Diagnostic horizon and designation

Question 1

Mollic - surface horizon

Answer 1

(A) Thick, dark colored, high base saturation, strong structure

Question 2

Umbric - surface horizon

Answer 2

(A) Same as except low base satruation

Question 3

Ochric - surface horizon

Answer 3

(A) Light colored, low organic content, may be hard and massive when dry

Question 4

Melanic - surface horizon

Answer 4

(A) Thick, black, high in organic matter (>6% organic C) common in volcanic ash soils

Question 5

Histic - surface horizon

Answer 5

(O) Very high in organic content, wet during some part of year

Question 6

Anthropic - surface horizon

Answer 6

(A) Human-modified mollic-like horizon, high in available P

Question 7

Plaggan - surface horizon

Answer 7

(A) Human-made sodlike horizon created by years of manuring

Question 8

Argillic - subsurface horizon

Answer 8

(Bt) Silicate clay accumulation

Question 9

Natric - subsurface horizon

Answer 9

(Btn) Argillic, high in sodium, columnar or prismatic structure

Question 10

Spodic - subsurface horizon

Answer 10

(Bhs) Organic matter, Fe and Al oxides accumulation

Question 11

Cambic - subsurface horizon

Answer 11

(B) Changed or altered by physical movement or by chemical reaction

Question 12

Agric - subsurface horizon

Answer 12

(A or B) Organic and clay accumulation just below plow layer resulting from cultivation

Question 13

Oxic - subsurface horizon

Answer 13

(Bo) Highly weathered, primarily mixture of Fe, Al oxides and non-sticky-type silicate clays

Question 14

Duripan - subsurface horizon

Answer 14

(m) Hardpan, strong cemented by silica

Question 15

Fragipan - subsurface horizon

Answer 15

(x) Brittle pan, usually loamy textured, weakly cemented

Question 16

Albic - subsurface horizon

Answer 16

(E) Light colored, clay and Fe and Al oxides mostly removed

Question 17

Calcic - subsurface horizon

Answer 17

(k) Accumulation of CaCO3 or CaCO3 - MgCO3

Question 18

Gypsic - subsurface horizon

Answer 18

(y) Accumulation of gypsum

Question 19

Salic - subsurface horizon

Answer 19

(z) Accumulation of salts

Question 20

Kandic - subsurface horizon

Answer 20

Accumulation of low-activity clays

Question 21

Petrocalcic - subsurface horizon

Answer 21

Cemented calcic horizon

Question 22

Petrogypsic - subsurface horizon

Answer 22

cemented gypsic horizon

Question 23

Placic - subsurface horizon

Answer 23

Thin pan cemented with iron alone or with manganese or organic matter

Question 24

Sombric - subsurface horizon

Answer 24

Organic matter accumulation

Question 25

Sulfuric - subsurface horizon

Answer 25

Highly acid with Jarosite mottles