How Soil Forms

            Students investigate and compare the proportions and feel of two different soils. ·       

Soil A is made up of 5/8 sand grains, 1/8 clay grains, and 2/8 humus.

Soil B is made up of 1/8 sand grains, 4/8 clay grains, and 3/8 humus.

Which of these is true?

• Soil B would feel rougher than Soil A.

• Soil A would feel smoother than Soil B.

• Soil A would have more visible particles than Soil B.

• Soil B would have more visible particles than Soil A.

Layla wants to explore how soils are formed.

She observes the picture shown.

Which explains how the tree helps form soil?

• Roots under the tree hold the tree in the ground.

• Branches from the tree reach up toward sunlight.

• The plants under the tree do not get as much sunlight.

• Dead leaves fall and result in decomposition of plant remains.

Neva was asked by her teacher to investigate the steps in soil formation.

How is soil formed?

Drag the step to the correct picture to show the order of the steps for how soil forms.

• Step 2

• 
• Step 3

• 
• Step 1

• 

Tags

NGSS.MS-ESS2-2

NGSS.MS-ESS2-1

NGSS.MS-ESS2-4

Sandy soil and clay soil under a microscope are shown. ​ Both types of soil are made of ​ ​ (a)  

• weathered rock.
• plants.
• smaller.

Sandy soil and clay soil under a microscope are shown. The particles in the clay soil are ​ (a)   than the particles in the sandy soil.

• smaller
• larger
• the same

Sandy soil and clay soil under a microscope are shown. These two soils will have ​ (a)   properties.

• different
• the same

Tags

NGSS.MS-ESS2-2

Label the two types of soil.

a

b

Clay soil

Sandy soil

The process of weathering shown in the pictures below is in the wrong order. Number the pictures in the correct order (1, 2, 3, 4) to show how weathering helps rock become part of the soil.

a

b

c

d

1

3

2

4

Tags

NGSS.MS-ESS2-2

Match the following vocabulary words to their definitions.

• the breaking down of rocks

• soil

• pieces of rock and once-living things

• humus

• soil made of once-living things

• weathering

Draw sandy soil and clay soil.