Agriculture Reference
In-Depth Information
Table 19.5
Simplified Key to the WRB Reference Soil Groups
1
Organic materials
> 40 cm deep
yes
11
Plinthite or petroplinthite
within 50 cm
yes
21
Argic horizon and
albeluvic tonguing
yes
HISTOSOLS
PLINTHOSOLS
ALBELUVISOLS
→
→
→
↓
no
↓
no
↓
no
2
ryic horizon
yes
12
Ferralic horizon
yes
22
Argic horizon with
CEC
yes
→
CRYOSOLS
→
FERRALSOLS
> 24, Al
> 60%
→
ALISOLS
c
sat
no
no
no
↓
↓
↓
3
Human
modifications
yes
13
Natric horizon
yes
23
Argic and nitic horizons
yes
ANTHROSOLS
SOLONETZ
NITISOLS
→
→
→
↓
no
↓
no
↓
no
4
Depth < 25 cm
yes
14
Abrupt textural change
yes
24
Argic horizon with
CEC
yes
→
LEPTOSOLS
→
PLANOSOLS
< 24, BS < 50%
→
ACRISOLS
c
no
no
no
↓
↓
↓
5
> 35% swell-clay
vertic horizon
yes
15
Chernic or dark
mollic horizon
yes
25
Argic horizon with
CEC
yes
VERTISOLS
CHERNOZEMS
> 24
LUVISOLS
→
→
→
c
↓
no
↓
no
↓
no
6
Fluvic materials
yes
16
Brownish mollic horizon
and secondary CaCO
yes
26
Argic horizon with
CEC
yes
→
FLUVISOLS
→
KASTANOZEMS
< 24, BS > 50%
→
LIXISOLS
3
c
no
no
no
↓
↓
↓
7
Salic horizon
yes
17
Mollic horizon
yes
27
Umbric horizon
yes
SOLONCHAKS
PHAEOZEMS
UMBRISOLS
→
→
→
↓
no
↓
no
↓
no
8
Gleyic properties
yes
18
Gypsic or petrogypsic
horizon
yes
28
Cambic horizon
yes
→
GLEYSOLS
→
GYPSISOLS
→
CAMBISOLS
no
no
no
↓
↓
↓
9
Andic or vitric
horizon
yes
19
Duric or petroduric
horizon
yes
29
Coarse texture > 100 cm
yes
ANDOSOLS
DURISOLS
ARENOSOLS
→
→
→
↓
no
↓
no
↓
no
10
Spodic horizon
yes
20
Calcic or petrocalcic
horizon
yes
30
Other soils
REGOSOLS
→
→
PODZOLS
→
CALCISOLS
no
no
↓
↓
Adapted from ISSS/ISRIC/FAO, 1998b.
