Soil is the growing medium for our food
Without it we could not survive
Soil purifies our waste
Soil is home to plants and animals
It may take up to 100 years to form one inch of topsoil
We are losing so much soil to erosion each year that the lost
soil if loaded into dump trucks parked back to back would
extend to the moon and back.
An earthworm can work a ton of soil a year
•Soil is made up of
mineral grains.
•Water is held between
the grains in the pore
spaces.
•25% of the soil is air.
Oxygen is essential
•Organic matter is
both coarse and fine.
•Bacteria- A thimble of
soil can contain 2
billion bacteria, 30
million fungi
fragments and 100,000
single cell plants and
animals.
Animals making burrows in the soil help bring air and water into the
soil
Generally, Inner Coastal Plain soils are fertile(they can
support hearty natural growth of a wide variety of plants)
The upper layers of the Inner Coastal Plain soils are
brownish and remain moist between rains
Outer Coastal Plain soils are very sandy, infertile, and
chemically acidic.
OCP soils capture water well, but it quickly percolates into
the lower layers.
OCP soils have a light color
Blueberries and cranberries are well suited to growing in
“infertile” soil of the OCP.
Humus
gives the
topsoil a
rich brown
color
Leaching
takes
minerals
carried by
water to
the
subsoil
D
In a mature soil profile,
there are three distinct
layers(horizons) of the
soil. The undisturbed rock
below the soil is called the
bedrock.
The Ao-horizon consists
of the highly decayed
organic material referred
to as the peat and humus.
Humus gives soil horizon
A a rich brown color.We
see no such brown layer in
the Pine Barrens.
In the A horizon,
water percolates
downward and
carries minerals as
it goes. This is
called “leaching.”
Leaching carries
minerals down
into the lower soil
horizons.
The B-Horizon is called the
subsoil.
This horizon is where the
leached minerals from
horizon A end up.
These leached minerals may
color the subsoil. For
example, the presence of iron
my color the subsoil red.
Horizon B-Zone of Accumulation of leached minerals
The C-horizon is called the
zone of weathered bedrock.
When you have a residual soil,
one formed over the original
bedrock, the C-horizon
resembles the bedrock, but it
is weathered.
In a residual soil, the bedrock
is below the C-horizon.
Remember that the Coastal
Plain does not have bedrock
under the soil profile, but it
has layers of sand, clay and
gravel. That is because of the
sea level changes over time
and the rivers that flowed over
it.
Sandy particles are the only particles
which may be large enough to be seen
with the naked eye. Predominantly
sandy soil has a gritty feel (coarsetextured) when rubbed between the
fingers.
Silt particles are smaller than sand
particles. Predominantly silty soils feel
powdery (like flour) and do not hold
together well when wet, though they
are more cohesive than sandy soils.
Loam is the best soil texture
for growing things. It is a
mixture that has useful
amounts of clay and silt in a
base of sand.
Clayey soil has the smallest soil
particles, and many small pore spaces.
Soils with a high number of clay
particles have a very high water
holding capacity and are very finetextured, making them feel smooth
and sticky (like soap) when wet.
The top sieve is gravel- set
aside
The second and third sieves
are sand
The fourth sieve is silt
The bottom pan is clay
Coarse-textured soils have a high sand content.
They consist of large particles with uneven surfaces
and because of this, have large pore spaces
These traits make such soils loose and easy to work;
however, the large spaces do not retain water or
nutrients. Water infiltrates sandy soil and percolates
(moves through it) quickly and easily. As a result,
sandy soils are generally dry and infertile.
The dryness of sandy soil contributes to a shortage of
nutrients because of less vegetative growth and,
therefore, less organic matter is produced.
Medium-textured soils known as loams, have
properties in between those of coarse and fine
texture. Silty loams to sandy-clay loams have a
good capacity to retain water without becoming
waterlogged. They are easy to work and form
good clumping mixtures during cultivation.
Loams contain a good supply of nutrients,
necessary for the organisms living in the soil.
Loam or silty soils have a texture which is most
suitable for the greatest variety of living
organisms.
Fine-textured soils range from silty clay to heavy clay.
Heavy clays are like soft plastic when wet and are hard when dry.
This makes them difficult to work.
Clays are often waterlogged and poorly aerated, as well as being
cool. Clay soils absorb and release water (to plants) very slowly.
Air movement within the soil is also very slow. These conditions
mean that clay soils take longer to warm than coarser soils.
A lot of water in the spaces can mean little air is available for
living organisms to carry out cellular respiration and certain
biochemical actions.
Fertile soil contains nutrients. There are major
nutrients and micro nutrients. Major nutrients make
up the bulk of the nutrients in your soil. The most
important major nutrients are :Nitrogen, Potassium and
Phosphorus. Other major nutrients are :Calcium,
Magnesium and Sulfur.
Micronutrients are: Manganese, Iron, Copper, Zinc, and
Boron.
Nutrients need to be balanced and available to the
plant's roots. Organic matter is key to helping
maintain this balance.
Application of lime helps to neutralize acidic soil. The
calcium and magnesium ions in lime will bump some of
the hydrogen ions off the clay particles. The hydrogen is
then leached downward by water and the soil becomes
less acidic.