Soil Science WEB Exam 3 Fall 2007 Dept. of Soil, Water and Climate
Directions 1. There is ONE BEST answer per question. 2. Place your answers on answer sheet, you only need to turn in the answers.
Name ______________________________________
1.________ 2._______ 3._________ 4._______ 5.______ 6._______ 7._________ 8._______
9.______ 10._______ 11. _________ 12.________ 13.______ 14.________ 15._________
Total _____
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15 Questions
1. The soil structural peds that are in the
picture # 1 are called____?____
a) subangular blocky
b) prismatic
c) platy
d) granular
2. The soil structure peds that are depicted
in # 2 are called __?__. 
a) massive
b) platy
c) granular
d) subangular blocky
3. The soil structure that has not yet formed distinct peds and is frequently found in the C horizon of soils developing from glacial till (clay loam soil parent material ) is called _?_.
a) subangular blocky
b) single grain
c) massive
d) columnar
4. Subsurface horizons have _____?_____ as the main ped cementing material, while in surface horizons the main cementing agent for the structural peds is __?__.
a) microbial gums.......iron oxide and clay
b) iron oxide ........hydrogen bonding
c) earthworm casts.......silt coatings
d) clay films and iron oxides.......microbial gums
5. Prairie soils will have a different sequence of horizons when compared to forest soils because of the __?__ and the horizons for a prairie soil are ___,___,____,____.
a) accumulation of leaves into a duff layer..............Oi1, Oi2, Oi3, C.
b) accumulation of leaves on the surface and extensive root system deep into the soil......A1, A2, A3, C....
c) increase in water reaching a prairie since the forest intercepts most of the precipitation.........A, Bw, C
d) acid forest floor from the yearly leave deposition and the lack of yearly leaf accumulation in a prairie......Oi, A, Bt, C ..... .
6. The pages in the Munsell soil color book have color chips that we try to match to the soil to determine the soil's color. The color chips are arranged on the page from high ____or_____ colors at the top of the page to low _____ or ______colors at the bottom of the page.
a) chroma or dark......chroma or light
b) hue or dark..... hue or light
c) value or dark..... value or light
d) value .. light......value or dark
7. The soil ped pictured below has developed from Des Moines Lobe till and is a B horizon. The B horizon will have a color that is of medium strength (or purity) and medium darkness. The slightly darker region on this ped (yellow arrow) will most likely be the Munsell color of __?__
a) 10yr 3/3
b) 5yr 4/8
c) 2.5y 2/0
d) 10yr 4/4
8. When clay accumulates in a soil the designation used for a subscript is___ , while______ is used when iron accumulates and _____ is used for zones of the soil that show only slight alterations from the parent material of color or structure.
a) t, s, w
b) c, i, k
c) t, k, w
d) w , s, t
9. Match the correct horizon designations for
this soil.
Horizon 1=(2 in.) of ls texture______
Horizon 2=(8 in.)of sand texture_____
Horizon 3=(16 in.) of sand texture_____
Horizon 4=(30 in.) of sand texture______
a)=Oi, E, Bk, C
b)=A, E, Bs, C
c)=Ap, E, Bt, C
d)=A1,A2, Bs, C
10. The soil in question 9, most likely has a moist color of __?__ in horizon 2.
a) 7.5yr 4/4
b) 10yr 6/2
c) 2.5y 4/6
d) 10yr 2/1
11. A soil with thick , dark, surface horizons that is in a depression on the landscape with only a few trees present will have horizon designations of __-__-__-__-__. _____ .
a) Ap-BA-Bw-C
b) A1-A2- AB- Bg-Cg.
c) A-E-E/B -Bt-C
d) A-Bt1-Bt2-Bt3-BC
12. When hard rock (or unweathered rock) is encountered in a soil profile, the horizon designation ______ is used.
a) R
b) RC
c) Cr
d) CR
13. Soils with a Bk horizon will have ___?___.
a) lower water transmission and more clay that horizons above and below.
b) accumulations of calcium carbonate that can be verified with HCl additions.
c) periods of saturation due to a high water table and have undergone reduction of iron.
d) more eluviation of materials out of this horizon than adjacent horizons
14. The drawn soil profile below depicts a surface horizon, subsoil and parent material with four horizons. The soil color is 10yr 2/1 for horizon 1 and 10yr 4/4 for horizon 2. The percent clay for each horizon is 24-23-24-22. The horizon designations for each layer would be __,__,__,__
a) A, Bw, BC, C.
b) A1, A2, Bw, BC.
c) Ap, E, Bt,BC
d) Oi, A, Bw, C
15. Soil Structure. Indicate the most likely soil structure for horizons: 1,2,4.----structure for horizon 1=______structure for horizon 2=_____structure for horizon 4=______.
a) granular........ subangular blocky.......massive
b) platy.........angular blocky.........massive
c) granular..........platy............structureless single grained
d) subangular blocky..........prismatic....... massive
