Food for 

 ints 



127~ 



phoric acid, and 8 pounds of potash. The losses by the 

 treatment given manures on the average farm, where at ^^ 

 least some pretense is made to care properly for same, was 

 4 pounds of ammonia, 3 pounds of phosphoric acid, and 

 4 pounds of potash. As compared with pure chemi- 

 cal fertilizers the plant food lost amounted to about 85 

 cents. However, in actual farming it has been long since 

 known that the plant food elements in the form of farm- 

 yard manure are not nearly so valuable as the same elements 

 in the form of pure fertilizer chemicals. We have no 

 absolutely exact way of fixing this difference in figures; but 

 it is very probable that all things considered, plant food in 

 farmyard manures is worth about half as much as the same 

 quantity in the form of the pure farm chemicals. Under 

 these conditions the actual value of the plant food saved 

 by a very carefully carried out system of preserving farm- 

 yard manures would not amount to more than 45 cents 

 per ton, which probably would scarcely pay for the work 

 of saving it. 



The value to the farmer of manures Crop-Producing 

 and fertilizers depends upon the crop p^^^^ qJ Nitrate 

 making power of same; that is, the ^^^p^^^^ ^j^j^ 

 power of the manure or fertilizer to q^j^^j. Ammo- 

 make a greater growth than would have j^j^^^g 

 been the case had no manure or fertilizer 

 been used. Plant food ammonia is a definite substance, but 

 unquestionably it has a greater crop making power in some 

 forms than in others. All the fertilizer ammoniates vary 

 in practical usefulness, ranging from the Nitrated Ammoniate, 

 Nitrate of Soda, which is the form of highest value to 

 the farmer, to the animal form in leather scrap, which is 

 of very little agricultural value. This variation in the crop 

 making values of ditferent forms of ammoniates has been 

 specially studied by the Experiment Station, making use 

 of the plot system. The experiment plots were treated 

 with an abundance of phosphoric acid and potash, and 

 given ammonia at the rate of 60 pounds per acre — 320 

 pounds of Nitrate of Soda. The results averaged for three 

 years (corn, oats, oats) were as follows, comparison made 

 with a plot receiving phosphoric acid and potash, but no 

 Nitrate : 



