Liming Soils 
R. E. Skinner 
Mr. President, Ladies and Gentlemen : 
Lime, king of soil amendments, has 
long been used as a means of soil im¬ 
provement, and the recognition of the 
agricultural value of certain forms of lime 
appears as far back as the writings of 
Pliny, which show that liming was prac¬ 
ticed by the Romans and Saxons more 
than two thousand years ago. The effects 
of lime on the history of the human race 
are well described by that great student 
of the soil, Professor Hilgard, as follows : 
England, France, Belgium, and most of 
western Europe are rich countries largely 
owing to their abundant limestone forma¬ 
tions, and it may be questioned whether 
had this been otherwise, Europe would so 
long have remained the center of civiliza¬ 
tion. 
Its use and popularity in agriculture, 
however, has not always been so general 
and prominent, as the old adage would in¬ 
dicate : “Lime maketh a father rich but 
a poor son.” The recent revival of inter¬ 
est in liming began about 1895, and since 
then much studying and experimenting, 
scientific and otherwise, has been done, 
giving rise to some theories, many prac¬ 
tices, and much uncertainty in its use. 
As a factor in plant growth, however, 
science has shown it to be a most impor¬ 
tant one. Prof. Fippin, of the Depart¬ 
ment of Soil Technology in Cornell Uni¬ 
versity, places it in order of importance 
before fertilizers, tillage and organic mat¬ 
ter, and second only to the factor of soil 
moisture. 
Interest was drawn to the study of lim¬ 
ing in this state about 1906, when the 
Agricultural Experiment Station pub¬ 
lished a bulletin (No. 87) on soil studies, 
followed two years later by another (No. 
93) on acid soils. These, through the 
knowledge gained by soil analysis, led to 
the belief that Florida soils are more gen¬ 
erally acid in character than had pre¬ 
viously been suspected. This leads us to 
inquire as to just what is the meaning of 
this phrase, “acid soil,” of recent years 
so prominent in agricultural literature, 
and yet perhaps there is no phase of the 
knowledge of soils so little understood, 
particularly by the layman. The phrase 
is a misnomer, used because no better 
term has yet been suggested. So-called 
soil acidity may be of two forms, active 
or negative acidity. The active acidity is 
induced by an actual acid in the soil. Such 
acid is invariably of the weaker or organic 
acids, as the stronger acids take to them¬ 
selves the basic material at hand. But 
any free acid soon drains away, so it is 
only where poor drainage occurs that any 
significant amount of active acidity is 
found. 
These tend in the processes of weather- 
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