HomeMy WebLinkAbout1620 e brundage _envirotech report 6.22.20_114-126Si SuyAad �"�� Me How ����00 ������ m ��
Soil surveys are made to provide information about the soils and miscellaneous
areas inaspecific area. They include a description of the soils and miscellaneous
areas and their location on the landscape and tables that show soil properties and
limitations affecting various uses. Soil scientists observed the steepness, length,
and shape of the slopes; the general pattern of drainage; the kinds of crops and
native plants; and the kinds of bedrock. They observed and described many soil
profiles. A soil profile is the sequence of natural layers, or horizons, in a soil. The
profile extends from the surface down into the unconsolidated material in which the
soil formed or from the surface down to bedrock. The unconsolidated material is
devoid of roots and other living organisms and has not been changed byother
biological activity.
Currently, soils are mapped according to the boundaries of major land resource
areas (MLRAs). IVILRAs are geographically associated land resource units that
share common characteristics related to physiography, geology, c|imote, water
naaourcee, soi|e, biological naaounoem. and land uses (USDA, 2008). Soil survey
areas typically consist of parts of one or more PNLFA.
The soils and miscellaneous areas in a survey area occur in an orderly pattern that
is related to the geology, |andformo, relief, o|imete, and natural vegetation of the
area. Each kind of soil and miscellaneous area is associated with a particular kind
of|ondformor with e segment of the |endfonn.By observing the soils and
miscellaneous areas in the survey area and relating their position to specific
segments of the landform, a soil scientist develops a concept, or model, of how they
were formed. Thus, during mapping, this model enables the soil scientist to predict
with a considerable degree of accuracy the kind of soil or miscellaneous area at a
specific location on the landscape.
Commonly, individual soils on the landscape merge into one another as their
characteristics gradually change. To construct an accurate soil map, however, soil
scientists must determine the boundaries between the soils. They can observe only
a limited number of soil profiles. Nevertheless, these observations, supplemented
by an understanding of the soil-vegetation-landscape relationship, are sufficient to
verify predictions of the kinds of soil in an area and to determine the boundaries.
Soil scientists recorded the characteristics of the soil profiles that they studied. They
noted soil color, texture, size and shape of soil aggregates, kind and amount of rock
fnagmonta, distribution of plant noota, reaction, and other features that enable them
to identify soils. After describing the soils in the survey area and determining their
properties, the soil scientists assigned the soils to taxonomic classes (units).
Taxonomic classes are concepts. Each taxonomic class has a set ofsoil
characteristics with precisely defined limits. The classes are used as a basis for
comparison to classify soils systematically. Soil taxonomy, the system of taxonomic
classification used in the United States, is based mainly on the kind and character
of soil properties and the arrangement of horizons within the profile. After the soil