FLORIDA STATE HORTICULTURAL SOCIETY. 
123 
on very acid soils and lime is not a cure 
for blight. An acid soil is not very de¬ 
trimental to Irish potatoes, and stable 
manure or lime favors scab, of Irish po¬ 
tatoes in Florida grown successive 
winters seems to> fall off even with inter¬ 
mediate summer crops. 
There are a great many questions in 
plant nutrition that ought to be settled 
and as to which we can only conjecture. 
Rev. Lyman Phelps discovered that 
an excess application of sulphate of am¬ 
monia in summer or a spray of bi-sul- 
phate of soda prematurely sweetened or¬ 
anges. Winogradsky of Zurich, the dis¬ 
coverer of nitrifying bacteria, found that 
liquid grown plants would healthfully 
assimilate considerable sulphate of am¬ 
monia. The ammonia of sulphate of am¬ 
monia takes the place of an alkaline sait 
like lime or potash combining with the 
sulphuric acid. 
What becomes of the sulphur? When 
sulphate of ammonia solution is ab¬ 
sorbed by orange trees? Small percent¬ 
ages of sulphur are found in the nitro¬ 
genous protoplasm of the sap of the 
plants. 
Reasoning from analogy, is it not pro¬ 
bable enough sulphuric is freed to have 
a similar effect in sweetening oranges to 
sulphuric acid in the manufacture of glu¬ 
cose or grape sugar from starch? 
There must be considerable sulphuric 
acid excreted by the roots. Is a small 
yearly application of lime to orange trees 
indicated to neutralize the unstable sul¬ 
phur acid compounds if they exist? 
I found premature sweetening of or¬ 
anges with sulphate of ammonia depress¬ 
ing to the trees. 
Nitrate of Soda.—In an Irish potato 
fertilizer experiment years ago on the plot 
using nitrate of soda alone, 4 the foliage 
had a sickly, gray color and the tubers 
a soapy taste. A recent German experi¬ 
ment shows that grains and grass largely 
absorb the soda of nitrate of soda, but 
Irish potatoes, beets, etc., excrete it from 
the roots, leaving soda in the soil. 
Organic Nitrogen.—The albumens of 
organic nitrogen compounds in decay split 
up into poisons similar in chemical com¬ 
position to strychnine and morphine and 
decompose still further to ammonia. The 
soil must not be too acid and nitrifying 
bacteria must be present under favorable 
conditions of tillage, moisture and alka¬ 
line bases to secure nitrification. Who 
has not had plant roots burned by organic 
ammonia ? 
Die-back and foot-rot of the orange 
tree are often traced to the use of or¬ 
ganic nitrogen and there is no doubt in 
my mind that the trees absorb so much 
of these decomposition poisons that the 
sap is wholly or partially paralyzed, the 
sugar, starch and wood forming func¬ 
tions deranged and similar symptoms ex¬ 
hibited to animal blood poisoning. 
Phosphoric Acid.—Experiments have 
shown that a small percentage of the 
phosphoric acid needed by plants can be 
absorbed in its water soluble state. A. 
full ration of soluble phosphoric acid in 
pineapple culture on the East Coast 
spruce pine ridges is corrosive and 
poisonous. There is little lime or humus 
in these soils to revert or hold the acid 
for root acid action. On the other hand, 
I consider the partial sterility of bog ore 
iron hard pan soils due next after their 
acidity to the immediate iron basis re¬ 
version of the soluble phosphoric acid of 
fertilizers, so that quick-growing plants 
cannot get phosphoric acid fast enough 
to harden and perfect their growth. 
Potash.—Potash, besides forming a 
