This unit will look at two systems of classifying land: 1) Legal Land Description and 2) Land Capability Classification.
The metes and bounds system was used in the areas that were settled while the U.S.A. was still a colony of England, Spain or France. These areas are mainly in the East, or in Spanish land grants in the southwestern United States.
These descriptions start at some point on the boundary of a tract (usually a corner) and describe the direction and distance to the next corner. Then, a new direction and distance are given to another corner, and this continues all the way around the tract, back to the point of beginning. Prominent rocks, trees, roads, etc., serve as corners or boundaries. Irregularly shaped tracts and loss of markers as time passes may cause many boundary disputes under this system.
In 1875, the US adopted the rectangular survey system, which is used in 30 of the 50 states. This system is based on meridians (north-south lines parallel to lines of longitude) and baselines (east-west lines). There are 34 "principal meridians" in the United States; each has a baseline associated with it.
Land descriptions in Minnesota are related to the 4th principal meridian for areas east of the Mississippi River. This meridian intersects its baseline at a point near Dubuque, Iowa. Areas west of the river use the 5th principal meridian, which intersects its baseline in east central Arkansas.
See the Principal Meridian Map for a look at how Minnesota is divided for legal land description.
Tracts of land, called townships, are laid out beginning from the point
where the meridian crosses its baseline. Townships are as close to 6 miles
square as possible, but are about 50 feet shorter on the north side than
on the south side because of the curvature of the earth.
The legal description for a township gives a count of the number of townships (or tiers) north or south of the baseline to the one that includes the area being described. Thus, any area between 1 and 6 miles north of the baseline is town 1 north (T1N) and if a town is between 24 and 30 miles north of the baseline it would be in T5N (township five north).
The distance east or west of the meridian is similarly described in terms of ranges. An area 7 miles east of the meridian would be in R2E (range two east, from 7 to 12 miles east of the meridian).
If you are unfamiliar with how this might look, go to Legal Land Description to get an idea of how townships are counted.
The distortion caused by the curvature of the earth requires certain adjustments to be made. Correction lines are laid out at 24 mile intervals (4 townships) from the baseline.
Townships are measured 6 miles wide along each correction line but become narrower to the north until the next correction line is reached. Similarly, guide meridians are laid out every 24 miles east or west of the principal meridian. The guide meridians are broken at the correction lines. Townships are subdivided into 36 sections that are each one mile square, except that the size of the sections along the north and west sides of a township are adjusted in size where necessary to compensate for the earth's curvature.
The sections are numbered from 1 to 36, beginning in the northeast corner. Each one mile square section contains 640 acres. Areas smaller than 640 acres are described as portions of sections. These portions are normally described in terms of quarters or halves. The description written using this system is always from smallest to largest (for example: the southeast quarter of the northwest quarter of section 10, T5N, R2E). Most section corners were marked by stones with grooves scratched in two sides. The number of grooves designated the number of miles to the north and east township boundaries. More recent surveys used pipes capped with brass markers in place of the stones.
Your lab book and the computer program "Soil" have additional exercises to practice at using Legal Land Description.
The criteria used in grouping the soils do not assume major and generally expensive landforming that would change slope, depth, or other characteristics of the soils, nor do they include possible but unlikely major reclamation projects.
Capability classification is not a substitute for interpretations designed to show suitability and limitations of groups of soils for rangeland, for woodland, and for engineering purposes.
In the capability system, soils are generally grouped into:
1) capability class
2) subclass
Capability classes, the broadest
groups, are designated by Roman numerals I through VIII. The increasing
numerals ( I - IV and VI -VIII ) indicate progressively greater limitations
and narrower choices for practical use. Class V is a special case as described
below. The classes are defined as follows:
Class I soils have few limitations that restrict their use.
Class II soils have moderate limitations that reduce the choice
of plants or that require moderate conservation practices.
Class III soils have severe limitations that reduce the choice
of plants or that require special conservation practices, or both.
Class IV soils have very severe limitations that reduce the
choice of plants or that require very careful management, or both.
Class V category not related to slope, soils are not likely
to erode, but they have other limitations, impractical to remove, that
limit their use. These limitations could be flooding, stones, large boulders
or shallow soils with bedrock close to the surface.
Class VI soils have severe limitations that make them generally
unsuitable for cultivation.
Class VII soils have very severe limitations that make them
unsuitable for cultivation and only can be used for range or forestry.
Class VIII soils and miscellaneous areas have limitations that
nearly preclude their use for any production and are often just used for
recreation.
Capability subclasses are soil groups within one class. They are designated by adding a small letter, e, w, s, or c, to the class numeral; for example, IIe.
The letter e shows that the main hazard is the risk of erosion unless a close-growing plant cover is maintained; w shows that water in or on the soil interferes with plant growth or cultivation (in some soils the wetness can be partly corrected by artificial drainage); s shows that the soil is limited mainly because it is shallow, droughty, or stony; and c, used in only some parts of the United States, shows that the chief limitation is climate that is very cold or very dry.
There are no subclasses in class I because the soils of this class have few limitations. The soils in class V are subject to little or no erosion, but they have other limitations that restrict their use to pasture, rangeland, woodland, wildlife habitat, or recreation.
Class V contains only the subclasses indicated by w, s, or c. The capability classification of each map unit is given in the section "Detailed Soil Map Units" of the Soil Survey Report. To look at this go to Sherburne County Soil Survey - Isan Sandy Loam which is LCC Vw.
To view landscapes and soil of the various classes, indicate the appropriate Land Capability Class below.
Class I, Class II,Class III,Class IV,Class V,Class VI,Class VIII,orVIII
