- How human actions cause soil erosion
- Ways to prevent soil erosion
- Identify human actions that increase soil erosion.
- List ways to reduce soil loss.
contour cropping: planting crops in curved rows to follow the contour of hills in order to reduce runoff and soil erosion
cover crop: crop that is planted to cover and protect the soil from erosion during seasons when other crops do not grow
no-till planting: planting crops without plowing first, so the soil is not disturbed and dead plants remain to protect the soil from erosion
strip cropping: planting strips of groundcover plants between fields of crops to reduce runoff and soil erosion
terracing: building step-like terraces on slopes for planting in order to reduce runoff and soil erosion
windbreak: row of trees planted between fields to slow down the wind and reduce soil erosion
Introducing the Lesson
Use the apple peel demonstration at the following URL to introduce students to the limited amount of soil on Earth. Using an apple to represent planet Earth, you will cut progressively smaller pieces of peel until you have a very small sliver of peel that represents the total amount of soil on the planet. Tell students they will learn how soil is lost and how the loss can be prevented when they read this lesson.
Building Science Skills
The URL below contains five soil erosion activities. In the activities, students can identify erosion problems at their school and propose solutions. They can also investigate different types of soil erosion through hands-on classroom activities. In addition, they can research erosion in depth and involve their parents in erosion activities.
In the activity at the following URL, students will demonstrate the impact of soil erosion using a soil profile. The PDF document provides a detailed lesson plan, student worksheets, and all other materials needed for the activity.
Work with students to make a cluster diagram of human actions that accelerate soil erosion. You can make the diagram on a chalkboard, whiteboard, or overhead transparency. Surrounding a central circle labeled “Human Actions and Soil Erosion,” add circles labeled with each of the following: “Growing Crops,” “Grazing Animals,” “Logging,” “Mining,” “Construction,” and “Recreation.” Call on students to contribute important details to each of the surrounding circles.
Some students may be interested in reading first-hand or fictional accounts of people who experienced the Dust Bowl. Some recommendations are listed below. Ask the students to write a short book review and share it with the class.
- Voices of the Dust Bowl (2012), by Sherry Garland
- Survival in the Storm (2002), by Katelan Janke
- Out of the Dust (2005), Karen Hesse
- No More Tears, No More Tears! (2011), by Chloe Noble Kavanaugh
If you do the demonstration described in the URL below, you will create an apparatus to simulate soil erosion by water. Then you will use the device to demonstrate how various mulches and organic soil additives affect the amount of soil that eroded. Before you test each type of mulch or additive, have students predict how well they think it will reduce soil erosion. They can determine if they are correct by observing the water that collects from the device. They should infer that darker colored water contains more eroded soil.
A common misconception is that erosion is the process by which weathered particles are deposited in a new location. Explain to students that erosion is the transport, or movement, of particles but it does not involve the settling and accumulation of particles in a new location. The process by which particles are deposited and build up in a new location is called deposition. Deposition is responsible for creating sand dunes, deltas, alluvial fans, loess deposits, and some mountains.
Reinforce and Review
Copy and distribute the lesson worksheets in the CK-12 Earth Science for Middle School Workbook. Ask students to complete the worksheets alone or in pairs to reinforce lesson content.
Lesson Review Questions
Have students answer the Review Questions listed at the end of the lesson in the FlexBook®.
Check students’ mastery of the lesson with Lesson 19.1 Quiz in CK-12 Earth Science for Middle School Quizzes and Tests.
Points to Consider
Increasing soil erosion isn’t the only way that human actions can affect the land. Many human actions also pollute the land. What is pollution?
What human actions might pollute the land?