Soil Profile Description
SOIL PROFILE DESCRIPTION
Soil – 206 Soil Ecosystem Lab
Objectives
After completion of this lab a student should be able to:
1. Define the terms soil profile, horizon, texture, structure and concentration.
2. Describe how textural class is determined using the feel method.
3. Understand how to use the soil textural triangle.
4. Identify and describe four structure types and indicate their probable location in a soil profile.
5. List 5 soil colors and give a possible cause for each color.
Introduction
The word soil, in a general sense refers to all of the unconsolidated material occupying the earth’s surface. Soil is a mixture of varying proportions of inorganic mineral and rock particles, living and organic matter, and voids or pores which contain variable amounts of air and water. It develops at the interface between the atmosphere and lithosphere (bedrock), forming a blanket ranging in thickness from a few centimeters to two meters or more.
Soil is the medium from which most plants derive mineral nutrients and water. Soil also provides physical support for both plants and animals including humans and the structures they build. As you proceed through these lab exercises, keep in mind that a soil is not an inert, unchanging material. Rather, at any one time, a soil may be undergoing many simultaneous physical, chemical, and biological changes.
A distinction may be made between the soil (in the general sense) and an individual soil body. An individual soil body, called a polypedon by soil scientists, is a three dimensional body with definite recognizable boundaries. Its upper boundary is the earth’s surface, and its lower boundary is the lower limit of biological activity and weathering. A polypedon is bounded laterally by other soils with properties different from those of the polypedon being considered. Thus, the general term “soil” is actually a collective term for a large number of individual soils, each having its own distinguishing characteristics.
Refer to
Soil – 206 Soil Ecosystem Lab
Objectives
After completion of this lab a student should be able to:
1. Define the terms soil profile, horizon, texture, structure and concentration.
2. Describe how textural class is determined using the feel method.
3. Understand how to use the soil textural triangle.
4. Identify and describe four structure types and indicate their probable location in a soil profile.
5. List 5 soil colors and give a possible cause for each color.
Introduction
The word soil, in a general sense refers to all of the unconsolidated material occupying the earth’s surface. Soil is a mixture of varying proportions of inorganic mineral and rock particles, living and organic matter, and voids or pores which contain variable amounts of air and water. It develops at the interface between the atmosphere and lithosphere (bedrock), forming a blanket ranging in thickness from a few centimeters to two meters or more.
Soil is the medium from which most plants derive mineral nutrients and water. Soil also provides physical support for both plants and animals including humans and the structures they build. As you proceed through these lab exercises, keep in mind that a soil is not an inert, unchanging material. Rather, at any one time, a soil may be undergoing many simultaneous physical, chemical, and biological changes.
A distinction may be made between the soil (in the general sense) and an individual soil body. An individual soil body, called a polypedon by soil scientists, is a three dimensional body with definite recognizable boundaries. Its upper boundary is the earth’s surface, and its lower boundary is the lower limit of biological activity and weathering. A polypedon is bounded laterally by other soils with properties different from those of the polypedon being considered. Thus, the general term “soil” is actually a collective term for a large number of individual soils, each having its own distinguishing characteristics.
Refer to