Soil Teaching Resources

Browse printable soil activities, worksheets and more science resources created by teachers for teachers like you!

This collection of resources is aligned with both the TEKS and NGSS curriculums and includes a mix of differentiated and editable options to help you save time on your lesson plans. Each printable and digital resource has been carefully reviewed by a member of our teacher team to ensure it's ready to be used in your classroom!

Looking to better understand this part of the science curriculum, or just looking for fresh ideas to engage your students? Read on for a primer from our teacher team, including a definiton of soil you can share with your class and a look at the different types of soil your students will learn about!

What Is Soil? A Kid-Friendly Definition

Let's start off with a definition for soil that you can use to describe this Earth science term to your students!

Soil is part of the top layer of earth that we dig into, and it's another name for what we often call dirt.

Soil is a vital material because it provides nutrients and support for plants to grow, and it also helps to filter and clean water. Different types of soil have different properties, such as how much water they can hold and how easy they are to dig.

What Is Soil Made Of?

Soil is made up of a huge mixture of things, including minerals, which come from rocks that break down over time, and organic matter, which includes dead plants and animals that have decomposed — or broken down — into tiny pieces. Other things that can be found in soil include air, water and tiny creatures like worms and insects.

How Is Soil Formed?

Soil isn't created overnight. It takes years and years for the process of soil formation — also known as pedogenesis — to happen, and just how long is influenced by a number of factors like climate and the topography of the land. Here's a brief overview of the main processes involved in soil formation:

Weathering

This is the breakdown of rocks and minerals through physical, chemical and biological processes. For example, water and wind can erode rocks, while acids and plant roots can dissolve and break down minerals.

The Breakdown of Organic Materials

Have you ever noticed a bunch of dead leaves that have gathered in one area? If those leaves stay there and continue to be rained on and hit by sun and other weather conditions, eventually they will break down into soil!

Dead plant and animal material come together on the surface of the soil, and it eventually breaks down. This provides a source of nutrients for soil organisms and helps to build up the soil's organic matter content — creating fresh soil.

Composting is a good example of this!

Biological Activity

Organisms such as bacteria, fungi, and earthworms play a vital role in soil formation by breaking down organic matter, releasing nutrients and creating pore spaces in the soil.

What Are the Layers of Soil?

Soil is a bit like a cake with different layers. These layers are called horizons. There are three main layers of soil:

• Topsoil — The top layer of soil is called topsoil. It's made up of a mix of organic matter (like leaves and dead plants) and minerals. This layer is important because it provides plants with the nutrients they need to grow.
• Subsoil — Right below topsoil is a second layer (or horizon) that's made up of larger pieces of rock and minerals. It doesn't have as much organic matter as the topsoil, but it still has some important minerals that plants need.
• Bedrock —  The bottom layer of soil is made up of solid rock. It's not really soil anymore because it's too hard for plant roots to grow through, but it's still important because it's the foundation that holds up the layers of soil above it.

What Are the Different Types of Soil?

There are many different types of soil that your students are bound to encounter in their lifetime, and even the type of soil outside your school is likely to vary based on where it's built. That said, the different types of soil can generally be classified into three main categories based on the size of their particles:

Sand

Sand particles are the largest of the three types of soil particles, usually between 0.05 and 2 millimeters in diameter. Sandy soils drain water quickly and are good for growing plants in dry areas.

This type of soil feels gritty to the touch. You're likely to find sand on a beach and, of course, in a sandbox on the playground.

Silt

Silt particles are smaller than sand particles, ranging from 0.002 to 0.05 millimeters in diameter. This type of soil is smooth like flour, and it's made up of smaller pieces of rock and minerals.

Silt soils have good water retention and nutrient-holding capacity, making them fertile and suitable for many crops.

Clay

Students may think of art class and not soil when they hear the word clay, but this is a type of soil! Clay particles are the smallest of the three types of soil particles at less than 0.002 millimeters in diameter. Clay soils hold water and nutrients very well, but they can be heavy and difficult to work with.

What Is Loam? A Kid-Friendly Definition

Loam is a type of soil that's made up of a mixture of the three main types described above. Loam typically has a balance of sand, silt and clay particles, which makes it especially good for growing plants.

Why Is Soil Conservation Important?

If you're touching on conservation during your soil lessons, it can help to have an explanation of why it's so important. Here's how we explain this to students:

Soil conservation is how we take care of soil so that it stays healthy and doesn't get damaged or washed away. Without healthy soil, we wouldn't be able to grow enough food to feed everyone on the planet, so teaching our students about being good stewards of the Earth includes educating them about conservation.

Soil conservation helps us keep the soil healthy by doing things like planting trees and plants, using compost instead of chemicals and not over-farming.