Second Grade Garden - Lesson 2 Soil

We are starting the year by looking at how plants grow and spread.  The first piece to this puzzle is the soil.

Lesson Goals:

• Understand that different soils hold water differently.
• Understand that different soils offer different amounts of resistance to root growth.
• Know that the most desired type of soil is “Loam” although different plants have different needs.

Overview:

• Three main types of soil (we looked at examples of each)
• Sand (brought in sand from the sandbox)
• Clay (just brought in some dirt from the backyard - we have soil with a lot of clay in it)
• Silt (no example of this one)
• Discussed particle size
• Sand is made up of the largest particles
• Silt has the next largest
• Clay has the smallest particles
• Discussed how particle size affects the ability of the soil to hold water and to hold plants
• Sand - cannot easily hold plants; water filters through it quickly
• Silt - has smaller particles than sand so its better at holding water and plants
• Clay has the smallest particles so its very compact and can hold the roots of plants very well but it offers a lot of resistance to root growth; it also holds a lot of water in the soil and doesn't filter it through
• The most desired type of soil is loam.  Loam is "a type of soil that is good for growing plants".  Loam is good for vegetable gardens...but not cacti. 
• Soil can be amended to create loam.  Compost or sand or clay can be added to soil to create loam.

Table 1

Materials needed:

• cups with hole in bottom
• sand samples
• clay soil samples
• water
• cups for catching water 

Put some sand in one cup with a hole in it and clay soil in the other cup with a hole in it.
Pour some water into each cup and observe how quickly water comes out the hole and how much water comes out.  Water should come out of the sand cup faster and more sand should come out of the sand sample cup.

An expanded version of this experiment can be found at https://utah.agclassroom.org/teachercenter/index.cfm?controller=main&action=lpsearch&lpID=499&searchGrade.gradeID=5&searchSub.subjectID=2

Table 2

Materials needed:

• worksheet
• pencils

Introduce the graph and show how to read it.  Each of the examples are native Californian plants.

Worksheet (click here for document)



Garden

We walked around the garden and looked at the soil.  We discussed why what we planted has not come up yet.  The kids shared their observations.


Enjoy!