146 



PRACTICAL FARM CHEMISTRY. 



number of pounds of the principal plant foods re- 

 moved in a full crop. 



Full Crop per Acre. 



Apples, 15 tons 



Pears, 10 tons 



Plums, 2 tons 



Grapes, 4 tons 



Berries, 1^ tons 



Sugar Beets, 20 tons 



Carrots, 20 tons 



Mangolds. 20 tons . . 

 Turnips, 20 tons . . . 

 Onions 



Phosph. 

 Acid, Lbs. 



3 

 10 



2 

 12 



2i 

 12 

 24 

 18 

 25 



In all this we have not yet taken any account of the 

 plant foods that have gone into the foliage and the 

 wood of the trees and bushes. Here again potash is 

 just the substance needed in considerable quantity. 

 The leaves dropping in autumn may remain on the 

 ground under the trees and bushes, and thus return 

 their constituents to the soil, or they may be blown 

 away by the autumn gales into fence corners, road 

 sides and ditches, and thus be lost to the soil. The 

 prunings also may be burned up in the orchard or 

 fruit patch giving their mineral constituents back to 

 the soil, or they may be carted off and burned in 

 some back field, where the ashes will do no good to 

 the orchard. Usually there is from these sources 

 at least some loss, chiefly in potash, that together 

 with what the fruit crop has taken off, will have to 

 be made good again by applications of manure. 



The table here given may not be more than ap- 

 proximately correct, yet it shows that in fruit crops 

 we remove from the soil an amount of potash, ten, 

 fifteen, and often more times as large as that of 

 phosphoric acid. Many farmers imagine that or- 



