The Ground Beneath Our Feet S6E5h. Describe soil as consisting of weathered rocks and decomposed organic material.

What Makes Up Healthy Soil? Mineral fragments, humus, air, water, and living things such as Plant roots, Insects, Worms Humus Organic Material Forms from decayed plant and animal material Can support the growth of vegetation Parent rock The source of mineral fragments in the soil

Soil Formation Soil starts out as rock The surface rock breaks down into smaller pieces and is mixed with organic matter. Over time this creates a thin layer of soil. Decaying matter makes the soil thick and rich

Soil Formation Video http://nroc.mpls.k12.mn.us/Environmental%20Science/course%20files/multimedia/lesson17/animations/2c_soil_formation.html

Soil Particles

Different Types of Soil Every soil type is a mixture of sand, silt, clay. The right mixture is called loam. Loam = 40% sand 40 % silt 20 % clay

Soil Profile The vertical display of soil horizons. Each soil profile is different from another. http://courses.soil.ncsu.edu/resources/soil_classification_genesis/soil_formation/soil_transform.swf

What is a Soil horizon? O - Litter from dead plants & animals A Topsoil E Zone of intense leaching. B Collects dissolved substances from upper horizons (sub soil) C Weathered bedrock R Bedrock

Review Questions Which particle is the biggest one that goes in soil? A. Clay B. Silt C. Quartz D. Sand

Review Questions 2. Horizon C is made mostly of A. Humus B. Organic Material C. Bedrock D. Weathered Rock O A B C

Review Questions 3. What is loam? A. Loam is the perfect mixture of 40 % sand, 40% silt, and 20 % clay. B. Loam is the combination of 30% sand, 40% mud, and 30% clay. C. Loam is located in horizon B. D. Loam is the particle quality of any soil.

Review Questions 4. What is missing from this profile? A. Humus B. Organic Material C. Bedrock D. Weathered Rock O A B C

Review Questions 5. How does soil start? - A. A large rock is weathered - B. Bits & pieces of rocks are cemented together - C. Decaying matter is compacted together - D. None of the above

Review Questions 1. Which particle is the biggest one that goes in soil? A. Clay B. Silt C. Quartz D. Sand

Review Questions 2. Horizon C is made mostly of A. Humus B. Organic Material C. Bedrock D. Weathered Rock O A B C

Review Questions 3. What is loam? A. Loam is the perfect mixture of 40% sand, 40%silt, and 20% clay. B. Loam is the combination of 30% sand, 40% mud, and 30% clay. C. Loam is located in horizon B. D. Loam is the particle quality of any soil.

Review Questions 4. What is missing from this profile? A. Humus B. Organic Material C. Bedrock D. Weathered Rock O A B C

Review Questions 5. How does soil start? - A. A large rock is weathered - B. Bits & pieces of rocks are cemented together - C. Decaying matter is compacted together - D. None of the above