 Material that supports plant life
 O= Organic layer= humus
 A= Topsoil, mixture of
organic & minerals
 E= Eluvial (leached) mineral horizon
 B= Subsoil: accumulation of organic
&/or inorganic matter
 C = Parent material, un-weathered
 Climate
 Topography(relief)
 Time
 Organisms
 Parent material
 Gravitational water: water that moves through soil
under the influence of gravity.
 Field capacity: water held in the soil by capillary
forces, available to plant
 Hygroscopic water: water that is adsorbed by soil
particles, unavailable to plant
 Adsorbed: held in place, attached to

Inorganic: Synthesized from
minerals
Organic: from plant and
animals
 Quick release
 Slow release
 Short term plant growth
 Long term soil health
Excess nutrients :
Human harm: methemoglobinemia (Blue Baby Syndrome)
Environmental harm: eutrophication
3 cm
1 cm
 Smaller particles have a
54cm2
162cm2
 Higher chemical reactivity: clay is (-) attracts (+)
 Greater surface area:
 Nutrients: Mg+, Ca+, K+, Na+
 Non-nutrients : H+
 Higher water holding capacity: water is polar
 Is it 33% for all separates?
 What soil type is
 18% clay, 40% sand, 42% silt?
 This point is where each separate
has equal influence
 How much sand is required to get
its name in a class?
 Last word is most important
 Does more clay mean Gravitational water: water that moves through soil
more available water? under the influence of gravity.
 Plants can survive withField capacity: water held in the soil by capillary forces
50% of FC.
Hygroscopic water: water that is adsorbed by soil
particles
 Intensive monoculture farming
 Row crops, altering the landscape, weed free
 Physical damage:
 Erosion
 Compaction: reduce aeration
 Chemical damage
 Salinization
 Conversion
 Desertification
Drummer
Silty, clay
loam
Casa
Grande
Sandy Loam
Houston Black
Black clay
Myakka
Fine sand
Drummer
Silty, clay
loam
Casa
Grande
Sandy Loam
Houston Black
Black clay
Myakka
Fine sand
 What soil type would most likely need to have more






fertilizer applied to it?
Which farmer will need to irrigate their crops most often?
Which farmer will most likely have to face salinization
problems?
Which farmer would most likely encounter gully or sheet
erosion?
Which farmer would most likely have waterlogged soil if
there was a heavy rainfall?
Which farmer has the best developed “O” horizon?
Which farmer would most likely have the most acidic soil?