Tutorial for "Soil Factors, Part 1"
left-hand-side of land judging card

To understand land judging you must first understand how a contest is set up

Preparing Field Sites
    Each site should have colored flags to indicate field boundaries of the area to be judged.  The fields should be a minimum of 100 feet x 100 feet in size, but it does not necessarily have to be square.  Two well-marked stakes should be placed 100 feet apart for contestants to use to determine slope.  These should be the same distance above the ground and as much as possible with the normal slope of the land.  A hole or trench must be dug to expose the depth of the soil profile.  It is best to use string to mark off an area in the trench as an "off limits area" that contestants use only to determine topsoil thickness and soil depth.  Representative topsoil and subsoil samples should be available in boxes and appropriately marked.  If the soil is very dry, a water bottle should be available to moisten soil samples.

    The field condition card at each field will give you enough information to fill out the fertilizer portion of a land card also information needed for other portions of the land card. The land judging cards we will be discussing are single field cards. But for state and national contest you will be using a four field carbon self-grading card. (261K)

Soil texture refers to the relative proportion of sand, silt, and clay particles in a specific soil mass. It is easiest to determine when the soil is moist. Sand feels gritty when rubbed by the finger. Silt feels slick or velvety. Clay is usually sticky and plastic when wet and when pinched between the thumb and finger forms a flexible ribbon.

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Soil Texture by Feel  

The surface texture is normally determined from at least plow depth or 6 inches, however, erosion may have removed the surface to such an extent that only 1 or 2 inches may remain. For contests, a boxed sample of surface soil and subsoil will be provided to judge texture.

In soils, several subdivisions of texture are recognized and are illustrated below. For land judging we recognize five texture categories represented by the middle column of the accompanying table.

Coarse-textured soils are loose, very friable, and the individual grains can be readily seen or felt. When squeezed between thumb and forefinger, it feels gritty and will not ribbon or stain fingers. Squeezed when dry, it will fall apart as pressure is released. When moist, a mold may be formed which is unstable and crumbles as the soil is handled.

Moderately coarse-textured soils feel gritty but contain enough silt and clay to make moist soil hold together. The individual sand grains can readily be seen and felt. Squeezed when dry, it will form a mold which breaks readily upon handling. If squeezed when moist, a mold can be formed which can be carefully handled without breaking. It forms no ribbon or very poor ribbon.

soils have a slightly smooth or velvety feel when moist. Squeezed when dry, it forms a mold that will bear careful handling. The mold formed by squeezing when moist can be handled freely, without breaking. When the moistened soil is squeezed out between thumb and forefinger, it will form a poor ribbon with a dull surface.

Moderately fine-textured soils usually break into clods or lumps when dry. When the moist soil is squeezed out between thumb and forefinger, it crushes with some effort. It will form a short (1 inch to 2 inch) well-formed ribbon with a shiny surface which will tend to break or the ribbon will bend downward. The sandy clay loam texture has a slightly gritty feel when moist.
Fine-textured soils form very hard, massive lumps or clods when dry and are quite plastic and sticky when wet. When the moist soil is squeezed out between thumb and forefinger it crushes with considerable effort and will form a long (2 inch+) ribbon which will support itself. The sandy clay texture may also have a slightly gritty feel when moist.

Depth of Soil
In determining depth of soil you will measure from the designated bottom of the subsoil to the top of the hole. You will check the box that represents this measurement.

    If the measurement is 40 inches or greater the hole is deep.
    If the measurement is between 20 and 40 inches the hole is moderately deep.
    If the measurement is between 10 and 20 inches the hole is shallow.
    If the measurement is less than 10 inches the hole is very shallow.


    Flags are 100 feet apart (A and B). From the approximate center of the 100 feet(C), step 15 steps toward to the low side of the slope. (D)With a straight edge or using your arm extended at the ground level of (A), swing your body keeping straight edge or your arm level, locating point (E) directly above flag (B). The measurement of (E) to the ground is percent or foot of fall in elevation from (A) to (B).

If elevation fall is less than 1 foot the slope is nearly level.
    If elevation fall is between 1 and 3 feet the slope is gently sloping.
    If elevation fall is between 3 and 5 feet the slope is moderately sloping.
    If elevation fall is between 5 and 8 feet the slope is strongly sloping.
    If elevation fall is between 8 and 15 feet the slope is steep.
    If elevation fall is greater than 15 feet the slope is very steep.

    Using the original topsoil number on field condition card you determine where the topsoil meets the subsoil. From the designated location in the hole dug for that field. The number of inches from the top of the subsoil to the top of the topsoil is your current topsoil measurement. The fraction you make by putting current topsoil over original topsoil will determine which box you check on your land card.
    If the fraction is 3/4 or greater erosion is none-to-slight.
    If the fraction is between 1/4 and 3/4 erosion is moderate.
    If the fraction is less than 1/4 the erosion is severe.
    If the fraction is less than 1/4 and you have uncrossable ditches the erosion is very severe.

    This is determined by your subsoil.
    A coarse subsoil means rapid permeability.
    Moderately coarse and medium subsoils mean moderate permeability.
    Moderately fine means slow permeability. 
    Fine subsoil means very slow permeability.

Surface Runoff
    This is determined by slope and or surface texture and or permeability.
    A slope of 3 feet or great means rapid runoff*.
    Gentle sloping means moderate runoff*.
    Nearly level slope means slow runoff*.
    Very slow permeability concave type slope will be very slow runoff.
*Coarse surface texture and rapid permeability will be very slow no matter what the slope;
but will not be counted as a major factor

Major Factors that keep land out of Class I look at the boxes that you have checked . If the red number to the left of that box is anything but 1 check that as a major factor (except a coarse surface texture and rapid permeability which causes very slow runoff. Runoff will not be a factor.)





Land Capability Class
    The highest red number to the left of the boxes will be the number you put for land capability class.*

*Different combinations of factors can cause the land class to go lower. We will discuss these combinations later.

Conditions that will not be used in contest:
shallow or very shallow coarse textured soils or
nearly level slopes with moderate erosion.

Recommended Land Treatments, Part 2