Introduction

As you have learned in previous lessons, there are many different types and orders of soils. These types are determined by soil particle size and the percentage of the soil particle sizes that make up a particular soil. Soil particles come in

  • sand,
  • silt, and
  • clay.

Sand particles are the largest and clay particles are the smallest with silt particles falling in between. Porosity is the amount of space in a given volume of soil. As particle size decreases, the porosity of the soil increases. Permeability is the ability of the soil to allow water to pass through it. Permeability is inversely proportional to soil porosity. As soil porosity increases, soil permeability decreases. In this virtual lab, you will be calculating the porosity and permeability of different soil types by pouring water through a fixed volume of each soil. This information can be used to make predictions about which soils will and will not be good for growing plants.


Clay is not porous, but is not very permeable. So, it tends to hold water more so than sand.

Go to the Task page and complete the Soil Lab.

Lesson Objectives

Following successful completion of this lesson, students will be able to...

  • Identify and describe the porosity and permeability of different soil types as they relate to soil particle size and texture.

Enduring Understanding:

  • Determining the texture of the soil, especially porosity and permeability, can influence the decision of what to grow as well as what to build in or on any particular land.

The above objectives correspond with the Alabama Course of Study: Environmental Science 14

This lesson incorporates the following Literacy Standard: R1, R2, R3, R4, R5, R6, R10, W1, W2, W3, W4, W5, W9, and W10

 

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