- 

 monia salts. 



It may be worth while to give these results a little more in detail, 

 in order to show that they are really quite as important as I have 

 made them appear. I therefore copy two more tables from the same 

 report. 



