Mind-builder # 6. What is the difference between soil and dirt? Dirt is just broken down rock, soil contains other sediment including organic material. ASK Yourself……. What is the end result of weathering? Or What is it that is created by the breakdown of rocks and minerals? **SOIL**.
Dirt is just broken down rock, soil contains other sediment including organic material.
~Texture or size of particle
~Structure or arrangement of particle
~Fertility or ability to hold and supply nutrients
Most soils are made up of a combination of the three basic soils: sand, silt, and clay.
Loam is soil composed of sand, silt, clay, and organic matter in evenly mixed particles of various sizes.
Sand – largest sized particles
Silt – medium sized particles
Clay – smallest size particles
Particle size can affect water and air movement through soil. If there is too much movement nutrients used for plant growth can wash away.
No movement can cause an oversaturation of water in the soil.
Types of Soil
Many different types
Each has a unique characteristics such as color, texture, structure and mineral content.
Depth of soil also varies
Kind of soil determines what type of plants can grow.
O Horizon (HUMUS)
top, organic layer of soil, made up mostly of leaf litter and humus (decomposed organic matter).
A Horizon (TOPSOIL)
Seeds germinate and plant roots grow in this dark-colored layer. It is made up of humus mixed with mineral particles.
light in color; It is made up mostly of sand and silt, having lost most of it minerals and clay as water drips through the soil. Experiences intense leaching.
B Horizon (SUBSOIL)
It contains clay and mineral deposits (like iron, aluminum oxides, and calcium carbonate) that it receives from layers above it when mineralized water drips from the soil above.
It consists of slightly broken-up bedrock. Plant roots do not penetrate into this layer; very little organic material is found in this layer.
R Horizon (BEDROCK)
The solid unweatheredrock layer that is beneath all the other layers.