FLORIDA STATE HORTICULTURAL SOCIETY 
55 
soils is the reverse. The soil is made more 
compact and the particles are more or less 
loosely cemented together. This permits 
of the soil drawing subsoil water higher 
and faster in time of dry weather, and by 
checking somewhat the movement of air 
through the soil tends to a slower oxida¬ 
tion of humus. By always plowing to a 
certain depth a lime pan may be formed— 
a layer somewhat impervious to the down¬ 
ward movement of water, thus reducing 
or checking to some extent the loss of 
plant foods, chiefly nitrates, by leaching. 
The first chemical effect of lime when 
applied to the soil is probably the neutral¬ 
izing of free acids in the soil, forming in¬ 
organic or organic salts of lime as 
the case may be, thus producing a 
neutral or slightly alkaline condition 
of the soil water, according as 
lime is applied in sufficient amount or 
in excess of the requirement. Just what 
the different effects upon the crop in satis¬ 
fying the soil as regards lime may be is a 
somewhat difficult proposition to answer 
specifically. We will speak of this phase 
in considering the biological effects. Suf¬ 
fice it to say that Blair and Macy conduct¬ 
ed experiments which showed that 68 per 
cent of the soils showed by the lime water 
method an average requirement of about 
one and one-half tons of carbonate of lime 
to the acre nine inches of soil. Experi¬ 
ments with beggar weed showed a gain, 
with the use of lime, of 17 per cent green 
weight and 20 per cent dry weight, while 
on acid muck soil ground limestone in¬ 
creased the yield 120 per cent dry weight. 
A second chemical effect of liming is 
the liberation of plant food by the chem¬ 
ical interchange of free lime with potash 
which is held in absorption by certain zeo- 
litic materials and the humus in the soil. 
By this interchange the soluble lime be¬ 
comes insoluble and the insoluble potash 
becomes soluble and available. By means 
of the absorptive power of soils the farm¬ 
er, if he puts on potash as a fertilizer in 
excess of the immediate requirements of 
the crop, does not lose it, but is able by the 
aid of lime to reap the benefits steadily 
throughout the season. Otherwise, the 
best method of applying fertilizers would 
be a much more complicated one. 
Applications of phosphoric acid in the 
form of super-phosphate is also beneficial¬ 
ly affected by lime. Let us suppose we have 
incorporated in the soil a ton or two of 
lime, which by the action of rain and soil 
moisture together with carbonic acid has 
been thoroughly disseminated through the 
soil and coats more or less all of the soil 
grains with a thin layer of lime. Then we 
apply the super-phosphate, the rain dis¬ 
solves the soluble or monocalcium phos¬ 
phate and carries it in solution all through 
the soil, but does not wash it out because 
what is not taken up immediately by the 
plants comes in contact with this layer of 
lime surrounding the soil grains and is 
taken out of solution by a chemical pro¬ 
cess called reversion, so that it coats more 
or less all of the soil grains with dical¬ 
cium phosphate or reverted phosphate, 
which, though it cannot be leached out of 
the soil, is gradually available 'to the 
plant. This gives a more perfect dissem¬ 
ination of phosphoric acid than is pos¬ 
sible with any form not water soluble. 
If, now, we had not applied lime and the 
