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PHaroX'VeTcb 
Vol. LXVIII No. 3080. 
NEW YORK, FEBRUARY 6, 1909. 
WEEKLY, $1.00 PER YEAR 
WHY ARE LIME SOILS STRONG? 
Their Origin and Use. 
I am a little puzzled, and take the liberty of asking 
you to help me out. We are continually being told by 
agricultural writers that a limestone soil, that is, one 
containing lime rock or one containing pieces of broken 
limestone, is a good soil. 1, or anyone else, can 
observe that this is true, hut I have for a long time 
been waiting for some one to tell me just why this is so. 
Schuylerville, N. Y. T. e. b. 
It has long' been an adage that “a lime country is 
a rich country,” but the full zvhy this is so is yet a 
matter of many doubts. Pure science has much to 
reveal before conjectures can be wholly removed 
and before the how and why of lime in soil produc¬ 
tivity can be one of the generally recognized beacon 
lights in practical agriculture it is destined to be¬ 
come. And after pure science has done its work, 
applied science must needs construct the sailing 
which plays so important a part in determining the 
productive capacity of soils. 
HOW LIMESTONE AND LIME SOILS ARE 
FORMED.—Much of the more than 300,000 tons of 
lime carbonate leached out of soils and the underlying 
rocks and carried into the sea per each cubic mile of 
water is again laid down in the shallower waters 
off shore by coral and shell-forming animals, giving 
rise to broad stretches and thick beds of limestone 
material having entangled with it silts, sands and 
organic material in greater or less quantity. These 
limestone deposits when, by future upward move¬ 
ments of the earth’s crust, they come to be portions 
of the dry land, are again subjected to the processes 
of weathering, which carry back to the sea the bulk 
of the lime carbonate, leaving a stratum of over- 
lying soil rich in lime and usually other ■ essential 
soil ingredients. By the continent-wide glacier¬ 
grinding an immense amount of rock pulverizing 
other hand, in the soils of the Atlantic and Gulf 
coast, where glaciers have not operated, but where 
heavy rainfall and consequent leaching have pre¬ 
vailed for long periods, the soil content of lime 
carbonate is necessarily low, and for this reason 
such soils are naturally less productive than they 
could otherwise be. 
EFFECT OF LIME CARBONATE.—In outlining 
some of the ways in which lime carbonate tends to 
produce and to maintain rich soils it should be under¬ 
stood that when ordinary lime is applied to a field, 
whether it be ground or slaked, it is very soon 
converted into the lime carbonate by the union with 
it of carbonic acid from the soil or air, and the 
beneficial effects it is observed to exert are very 
largely those due to the lime carbonate thus formed. 
The only reason for applying burned or slaked lime 
to soils has been that until recently the burning of 
limestone and slaking it has been the cheapest 
A STEAM PLOWING OUTFIT IN THE GREAT CANADIAN NORTHWEST. Fig. 45. 
chart for the guidance of the farmer before he can 
be fully able to develop, conserve and utilize lime 
with the economy and high efficiency needful for 
continued crop production. Many of the facts and 
some of the underlying principles needful for the 
direction of practice are known and may be stated. 
THE SOURCE OF LIME IN SOILS.—All lime 
in soils is derived primarily from the primitive rocks 
by their reduction to fine fragments, or by their solu¬ 
tion, chemical and physical, and, on the average, 3.5 
pounds in every 100 pounds of primitive rock is 
calcium, one of the elements, as are iron, gold, car¬ 
bon, sulphur, oxygen and nitrogen, and this calcium, 
united with oxygen, is the lime of commerce, ob¬ 
tained by burning limestone in kilns. But when 
such rocks are broken down into soil and this is 
acted upon, as such, by Nature’s agencies, the lime 
dissolves out and is borne away in the drainage 
waters in immense volumes, so large that, on the 
average, each cubic foot of river water carries to 
the sea more than 2.1 ounces of lime compounds^ 
eight-ninths of which is lime carbonate, the basis 
of limestone, the chief ingredient which deposits on 
the inside of teakettles, and the lime compound 
and distribution took place in comparatively recent 
time. In this way limestone sections were over¬ 
swept, and much of the lime rock was broker^ 
ground and spread broadcast, deeply and intimately 
commingling the lime fragments with soil materials, 
thus producing soils rich in lime carbonate where 
otherwise such could not have been formed. This 
gigantic liming operation of Nature occurred too 
recently for the application to have been dissolved 
away, and we thus have wide areas of soils rich in 
lime not directly underlaid by limestone. Indeed, 
most of the northern United States, reaching from 
the Atlantic to the Rocky Mountains, and lying to 
the north of the Ohio River, is covered with soils 
richer in lime on account of this glacial action. In 
the arid and semi-arid regions of the world, where 
there is comparatively little leaching, nearly all soils 
may be rich in lime carbonate because, as the soil 
and rock decay under the conditions of scanty rain¬ 
fall, the lime carbonate produced tends to accumulate 
toward the surface under the influence of capillary 
rise and surface evaporation of the soil moisture, 
and so the soils of the western portion of the 
United States are nearly all rich in lime. On the 
method of getting the rock in a sufficiently fine 
powder so that a small amount may be spread over 
a large area, and so that a small quantity, by 
weight, of the lime carbonate has a sufficiently large 
surface upon which soil moisture may act and dis¬ 
solve it rapidly, for it is only after it is in solution 
that its effects in the soil are felt. One of the most 
important effects of an abundance of lime carbon¬ 
ate in soils is the influence it exerts in tending to 
bring about a bunching of the finest silt and colloidal 
particles of the soil into larger compound aggre¬ 
gates, thus making what might otherwise be a stiff,, 
impenetrable, impervious and untillable clay a deep, 
mellow, open, well-drained, well-aerated soil, rich in 
available moisture and available plant food, and in 
which the roots of plants will spread wide and deep, 
thus enabling a crop to be abundantly nourished 
when the absolute content of soil moisture and the 
available plant food may be relatively low. A 
smaller absolute content of moisture and .of plant 
food material will suffice for abundant crop feeding 
in a coarse sandy soil than is possible in a fine clay 
one, and simply because it has so much less sur¬ 
face upon which soil moisture and plant food can 
