Soil Much more than "dirt"

Why is soil important? 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

What makes up soil? 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. What makes up soil?

Animals making burrows in the soil help bring air and water into the soil

Inner and Outer Coastal Plain 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 Topsoil Subsoil Weathered Bedrock D Bedrock

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 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.

Soil texture refers to grain size 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 (coarse-textured) 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. 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 fine-textured, making them feel smooth and sticky (like soap) when wet. 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.

Soil Fractions

Soil texture graph

Soil Fractions The top sieve is gravel- set aside The second and third sieves are sand The fourth sieve is silt The bottom pan is clay