Summary

In this lab, students will learn about the draining properties of different types of soil and how it affects the type of plants that can grow in those soils.

Grade Level

Elementary School

NGSS Alignment

This lab will help prepare your students to meet the performance expectations in the following standards:

• 2-PS1-1: Plan and conduct an investigation to describe and classify different kinds of materials by their observable properties.
• 2-PS1-2: Analyze data obtained from testing different materials to determine which materials have the properties that are best suited for an intended purpose.

Objectives

By the end of this lab, students should be able to

• Understand drainage rates or permeability of soil.
• Determine what types of plants can grow in different soils based on their draining rates.

Chemistry Topics

This lab supports students’ understanding of

• Physical Properties
• Observations
• Soil properties
• Permeability
• Water
• Plant properties

Time

Teacher Preparation: 30 minutes

Lesson: 60 minutes

Materials

• Clear plastic cups or jars of the same size (number depends on group size and number of soil samples)
• Paper towels
• ¼ cup Potting soil (per group)
• ¼ cup Sand (per group)
  • From a bag or from a beach/lake/sandbox
• Two other samples of soil (¼ cup of each per group)
  • From the schoolyard, or assign students to bring in a sample from home
• Labels
• Stop watch
• Ruler (metric)
• Tap Water
• Rubber bands (one per cup/jar)
• Dry erase marker or permanent marker (to draw a mark on the cup/jar)

Safety

• Always wear safety goggles when handling chemicals in the lab.
• Students should wash their hands thoroughly before leaving the lab.
• When students complete the lab, instruct them how to clean up their materials and dispose of any chemicals.

Teacher Notes

• 3-5 students per group is suggested.
• Each student will have their own sample to watch and record and will then share results as a group
  1. Each group will have sand and potting soil as baselines, the other samples can be different among the groups if you assigned students to bring in their own soil samples.
• For timing the experiment, use stopwatches:
  1. One per student to record how fast the first water drop falls compared to the others in their group.
  2. OR you can have the students raise their hands to report when the water drops.
  3. OR students can tell their group when their water falls first.
• You can do the experiment a second time for the same soil: have the students add another 2cm of water to see what happens and have them record their observations. Before they do the experiment a second time, ask them what they think would happen the second time.
• You can use this lesson to also discuss rain and the water cycle, saturated soils, soil pollution, and flooding.
  1. This is a video from the National Resources Conservation Service (NRCS) about soil saturation, and soil in general.
  2. This is a video about the basics of soil that is good for kids to understand what soil is made up of.
  3. This is a short video about permeability and the water cycle.
• You can expand this lesson by talking about different ecosystems like deserts and rainforests and what type of plants and animals live there and how they’ve adapted to the desert climate. Suggestions for questioning: What sort of soils do the students think would be in deserts and rainforests? For older students, you can include the tundra (cold deserts, essentially) and talk about permafrost and their soils.
• Answer key for Pre-lab Questions:
  1. Soil is: minerals, air, water, organic material.
  2. Some soils will drain water faster because they have more space in between soil particles (more air, it is easier for water, nutrients, and pollutants to flow through these spaces).
  3. Sand, or soil with more space will drain faster.
• Answer key for Analysis Questions:
  1. Answers will vary.
  2. Answers will vary.
  3. Answers will vary.
  4. Answers will vary.
  5. Nutrients and pollutants can also move through soil like air – this is important to remember as it means the pollutants can reach ground water, or can affect plants and animals (as well as humans!)

• Answer key for Conclusion Questions:

• Drainage rates are important for farmers, people who build homes, flooding, ponds (if you have a pond that keeps drying up, for instance), pollution, losing nutrients for plants.
• Deserts would have sandy-soils and since it doesn’t rain very often, the plants are adapted to have shallow roots and are more tolerant to less precipitation. The water drains quickly (and evaporation is very high), so the roots are shallow to collect the water as quickly as possible.

Two additional elementary school lab resources available in the AACT Resource Library that are focused on the chemistry of soil investigations are Settle that Soil and The pH of Soil.