FLORIDA STATE HORTICULTURAL SOCIETY. 
69 
average of a number of analyses, 15 
pounds actual phosphoric acid, 25 pounds 
nitrogen and 79 pounds of actual potash, 
or a total of 119 pounds of actual plant 
food. 
This does not take into account that 
which is removed with slips and suckers, 
which unfortunately has not yet been de¬ 
termined, but allowing that these would 
remove as much as the fruit, which is, 
I believe, an exceedingly liberal allow¬ 
ance, there would be removed from the 
acre a total of 238 pounds of plant food 
against 712 1-2 applied, a loss somewhere 
amounting to 474 1-2 pounds—66.6 per 
cent. 
To take a more familiar instance, the 
grower who puts on 3000 pounds per acre 
of a fertilizer which would analyze 4 p>er 
cent, available phosphoric acid, 5 per cent, 
ammonia, and 7 1-2 per cent, potash, ap¬ 
plies 120 pounds actual phosphoric acid, 
123 pounds nitrogen and 225 pounds ac¬ 
tual potash, or a total of 468 pounds of 
actual plant food, and if he gathers 350 
crates of pineapples per acre, which would 
be a good average yield, he removes from 
his soil 10.36 pounds actual phosphoric 
acid, 17.32 pounds nitrogen, and 55.26 
ix>unds actual potash or a total of about 
83 pounds of plant food from the acre. 
If here, as before, we allow that slips 
and suckers taken off, remove an amount 
equal to the fruit, the total amount re¬ 
moved in this case would be 166 pounds 
against 486 applied, a loss somewhere of 
302 pounds—64.5 per cent. But this pro¬ 
bably does not represent the entire loss, 
for in many instances there is added, over 
and above what has been counted, some 
phosphoric acid which is not reckoned as 
available, but which, nevertheless, does 
Income slowly available, and undoubted- 
1v some of this would be lost. 
WHERE THE BALANCE GOES. 
Now what becomes of this lost plant 
f(X>d? If it remained in the soil within 
reach of the plant, the soil would increase 
in fertility more rapidly than it does. We 
are driven to the conclusion that the 
greater part of it is carried down by the 
rains and is finally lost in the water table 
below. Perhaps a small amount of the 
nitrogen escapes into the air. 
A LABORATORY DEMONSTRATION. 
In an effort to explain this unprecedent¬ 
ed loss, for certainly in no other field 
crop is the percentage of loss so great, 
I have recently conducted some experi¬ 
ments to show the rate at which water 
percolates through different typ^s of soils, 
and the consequent loss of plant food. 
And while it is true that the conditions 
in the laboratory were not the conditions 
that exist in the field, still the results are 
relative, and serve in a way, to illustrate 
what takes place in the soil. 
Four glass tubes of equal size were 
taken and one end closed with perforated 
disc and filter paper, thus retaining the 
soil but allowing a solution to pass 
through. Into each was placed air dried 
soil as follows: No. i, 150 grams (be¬ 
tween five and six ounces) of South Car¬ 
olina clay soil; No. 2, 150 grams Colum¬ 
bia Co. virgin soil; No. 3, 150 grams of 
typical pineapple soil, and No. 4, 150 
grams of muck soil. Into each was pour¬ 
ed TOO cubic centimeters (a little less 
than a gill) of water containing one 
gram of sulphate of ammonia, and the 
following observations made: 
i ) Time required for the solution to 
begin dropping through. 
(2) Time of completion. 
