Justus von Liebig (1803 -1873)

Law of the

Minimum

Briefly explain the “law of the minimum”.

What is a soil pedon ?

Brady and Weil, 2002

Briefly explain any 2 of the soil body metaphors that we discussed in class

Textural triangle

12 textural classes

http://www.oneplan.org/Images/soilMst/SoilTriangle.gif

How much sand, silt and clay is represented by this location ?

Why do the textural class zones on the textural triangle have such strange sizes and shapes ?

Soil = f (Cl, O, R, P, T…)

H Jenny refined the ideas of Russian scientist VV Dokuchaev into the following equation:

Identify the 5 factors of soil formation

Hans Jenny(1899 - 1992)

Mendocino Staircase

Why did Dr. Jenny think the Mendocino staircase was such as interesting

place?

a) Identify 4 soil functions.

b) Which soil function is of greatest interest to you ? Explain.

Bedrock geology is very important to well drillers in IL but is not very important to soil scientists. Briefly explain.

Interstream divide

SOIL DRAINAGE CLASSES

Poorly drained

Somewhat poorly drained

Moderately well drained

Poorly drained

Well drained

Valley floorBackslope

Shoulder

LANDSCAPE POSITIONS

N.C. Agric. Res. Bull. 467

Common in IL

Briefly explain why the landscape position identified by the oval is poorly

drained (without artificial drainage).

Young Soil in NC

Old Soilin NC

http://www.mo15.nrcs.usda.gov/features/gallery/

Describe 2 differences (other than color) that are generally expected between

“mature” and “immature” soils.

a) Identify 3 of the 4 types of soil forming processes illustrated on this diagram

Adapted from Stewart (1990)

b) Provide a specific example for 2 of the processes

http://www.fnps.org/photos/spodosol.jpg

Typical Florida flatwoods Spodosol

a) What is the name of this horizon ?b) What is the name of the water driven process from which this pale colored and weak structured horizon derives its name ?

C…. T…… D……

S……..C……….

O…… …… ……. A……

M…… …………. B……… ……..

C…. T…… D……

S……..C……….

O…… …… ……. A……

M…… …………. B……… ……..

Identify 3 soil properties that are commonly used to differentiate soil horizons

o O

Briefly explain why many soils in IL do not have all 5 of the master horizons.

Should we maintain long term experiments ? Explain your answer.