land-use scorecard

Land-Use ScorecardLandscape Characteristics

Percent Slope

-Percent slope is the rise and fall in 100 feet.

-Subtract the difference between the two heights and multiply by 4 if taken at 25 feet.

Landscape CharacteristicsPercent Slope

0-2 % Nearly level2-5% Gently Sloping5-10% Moderately Sloping10-15% Strongly Sloping15-20% Moderately Steep20-30% SteepMore than 30% Very Steep

Thickness of Plow or Surface Layer, Degree of Erosion & Deposition

Directly related to % slopeMeasure from the top of the profile down

to where the subsoil starts8” to 20” deposition (more likely 20” to

60”)This will be the lowest of the sites, likely

near a ditch or streamThe entire profile is topsoil, the lower half

will be darker than the upper half

Thickness of Plow LayerMore than 9”, no evidence of subsoil

mixing; none to slight erosion3” to 9”, may have up to 50% subsoil

mixing; moderate erosionLess than 3”, plow layer may be

mostly subsoil; severe erosion8” to 20” deposition layer of different

color or texture than buried surface soil

Soil Profile Characteristics

Color and percent of organic matter in plow (surface) layer

Moisten 2 inches from the top-get some moistened soil on the color chart chips and match the nearest chip

See chart next slide

ColorVery darkDarkModerately darkLightVery light

Ave. % O. M.53 ½2 ½21 ½

Organic Matter Content

Presence of Grayish E HorizonA 2”to 6” layer between the topsoil &

subsoilPrimarily found in forest soilsIf WET it will appear as a grayish,

ashy, pasty materialIf DRY it will be a reddish brown,with

a platy structure

Soil Profile Characteristics

Grayish E horizon presentGrayish E horizon not presentNote: A2 horizon was its previously

known letter designation

Soil Profile CharacteristicsSubsoil color

Measure from the top of the profile down to 24”

If there are gray mottles above 24” it will be gray and brown mottled

If there are gray mottles below 24” will be brown or yellowish brown; gray or gray mottling below 24”

If there are NO gray mottles in the subsoil it will be brown or yellowish brown; no gray mottling

Note: Don’t confuse Gray substrata with Gray subsoil

Subsoil Color

Soil Profile Characteristics

Texturea. Fine-textured a ribbon forms

easily and remains long and flexible.

b. Moderately fine-textured a ribbon forms but breaks into pieces ¾ to 1 inch long.

c. Medium-textured no ribbon forms. The sample breaks into pieces less than ¾ inch long. The soil feels smooth and talc-like.

d. Moderately coarse-textured no ribbon forms. The sample feels gritty and lacks smoothness.

e. Coarse-textured no ribbon forms. The sample is composed almost entirely of gritty material and leaves little or no stain.

Texture (cont.)

Soil Profile Characteristics

TextureWet CLAY (fine texture) will leave a

“stain” on your handsA profile with NO TRUE TOPSOIL

could have a moderately fine topsoil and a moderately fine subsoil

TexturePeat & muck soils will be very black

with black dust that leaves black on your fingers & it’s spongy to walk on

Substrata-first determine if it is present

Go to the bottom 1 foot of the profile = is the soil a different texture or color than the subsoil?

TextureSubstrata is usually gray-moist-pasty-

has no structure-will not break on even planes-no roots, and no dark coatings. It is highly that this type of substrata has a medium texture

A reddish tinted soil at in the bottom foot that ball & bounces easily will have a fine texture

TextureIf the texture in the bottom foot is the

same as the subsoil texture = the substrata in not present

Soil StructureTypes of Soil Structure

Single grain = sandMassive = won’t happenGranular = plowlayer (if it’s not a

true topsoil)Platy = clods come out of the profile

more Horizontal than Vertical

Soil Structure (cont.)

Blocky = (subsoil) clods break on irregular shape planes

Prismatic or Columnar = clods come out of the profile more Vertical than Horizontal

Soil Structure

A plowlayer with NO TRUE TOPSOIL could easily have a Blocky structure

Determine Structure by how the clods chip out of the profile walls.

Associated Soil Features

Internal Drainage and AerationThis is a DIRECT MATCH with your

SUBSOIL COLOR selection.If you miss Subsoil Color your also

going to miss Internal Drainage & Aeration.

Internal Drainage and Aeration

Example: If you choose a Gray and Brown mottled for you subsoil color than you will choose Somewhat poorly drained for your internal drainage and aeration.

Surface RunoffCombine the finest of the topsoil/subsoil

Textures with the % Slope on the front #I.Use Table #1 to determine the surface

runoffArea subject to ponding = will this be the

last spot where water drains after a rain?Area subject to flooding = this area must

be next to a continuous running stream.

Permeability

The ease of water and air movementMatch with Subsoil texture:

Rapid = coarse / moderately coarseMedium = medium / moderately fineSlow = fine or bedrock

Soil Depth

Measure to the lowest rootsBedrock is the only thing that will

cause the soil depth to be shallow

Available Water Holding Capacity

Use Table #2Use a 60 inch profile If you can only see the A and B

horizon then add the two thicknesses of each horizon and subtract the total from 60 to get the C horizon.

Usually very high in Central Illinois

Figuring C-Value

Given: % Slope Slope Length Z FactorThe percent slope in NOT the site’s

actual % slope. The C-Value information does NOT necessarily pertain to the site.

C-Value Procedure1. Combine the % Slope and the slope

Length on Table #42. Take the Table # 4 number &

divide it into Z. (Z always goes in the calculator first)

3. Just write down the first two numbers past the decimal point and drop all other numbers. (do not round up)

Procedure (cont.)

4. The answer you get by dividing is the C-Value.

5. On each of the five horizontal rotation/tillage choices = X the exact C-Value number or the next LOWEST number.

Procedures (cont.)

In order for YES to be checked for restricted use = you must have checked all four rows as DOES NOT APPLY

If C-Value is .02 or higher = NO will always be checked for restricted use

Nonagricultural UseUse Tables 6 (Home site) & 7 (Septic

Tank)O = None to SlightM = ModerateS = SevereYou must have filled the scorecard out

first in order to record this information. Look up the information from your scorecard.

Nonagricultural Use

The only difference between the two charts is that “somewhat poorly drained” for home site is considered moderate but “somewhat poorly drained” for septic tank is considered severe. All the other answers will be the same for both.

Degree of Limitation

You just place an X for the highest degree used in the home site and the highest degree used for the septic tank.

Severe is the highest, Moderate is second and Slight is the lowest degree of limitation.