FLORIDA STATE HORTICULTURAL SOCIETY. 
99 
nesiuiiT. When these bases are dissolved 
by the soil waters, or when they are added 
in alkaline compounds, they immediately 
combine with these neutral constituents— 
silicates and non-acid organic compounds 
—and thus the soil is prevented from be¬ 
coming alkaline until the above mentioned 
affinity is satisfied. This condition, while 
harmful to sensitive plants, is probably not 
so harmful as the presence of free acids 
or acid salts. Further than this, there 
is good evidence going tO' show that the 
reaction which takes place between cer¬ 
tain of these soil constituents and added 
chlorides and sulphates, produces positive¬ 
ly acid salts. There can be but little doubt 
that it is due, partly at least, to the acidity 
thus produced, that the injury arising 
from the use of chlorides and the sulphate 
of ammonia on neutral or acid soils is to 
be ascribed. It was found in experiments 
at the Rhode Island Experiment Station 
with different forms of nitrogen on acid 
soils, that sulphate of ammonia was pos¬ 
itively poisonous to plants when it was 
not used in connection with lime. When 
the acidity of the soil was corrected by ap¬ 
plications of air-slaked lime, the sulphate 
of ammonia was beneficial. This benefi¬ 
cial effect is attributed to the fact that the 
lime restored the alkaline condition of 
the soil necessary to the transformation 
(by nitrification) of the sulphate of am¬ 
monia into nitrates, sO' necessary to most 
crops. I would not therefore, recom¬ 
mend a reduction in the amount of fertil¬ 
izers to be used, but would remedy the 
evil by a liberal application of lime once 
in two or three years, or oftener if found 
necessary. 
The causes above mentioned are gen¬ 
eral ; there may also be local causes which 
are responsible for this acid tendency. In 
some parts of the State sulphur water (wa¬ 
ter containing hydrogen sulphide, H2 S) 
is used for irrigating purposes. Now 
when hydrogen sulphide gas comes in con¬ 
tact with air, the hydrogen unites with 
oxygen to form water; but it is also^ true 
that some of the sulphur may be oxidized 
to sulphuric acid, and where this system of 
irrigation is carried on for years at a time, 
keeping the ground wet during a good 
part of the year, the aiccumulations of sul¬ 
phuric acid and sulphates may reach con¬ 
siderable proportions. Under such con¬ 
ditions injury to crops may eventually be 
expected, unless lime is used in liberal 
quantities. A statement made to me re¬ 
cently by a celery grower of Sanford 
would seems to bear out this theory. He 
said that a few years ago only a few 
barrels of lime were used in Sanford, but 
that now the market could scarcely supply 
enough. No dou 1 )t this increased de¬ 
mand is partly due to the increased aicre- 
age, but it is no doubt also' due in part, 
to the fact that the growers are learning 
that without it they cannot get good re¬ 
sults. This same grower said that he 
used about a ton to the acre. Notwith¬ 
standing this fact, a test of several soils 
at this point, his among others, showed an 
acid reaction. Examples of the oxidation 
of sulphides, with the formation of sul¬ 
phuric acid, are to be found in the vicinity 
of coal mines. Whole tracts of land have 
become priactically sterile from having 
been saturated with water containing free 
acid and ferrous sulphate formed by the 
oxidation of iron pyrites. 
WILL THE CONDITION OF FLORIDA SOILS 
BE IMPROVED BY THE USE OF LIME.^ 
On this point also there has been no 
systematic investigation, but if the sandy, 
sour soils of Rhode Island and Massachu¬ 
setts, of France, England, and Germany, 
