FLORIDA .STATE HORTICULTURAL SOCIETY. 
105 
dant supply of humus, even where irri¬ 
gation is practiced. For thereby the loss 
by leaching will be greatly reduced. 
3. Acid Soils .—Again fertilizers may 
be limited in their efficiency by an acid 
condition of the soil. Organic matter de¬ 
caying in the soil results in the formation 
of acids which will accumulate if the soil 
is not naturally well supplied with car¬ 
bonate of lime. These acids are harm¬ 
ful to nitrifying and other friendly bac¬ 
teria, and also to some plant roots. How¬ 
ever, the great need for humus in the soil 
requires us to have the decaying organic 
matter and with it the resulting acids, but 
these acids may be neutralized by supply¬ 
ing bases where such bases do not occur 
in sufficient quantity. Examination has 
shown that the soils in many sections of 
the State are acid, and until this condi¬ 
tion is corrected the efficiency of fertil¬ 
izers applied to such soils will be limited, 
and as a result the crop-producing power 
of these soils will be lowered. Carbon¬ 
ate of lime in the form of finely ground 
limestone has been found well adapted 
for this purpose. 
When sulphate of ammonia is placed in 
the soil as a fertilizer, nitrification takes 
place, and the ammonia, in the form 
of a nitrate, is either used by the 
plant or lost in the drainage waters; 
while the acid radical which we call sul¬ 
phuric acid is left free to unite with a 
base, such as lime (in which case gyp¬ 
sum or land plaster would be formed). 
However, if not enough bases are present, 
the acid condition of the soil is increased. 
This has been well demonstrated at the 
famous Rothamsted Experiment Station 
in England, where certain plots were con¬ 
tinually fertilized with sulphate of am¬ 
monia for years, finally becoming almost 
non-productive, while on land previously 
treated with lime or marl the annual ap¬ 
plication of sulphate of ammonia has not 
had this effect. In commenting on this 
work, Dr. Hall, director of the station, 
says: “The long continued use of man¬ 
ures like the ammonium salts, which are 
effectively acids, must have altered the 
reaction of the soil and made it sour. 
This is very palpable on the plat 
which has received a very heavy 
dressing of ammonium salts alone, and on 
which there is now a large amount of sor¬ 
rel, except upon the small portion where 
the chalk had been applied.” Doctors 
Hall and Miller speaking of one of the 
fields on the farm of the Royal Agricul¬ 
tural Society at Woburn, which has been 
under experiment since 1876, say: “The 
amount of calcium carbonate present is 
exceedingly small, barely determinable in 
fact, yet the plats continue to yield nor¬ 
mal crops, except those which have been 
manured with ammonium salts. The lat¬ 
ter, in recent years, have become almost 
sterile, showing an acid reaction to litmus 
paper, and refusing to grow wheat or 
barley, unless they first receive a dress¬ 
ing of lime.” 
At no other place in this country has 
so much work been done on acid soils as 
at the Rhode Island Station, and in one 
of the reports from that station Dr. 
Wheeler says, “One fact has been fully 
established—that sulphate of ammonia if 
not applied in connection with lime or 
other substances capable of neutralizing 
or overcoming the natural acidity of the 
soil, further increases the injurious action 
