1. Soil review Complexity of soils Intensity and capacity concepts
Weathering
Florida soils
Collected from over a dozen books

2. Fig. 2.1 Equilibrium redox relationships of aqueous systems.
The inscribed area is representative of most soils
pH 5
CrVI
CrIII
MnIII
MnII
FeIII
FeII
CuII
CuI
HgII
HgI
MnIV
pH 8
Pe = 16.9 E
In soils, Cr occurs predominately in the +3 and +6 oxidation states.
HW: figure out the dominant redox species of these elements in typical soils.
Kinetics, intensity and capacity
pH: 4 to 9
pe: -4 to 12
Eh: -0.3 to 0.7 v
Lindsay (1979)

4. Soil review Complexity of soils Intensity and capacity concepts
Weathering
Florida soils
Collected from over a dozen books

5. (K,Na)AlSi3O8 Al2Si2O5(OH)4 Al(OH)3/Fe2O3 (K,Ca)0.16Al(Si2O5)OH 2:1
1:1
0:1
Layer silicate
Dominant minerals in Florida
Fergusson, 1989
JCB lecture

6. Kabata-Pendias and Pendias (1992)
Why large surface areas for layer silicates
1 cmol= 10 m eq.
What minrals do you see in Florida? Why a range?
Kabata-Pendias and Pendias (1992)

7. Permanent and pH-dependent PZC Mn oxides (1.2-4.0) Fe oxide (8)
CEC: permanent and Ph-dependent
Why MnO is not affected by pH? Where Kaolinite will fit?
Point of zero charge
Adriano (2001)

8. Soil review Complexity of soils Intensity and capacity concepts
Weathering
Florida soils
Collected from over a dozen books

9. Major Florida soil types
Ultisols
Spodosols
Entisols
Histosols
7 out of 12 orders, 4 major in Florida
1 organic and 11 mineral soils
Histosols: muck or peat, accumulation of OC in wet environment
Ultisols: high in clay, has a clay layer in subsurface
Major Florida soil types

10. Properties of Florida surface soils
CEC
Clay
Silt
Sand OC pH
Soil
Cmol kg-1 %
Entisols (no coating)
1.59
0.40
0.50
99.0
0.41
5.30
Entisols (s coating)
4.79
1.80
1.30
97.0
0.77
5.03
Entisols (coating)
4.98
2.10
4.00
94.0
0.98
5.36
Spodosols
12.2
1.29
3.93
94.8
2.30
4.54
Ultisols
7.41
3.80
6.92
89.3
1.11
5.05
Weathering, losing Na, K, Ca and Mg hard Lewis bases
Ma, L.Q., F. Tan and W.G. Harris.  1997.  Concentrations and distributions of 11 elements in Florida soils.     J. Environ. Qual.  26:

11. D. Hardison

12. Kabata-Pendias and Pendias (1992)
Three phases: not concrete solid
Concern: Liquid > air > solid
Solid phase: organic and inorganic
Inorganic-minerals: present as sand, silt and clay
Organic: Living phase.
Heavier than water?
Soil moisture content: volume basis, what about mass basis
Density of minerals.
Kabata-Pendias and Pendias (1992)