For purposes of classification, the lower boundary of soil is arbitrarily set at ?? below the surface 1.

For purposes of classification,

the lower boundary of soil is arbitrarily set at ?? below the

surface

1

What are the 6 levels of USDA Soil Taxonomy?

__a_____b_______C________d____

____e____

How many?

Which level is named after the place where it was first identified?

2

Diagnostic sub-surface horizons

Why does USDA Soil Taxonomy place so much emphasis on sub-surface diagnostic horizons?

3

What is the soil order ? “new soils”

sands, river bottoms

4

What is the soil order? “immature soils”

Which master

horizon is just

starting to form in this soil?

5

The central concept of ????? is that of soils with an argillic, a kandic, or a natric subsurface diagnostic horizon and a base saturation ≥ 35%

“fertile forest soils”

What is the soil order?

Thin A horizon

well developed B horizon

weak E horizon

rich in Ca and Mg

6

What is the soil order? “red and yellow acid soils”

Only recently mapped in southern IL

strongly developed B horizon

distinct E horizon

Thin A horizon

low in Ca and Mg

7

What is the soil order? “black prairie soils”

thick A horizon(s)

well developed B horizon

8

What is the soil order?“muck or peat soils”

9

Richter and Markewitz (2001)

a b c d

Identify the soil orders (labeled a,b,c and d)in this conceptual chronosequence

E

10

Geographic extent of the Drummer soil series

Family = Fine-silty, mixed, superactive, mesic Typic Endoaquolls

What is the soil order?11

What is the soil order?

12

What is the hue of the Ap horizon?What is the chroma of the Bt1 horizon?

13

What is the term for “soils that are found together”?

NCSU Soils technical bulletin 314

14

What is soil micromorphology ?

15

Matric forces

+

a + b

Soil Skin

16

a

b

What is the name of the soil water

status when all the water susceptible

to the pull of gravity has drained?

Identify realistic soil

water tensions in bars or kPa for points a and b on this

diagram

17

H20

H20

H20H20

Just like a ball rolling down hill, water molecules

travel upward through plants

when the water tension along the path from soil to the atmosphere is increasingly

negative

b

a-0.3 bars

Identify realistic soil

water tensions (in bars) for

points a and b on this

diagram

18

Soil water is a switch that activates or deactivates soil biology

Water is considered biologically available, when soil organisms are able to win the “tug

of war” with the soil

Is it harder or easier for

organisms to win the water tug of war in a salty soil.

Briefly explain.

19

What is the purpose of a characteristic curve?

What is the volumetric

water content at field

capacity in the soil

represented by this curve?

If the rooting depth is 100 cm, how many cm of water are plant available in this soil?

20

Which texture can hold the most water?

Available water

Brady and Weil, 2002

Which texture can hold the most plant available water?21

At what soil water tension (in bars) would you want to start irrigating a tough crop like corn growing in a clay soil ?

Wimpy crops

Tough crops

Critical moisture levels to avoid crop stress

22

How does a gypsum block soil moisture sensor

work?

23

Coarse textured layer

Fine textured layer

How does the presence of a coarse textured layer under a fine textured layer affect percolation ?

Be sure to explain your answer.

24

Briefly discuss something interesting related to soil that you learned about in the last month that you have not yet discussed on this quiz.

25