SOIL. Soil: is a mixture of weathered rock particles and other materials.
Chapter 3 Lesson 3 Essential Question: What is soil made up of? TYPES OF SOIL & PARTICLES.
-
Upload
laurence-bruce -
Category
Documents
-
view
229 -
download
3
Transcript of Chapter 3 Lesson 3 Essential Question: What is soil made up of? TYPES OF SOIL & PARTICLES.
Chapter 3 Lesson 3
Essential Question: What is soil made up of?
TYPES OF SOIL & PARTICLES
Lesson 3 Vocabulary•soil•topsoil•subsoil•contour plowing•terrace farming
Observations
Facts
Silt
Sand
Loam
Clay
What is soil made up of?
• moderate size• smooth floury
texture
• largest particle• gritty feel
• smallest particle
• feels sticky
combination of sand, silt, and clay
Sizes of Soil Particles
smallest to largest:claysiltfine sandmedium sandcoarse sand
Try This!Identifying Soil Texture
1. Spread soil on newspaper. Remove all rocks, trash, roots, etc. Crush all lumps.
2. Fill a tall, slender jar ¼ full of soil.3. Add water until the jar is ¾ full.4. Add a teaspoon of non-foaming dishwasher
detergent.5. Put on a tight fitting lid and shake hard for 10-15
minutes. This shaking breaks apart the soil aggregates and separates the soil into individual mineral particles.
6. Set the jar where it will not be disturbed for 2-3 days.7. Soil particles will settle out according to size.8. After 1 minute, mark on the jar the depth of the
sand.9. After 2 hours, mark the depth of silt.10.When the water clears (1-3 days or more), mark
the clay levels.11.Measure the thickness of sand, silt, and clay layers
and calculate the percentages of each.12.Refer to the soil texture triangle and identify your
soil.
Soil Texture Experiment
Measure the thickness of the sand, silt, and clay.
thickness of sand = ______ inches
thickness of silt = _______ inches
thickness of clay = _______ inches
TOTAL = _______ inches
Calculate the percentage of sand, silt, and clay.
sand thickness / total thickness = ______ percent sand
silt thickness / total thickness = ______ percent silt
clay thickness / total thickness = ______ percent clayIdentify soil texture using the soil
texture triangle.
Soil Texture Triangle
For example, a soil with 30% clay, 50% sand, 20%silt is called a sandy loam.
A natural resource made up of minerals and small rocks, gases, water, and organic matter = soil
topsoil
subsoil
bedrock
Georgia’s soil
• looks red because it contains lots of iron• Cotton
grows well in our soil.
Flashback to the 1930’s:Drought caused big problems for farmers. Without rain, land was extra dry. Because
farmers planted their crops in long, straight lines, the wind blew through their fields more strongly and blew their topsoil away. Crops
could not grow!
Protecting TopsoilContour plowing: soil is plowed in curved rows that follow the shape of the land. This decreases wind and water damage to the land.
Farmers keep soil in place by planting cover crops. This is what happens: Soil sticks to plant roots. Stems & leaves protect the soil from wind.
Farmers protect soil that is lost from moving down hills by using terrace farming. Crops are planted on level sections.