Soil Formation and Components Basic Soil Science AFNR-BAS-6: Describe soil formation and management and assess its relevance to plant/animal production and natural resources management.

Soil Formation formed from parent material Rocks: weathered or eroded into small particles like sand and silt weathering: wear away or change the appearance or texture of something by long exposure Organic Matter: small creatures and plants die over time in layers forming clay soils www.OneLessThing.net

Major Factors that Control the Type of Soil that Forms Climate Organisms (plant or animal) Landscape Parent Material Time www.OneLessThing.net

Soil Components Minerals made up of rocks and minerals of various sizes (sand, silt, and clay) provides texture to soils about 45% of an ideal soil www.OneLessThing.net

Soil Components Organic Matter plant, animal, or microbes that may be new to the soil or fully decomposed stabilizes the soil, aids in plant growth, stores/supplies nutrients, limits soil compaction, holds carbon, and limits the impact of pollution 5% of ideal soil www.OneLessThing.net

Soil Components Water fills spaces around soil particles (called pores or pore spaces) available for absorption by plants 25% of ideal soil www.OneLessThing.net

Soil Components Air spaces between particles allows gases, water, and organisms to travel and transfer through the soil 25% of ideal soil www.OneLessThing.net

Soil Components www.OneLessThing.net

Soil Particles Soil is made of three major components (a.k.a. soil particles) sand: the largest particle silt: the intermediate-sized particle clay: the smallest particle soil texture is determined by the percentage of each particle type (for example: sandy clay, clay sand, silty clay...) www.OneLessThing.net

Layers of Soil soil horizons: layers of soil differ in a number of easily seen soil properties such as color, texture, structure, and thickness soil profile: the arrangement of the soil horizons www.OneLessThing.net

Soil Horizons R Horizon: solid rock also known as “bedrock” lowest layer www.OneLessThing.net

Soil Horizons C Horizon: weathered parent material and broken rock very few (if any) roots found here www.OneLessThing.net

Soil Horizons B Horizon: accumulation of leached materials some tree roots are found in this layer lighter in color than the A horizon and very dense also known as “subsoil” leaching: the loss of nutrients and materials that have been dissolved as they move through soil www.OneLessThing.net

Soil Horizons A Horizon: rich in nutrients and minerals most roots are found here usually dark in color also known as “topsoil” www.OneLessThing.net

Soil Horizons O Horizon: contains organic material in the form of fresh and more decomposed plants and animals as well as microbes very top layer usually thin also known as “humus” www.OneLessThing.net

Soil Ecosystems are Important a scoop of soil can contain thousands of organisms that help determine the quality of the soil and ultimately, plant health contains earthworms, insects, burrowing animals, and microorganisms these components, along with the non-living matter in the soil, break down organic matter, recycle nutrients, and help plants grow provide physical support to anchor plants in the ground and help support the base of the plant so it can grow upward holds water like a sponge and releases that water as plants and animals need it Water is filtered as it travels through the soil removes toxins and foreign matter www.OneLessThing.net

THANK YOU FOR LEARNING WITH ONE LESS THING. “We make teaching Ag easier.” THANK YOU FOR LEARNING WITH ONE LESS THING.