FLORIDA ;STATE HORTICULTURAL SOCIETY. 
in 
gressed farther, at the same time I am 
free to make the assertion that in the 
making of a grove natural phosphates 
(that is, finely-ground untreated rock) 
may, to a large extent, replace the acid- 
treated rock or acid phosphate. A ton 
per acre of this finely ground rock should 
be applied at the time of setting out the 
trees, and an additional ton at intervals 
of two to three years. If the soil is kept 
well cultivated and is supplied with an 
abundance of humus, and receives an oc¬ 
casional treatment of lime or ground lime¬ 
stone, no orange tree in such a grove will 
suffer for the want of phosphoric acid. 
This method would materially reduce the 
cost of fertilizing, because the materials 
would be cheaper and the expense of 
handling less. These statements are made 
with reference to the orange, but will, I 
believe, apply equally to the pineapple. 
They are not intended to apply to vege¬ 
table and other quick-growing crops ; 
though I am confident that the raw rock 
may, with profit, be used much more 
widely than it is at the present time. 
Reference should be made to the fig¬ 
ures for Tank 4, since the results for this 
tank are higher than for the others. I11 
explanation of this it may be stated that 
in taking out the soil for this tank, char¬ 
coal and bits of burnt sticks were found 
in the first foot or two, showing that at 
this point a stump or pile of logs had 
been burnt when the land was cleared 
a few months before. The presence 
of ashes made the conditions for nitrifica¬ 
tion more favorable, with the result that 
more of the nitrogen of the organic mat¬ 
ter was converted into nitrates than in the 
other tanks, and the nitrates thus formed 
appear in the drainage water. The pres¬ 
ence of ashes would also explain the high 
phosphoric acid, potash, lime, and mag¬ 
nesia in this tank. This affords an ex¬ 
cellent illustration of how alkaline mate¬ 
rials applied to our acid soils promote 
nitrification, and is perhaps a hint to us 
to apply them at some other time than at 
the beginning of the rainy season, unless 
there is a vigorous crop on the land to 
take up the nitrates that are formed. 
The question will naturally be asked r 
“Would not some of this soluble matter 
be again brought within reach of the 
plants by capillary action, under nor¬ 
mal field conditions?” At times when 
rains are not heavy, no doubt some of the 
fertilizing constituents would thus be 
brought within reach of the plant. In 
times of heavy and long-continued rains, 
and especially during the rainy season, 
when it is raining almost every day and 
water is constantly running out of the 
soil into small streams, ponds, lakes and 
rivers, we necessarily lose all that material 
which is dissolved in the water that runs 
off. It is a part of our research to learn 
under what system of fertilizing we can 
get good results, and at the same time 
have a minimum of loss in the drainage 
waters. 
The work is only begun, but it bids fair 
to give us some really valuable results. It 
will take several years of careful and 
painstaking work to secure the knowledge 
that we need. As funds are available, 
other units or batteries of tanks will be 
installed to enable us to take up other 
phases of the fertilizer problem. 
Credit is here given to Assistant Chem¬ 
ist Mr. S. E. Collison, for a large share 
of the analytical work involved. 
