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Soil & Pedology
The soil.
Pedogenetic factors.
Pedological horizonts.
Pedology.
The soil represents a natural resource impossible to be replaced or
renewed (or renewable only in a long time) which has been often
undervalued and exposed to a partial or total loss risk. Undoubtedly
this natural body constitutes a huge heritage in a scientific and
cultural sense.
The
soil, as a surface part of the earth crust, is a natural, dynamic
and indipendent body composed of mineral particles and containing
organic matter and It is subjected to its own evolution laws. It has
a specific morphological organization due to particular pedogenetic
processes produced and ruled by different elements and factors.
This natural body supporting or able to support a vegetation, is
composed of "horizons". A lot of these horizons can be subdivided in
subhorizons and constitute the pedologic profile in their whole. The
scientific dicipline that takes an interest in these problems is
called "pedology" , or "soil science".
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The main pedogenetic factors are represented by the lithological one
(or better by the pedogenetic substratum) by climate (thermo-pluviometric
regime) , the relief (altitude, exposure, slope) the direct action
of the organisms (vegetables and animals, man included) and by the
time (in consideration of the long periods necessary for completing
the pedogenetic process).
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Horizons are mineral and/or organic strata of varying thickness,
differing among themselves and from the lithologic substratum for
some morphologic, physical, chimical and mineralogic properties and
for biological features. They are pointed out by initials so to have
throughly: O, possible organic horizon; A, horizon containing either
organic matter, decomposed and humified, or mineral substances
resulting from disgregated and alterated rock; E, horizon
impoverished of soluble chemical compounds and those removable in
suspension such as clay; B, horizon rich of alteration minerals or
where some elements from E horizon are concentrated; C, horizon
composed of “soft” substratum or disgregated rock; R, “hard” and not
alterated rock.
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The first purpose of Soil Science is the comprehension of the
mechanisms and the processes by which in a certain period of time
fragments of rock change in a material able to support a vegetation
and then in a mature ground, through the actions of the
environmental factors, like the direct intervention of the
atmospheric agents and the living organisms or the indirect one of
the geological and morphological conditions.
The
soil records and preserves the trace of climatic variations , floods
and human interventions that have determined the characteristics
currently possessed not only from the ground, but from the whole
territory.
The
Soil Science investigates also on the physical , morphological,
chemical, and biological characteristics of the soils to carry out
their classification and cartography.
After concluding the first phase of the study with the collection of
naturalistic ard technical-scientific informations on the soils, a
series of elaborations is beginning to provide maps and reports for
planners about the characteristics of the land interpreted on
pedological data.
Among the different types of land classification for agrarian
purposes, the "Land Capability" system, elaborated by the Soil
Conservation Service (U.S.D.A.), is the most broadly applied in many
countries. For the planning of particular employments of the
territory, in order to adapt the choice of the zones on which
intervene in according to their natural vocations , it's useful to
adopt the "land suitability" system, that gives the evaluation of
the soil attitude for a defined use, in our case Land Suitability
for the truffle.
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