agricultural experiment stations
upon the effect of "apple stock," that is, young trees raised for
nursery purposes, on the soil, showed that in eleven tons of such stock
the following quantities of ingredients were removed from the soil:

Silica 50.6 lbs.
Phosphoric acid 21.4 "
Sulphuric acid 14.3 "
Chlorine 1.3 "
Carbonic-acid gas 94.9 "
Iron oxide 6.1 "
Lime 138.6 lbs.
Magnesia 23.7 "
Soda 21.3 "
Potash 27.1 "
-----------
Total 399.3 lbs.

This is no inconsiderable quantity of material to be removed by a single
crop.

Professor Goessmann, in discussing the ash of fruits, gives the
following analysis of the ash of the Baldwin apple; this would represent
the mineral matter taken from the soil by the fruit: Potash, 63.54 per
cent.; soda, 1.71; lime, 7.28; magnesia, 5.52, and phosphoric acid,
20.87. Comparing this with the ash of other fruits, it is seen that the
amount of potash required is larger than in the case of other fruits
except plums and peaches, and the amount of phosphoric acid is high, but
not as high as in the case of some berries. The application is obvious;
in order to successfully raise apples there must be an abundance of
potash and of phosphoric acid in the soil, and these ingredients must be
in an available form.

If we compare the apple and the pear by an analysis for fertilizing
constituents, or such constituents as are usually introduced into
deficient soil by means of fertilizers, we have the following table:
1000 parts of the fruit contain, in the case of each,

H2O N Ash K2O Na2O CaO MgO P2O5 SO3 SiO2
Apple 831 0.6 2.2 0.8 0.6 0.1 0.2 0.3 0.1 0.1
Pear 831 0.6 3.3 1.8 0.3 0.3 0.2 0.5 0.2 0.1

When we study the composition of the apple, to determine the "proximate
principles," as they are called, it is noticed that we have the
constituents mentioned in the discussion of the elements contained in
the fruit combined to form various substances; thus:

Apples. Pears. Cherries. Peaches.
Water 82.04 83.95 75.73 84.99
Sugar 6.83 7.00 13.11 1.58
Free acid .85 .07 .35 .61
Albuminous substances .45