Transcript Soil - Parrott

Soil

Soil is made through the weathering of
rocks, combined with living organisms, &
decaying organic material
Scientists
think it
takes 200300 years
for 1 cm of
soil to form!
What sediments make up Soil?
Sand – good drainage and aeration
 Silt – good for plant growth
 Clay – holds water well, doesn’t drain well.

Texture

Loam is best
because it has equal
distribution of all 3
sediments
Let’a try a few together on the
handout:
1. 40% sand
50% silt
10% clay
2. 30% sand
40% silt
30% clay
What soil type(s) do we
have in Mecklenburg
County?
How are soils formed?




Climate - provides sources of erosion
Relief or topography - affects the retention of soil
Organisms: - breaks down to provide nutrients
Parent Material - must have starting bedrock
material to break down
 Time - nutrients accumulate until they are at a
stable place
BrainPop on Soil
Porosity
Soil Layers

R Horizon
 Bedrock (parent
material)
 In Piedmont of NC,
this is Igneous and
Metamorphic rocks

For our model, let’s
start with a bedrock of
marshmallow igneous
rocks!
Soil Layers

Aquifer
 This is where our
groundwater is

For our model, let’s
use pudding to
replicate our aquifer!
High
porosity
Soil Layers

C Horizon
 Broken down parts of
bedrock; no roots or
organic material

For our model, let’s
use Hershey’s kisses
to simulate regolith!
Soil Layers

B Horizon
 AKA subsoil; little
organic matter, mostly
clay from above layers

For our model, let’s
use big pieces of Oreo
cookie to represent the
subsoil!
Soil Layers

E Horizon
 Mostly sand and silt;
most of clay has
leached down to B
horizon

For our model, let’s
use vanilla wafer
crumbs to represent
the subsoil!
Soil Layers

A Horizon
 Dark colored and
most fertile; lots
of organic matter

For our model,
let’s use graham
cracker crumbs to
represent topsoil!
Soil Layers

O Horizon
 Where most
organisms (plants
and animals) exist

For our model,
let’s use gummy
worms to represent
decomposers!