Explore: Challenges to Soil

Big Idea 2. As the human population increases it is even more important that we care for the soil.
Essential Question: What are the big challenges to soil health and sustainability?
Once students have engaged with the importance of soil health to society, move on to the three big challenges: desertification, salinizationThe process whereby soluble salts accumulate in the soil., and deforestation. 

Teachers can choose one of two approaches to explore human impacts on soil.

Option 1. Expert Teams: Challenges to Soil

Break students into two or three "Expert Teams" give each group one environmental challenge to research. Challenges include desertification, salinization, and deforestation. Resources and descriptions are listed below.

Option 2. Case Studies

Choose one of the challenges to focus on as a class, then allow students to follow-up with a second case on their own.

Questions to investigate:

• What is the cause of the challenge?
• What systems are impacted? (soil, air quality, water quality, habitat)
• Give several examples of locations where this challenge is occurring.
• List and explain solutions to the problem. How has technology been incorporated into the solution?
• What are the economic, environmental, and human trade-offs?

In order to learn about their selected challenge, students complete one or more of the following activities. Activity descriptions, linked below, include detailed student instructions.

Challenges to Soil

Challenge: Deforestation

Case: Amazon Rainforest ESRI GeoInquiries – 06_Tropical Deforestation: Students use GIS maps and images to identify and describe the locations most affected by deforestation. Tropical Deforestation GIS activity 
Written for AP Environmental Science
Time required: 15-20 minutes to complete the GIS exercise. 

Alternate / Additional Sources of Information:

Case Studies in Education: The Deforestation of the Amazon A Case Study in Understanding Ecosystems and Their Value The Deforestation of the Amazon Students read the case and through a role-play of various stakeholders evaluate land-use decisions. 
Time required: several class periods. 
GIS Story Map -- A World Of Forests A World Of Forests 
Time required: 15- 20 minutes to review

Challenge: Salinization

Case: Australia Lab Activity: Salinization Read the article (s) and complete a hands-on salinity lab 
Time required:  
30 minutes to read article, several class periods to complete the labs. 

Article: Soil Salinization and Crops describes issues with soil salinization in Australian crop yields. 
Soil Salinization Lab for APES Includes precise instructions for conducting a controlled laboratory experiment. Students investigate the impact of saltwater on seed germination. Soil Salinization Lab 

Alternate Lab Salinization Lab - Student Template 
This inquiry-based lab has three scenarios to set up the salinization lab. Salinization Lab

Challenge: Desertification

Case: Aral Sea
ESRI GeoInquiries – 05_Down to the Last Drop 
Written for AP Environmental Science 
Students use GIS maps and images to explore the consequences of human actions on water resources and examine the health impacts of availability to clean water. 
Time required: 15 minutes 

Alternate / Additional Activities and Information 
Case: Dust Bowl 
ESRI GeoInquiries – 10_ Dust Bowl (Note: this case was also included in chapter 6 TG) 
Written for US History
This GIS activity explores the impacts of the dust bowl on human settlement patterns. Students explore the Dust Bowl region using population change, agriculture, and precipitation data. 
Time required: 15 minutes 

EarthLabs Drought 
Time required: 2 hours (can be completed as homework)
In this activity, students watch a PBS video and/or interact with the video's companion website. They also examine maps and animations that show the distribution of drought patterns over the past 300 years; these maps were reconstructed from environmental records. Finally, students examine the amount of time different areas spend in drought.