SOIL AS AN ECOSYSTEM INTRODUCTION TO SOILS FIELD STUDY What do we know about soil now? What makes up soil? What lives there? Where does soil come from? How does soil contribute to the ecological community of place?

Why should we care?  Soil hold nutrients for our plants to grow  The nutrients come from decaying organic material, a process known as decomposition  Soil holds rainwater, which is made available during dry periods  Keeps stream flowing year round!  Acts as filter and removes impurities

Why should we care?  Provides support for human built structures  Provides support for the roots of plants and trees  Soil is an ecosystem, supporting many forms of life  Single celled bacteria  Worms  Fungi

SOIL AS AN ECOSYSTEM INTRODUCTION TO SOILS FIELD STUDY Some terms we should learn to talk about soils:

SOIL AS AN ECOSYSTEM INTRODUCTION TO SOILS FIELD STUDY Some terms we should learn to talk about soils: Definition: Ecosystem: An interacting natural environment including all of its living and non-living parts.

SOIL AS AN ECOSYSTEM INTRODUCTION TO SOILS FIELD STUDY Some terms we should learn to talk about soils: Definition: Organic: Materials that contain carbon compounds. Most living things contain carbon compounds.

SOIL AS AN ECOSYSTEM INTRODUCTION TO SOILS FIELD STUDY Some terms we should learn to talk about soils: Definition: Organic: Materials that contain carbon compounds. Most living things contain carbon compounds. Definition: Inorganic: Materials such as minerals that are not products of organic life.

Organic Materials…  Living Plants  Living Animals  Dead, decomposing plants  Dead, decomposing animals

Inorganic Materials…  Particles of rocks of various sizes  What is another name for the inorganic material in soil? Minerals

SOIL AS AN ECOSYSTEM INTRODUCTION TO SOILS FIELD STUDY Parts of a Soil Ecosystem:

SOIL AS AN ECOSYSTEM INTRODUCTION TO SOILS FIELD STUDY Soil Air: Pore spaces for the exchange of gases. Soil Water: Stored in the soil for plant use. Contains important nutrients for plant growth. Soil Organic Matter: Organic materials and biological life that is incorporated into the soil. Soil Minerals: rocks and soil particles that make up soil solids.

SOIL AS AN ECOSYSTEM INTRODUCTION TO SOILS FIELD STUDY Soil Air: About 25% Soil Water: About 25% Soil Organic Matter: About 6% Soil Minerals: About 44%

SOIL AS AN ECOSYSTEM INTRODUCTION TO SOILS FIELD STUDY Soil Air: About 25% Soil Water: About 25% Soil Organic Mater: About 6% Soil Minerals: About 44%

Soil Characteristics  Color  Structure  Texture  Depth  Nutrient Content

HOW SOIL FORMS INTRODUCTION TO SOILS FIELD STUDY 5 Factors in the landscape combine to make the soil we find in a place and define the characteristics that soil will have.

HOW SOIL FORMS INTRODUCTION TO SOILS FIELD STUDY Factor 1: Topography Definition: The slope of the land which can be one of the things that determines the type of soil that is formed. Soils are typically less nutritious on steep slopes, because there is more opportunity for erosion and weathering. Soil is deeper and richer in valleys and flat areas.

HOW SOIL FORMS INTRODUCTION TO SOILS FIELD STUDY Factor 2: Climate Definition: The average weather patterns for a region that occur over a number of years. Includes temperature, precipitation, and wind Climate can inhibit soil formation through wind and weather erosion. Moist climates promote soil development by allowing for rapid decomposition of organic matter

HOW SOIL FORMS INTRODUCTION TO SOILS FIELD STUDY Factor 3: Parent Material Definition: Any material from which soil is formed. Includes: Inorganic material, like weathered bedrock or materials deposited by water

HOW SOIL FORMS INTRODUCTION TO SOILS FIELD STUDY Factor 4: Biologic Influences Definition: Living organisms that influence the development of the soil and soil profile. Plant and animal life eventually become the organic material Deserts do not have much plant and animal life, so there is not much organic matter in that soil.

HOW SOIL FORMS INTRODUCTION TO SOILS FIELD STUDY Factor 5: Time Definition: The amount of time the soil has been forming. Inorganic materials depend on the rocks and minerals present in the area Rocks break down by a process known as weathering

THE SOIL PROFILE INTRODUCTION TO SOILS FIELD STUDY The 5 Soil Forming Factors combine to make the soil below us. Every place is a little different, depending on the specifics of how the 5 soil forming factors have combined at that specific place.

THE SOIL PROFILE INTRODUCTION TO SOILS FIELD STUDY As soils continue to form they can develop several distinctive layers from the top (surface of the ground) down into the Earth. When we look at the soil as a vertical column we call is a “Soil Profile.”

LAYERS OF A SOIL PROFILE INTRODUCTION TO SOILS FIELD STUDY Duff: Duff is made up of leaf litter and other organic materials lying on the surface of the soil (not always present in a profile).

LAYERS OF A SOIL PROFILE INTRODUCTION TO SOILS FIELD STUDY Topsoil: The fertile layer of soil below the duff layer, and above the subsoil. The fertile layer that has organic matter incorporated within it and contains many nutrients.

LAYERS OF A SOIL PROFILE INTRODUCTION TO SOILS FIELD STUDY Subsoil: The layer of soil in a soil profile that is below the topsoil.

LAYERS OF A SOIL PROFILE INTRODUCTION TO SOILS FIELD STUDY Bedrock: A solid layer of rock beneath some soils (not shown in this picture).