Download Soil Survey

Lecture 8a
Soil Survey: An Inventory of the Soil Resource
3 Main Elements
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1) a map showing the geographic relationships of each soil
2) a text describing the soils
3) tables giving physical and chemical data and
interpretations for various uses.
Soil Survey
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A soil survey:
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describes the
characteristics of the
soils in a given area,
usually a county is the
unit of publication.
The survey classifies
the soils according to a
standard system of
classification,
plots the boundaries of
the soils on a map, the
map uses an aerial
photo as the base
Makes predictions
about the behavior of
soils,
House
Tree
soil boundary
Trees
Soil Survey
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The different uses of
the soil and how
management affects
them are considered,
The information
collected in a soil
survey helps in the
development of landuse plans,
The Survey evaluates
and predicts the
effects of land use on
the environment.
Map Scale
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Soil maps differ in their
scale:
Map scale refers to how
many inches on the map
represents inches on the
ground 
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Scale of 1:24,000 says 1 inch on
map = 24,000 inches on the
ground.
Or 1” map = 24,000” ground
24,000”/12”/ft.=2000 ft.
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Or 1 inch = 2000 ft &
/5280ft/mile = 0.38 miles.
Note:1 mile =63,360 inches
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3 in x 24000 /12 = 6000ft
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Topographic Map
Scale = 1:24,000
(----3IN--)
Making a Soil Map
1. Soil maps are not road
maps
- soils boundaries are
interpreted and the line is
placed on the map by the
soil scientist
-the lines on the map
represent their
interpretations of where
the soil boundary changes.
- these lines are
determined by
investigating the soil with a
hand auger or power auger
- the use of remotely
sensed data ( air photo) will
also help in determining
where these lines are
placed.
2. Thus the only
accurate soil map has
a scale of 1:1 but that
is not possible.
3. Soil maps are
approximations of the
soil boundary location
- road maps have
more precise
accuracy.
4. Soil maps are
checked for accuracy
by running transects
(red & blue lines)
across the mapping
units.
Transects in red & blue
Soil Mapping Units –
2 kindsConsociation & Complexes
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PwA = Port Byron soil on A slope
(0-2%)
Soil maps done in the recent past use
numbers for the map unit – ie 285A = Port
Byron on 0-2% slope
SdC2 = Surrey & Dim soils on C
slope (6-12 %)
Consociation - 75% named soil & 25
% inclusions
Complexes - 2 or 3 named soils =
75% & 25 % inclusions of unnamed
soils
Rectangular Legal Land Description
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Metes and Bounds
Description– describe the
property by noting the
location of known objects
(tree, rock, river)– Can be
a problem when the
object is no longer there.
13 original states and
Spanish land grants
Rectangular – describe
the property from the
intersection of a meridian
and base line using
Townships of 6 square
miles. Each section in a
township is one square
mile or 36 sections in a
township.
US Meridans and Base Lines
T1NR1E
Legal Land Description
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Every property has a
legal land description
that give the location of
the property from
smallest to largest.
Largest = Town and
Range – location from
principal base line and
meridian T6NR4E.
Section 1-36 each a
square mile or 6x6
Location in Section as
NW1/4 of the SE1/4
LEGAL LAND DESCRIPTION:
NE¼, SEC 22, T2 North; R3 East
of 4th Meridian
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Largest = Town
and Range –
location from
principal base line
and meridian by
townships,
T6NR4E.
Section 1-36
each a square
mile or 6x6
Location in
Section as
NW1/4 of the
SE1/4
Orders of Soil Survey
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Order 1 soil
survey - very
detailed
Order 2 = regular
soil survey
Order 3 = US
forest survey
Order 4 = general
soil map of county
Order 5 = soils of
Minnesota Map
DYAD
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Have you ever used Legal Land Description?
If so where?
What about metes and bounds?
If answer is no to the above two, describe your seat in this classroom from the front door of Borlaug Hall using Mets and Bounds.
NRCS Web Based Soil Survey Information System
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WEB SSIS provides the
information in the soil survey
via the internet.
Thus it is easy to quickly
check the capability of the
soil for a specific use.
Web Soil Survey found at
http://websoilsurvey.nrcs.usda
.gov/app/
Sample from Lab; Sec 8, T114
R 28W- 5th pm -
Maintenance Schedule for Web Soil Survey 2.2
Web Soil Survey is unavailable nightly between 1:00 AM and 5:00 AM
Eastern time for soil survey data updates.
Web Soil Survey may be unavailable on Tuesdays and Thursdays
between 8:00 PM and 10:30 PM Eastern time for scheduled
maintenance and software updates.
Web Soil Survey may also be unavailable the third weekend of each
month, and the second Sunday of each month, for scheduled maintenance.
It may also be necessary from time to time to bring Web Soil Survey down
for unscheduled maintenance.