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DIG IT - The Secrets of Soil



Materials are no longer available for sale.

Please visit UN - DIG IT - Secrets of the Soil student booklets in 8 languages

website to view and download in PDF format.

Is soil an important ingredient in your every day life?

The answer is yes, and here are a few reasons why:

Last night you slept in a building built on soil.

You drink waterthat flows through soil and is cleaned by the soil.

You breathe air that comes partly from plants growing in the soil.

You even wear clothes made from plantsthat grow in the soil.

  • Soils make our lives possible. We build on them, play on them, drive on them, eat food grown in or raised on them, take medicines from them, wear clothes we wouldn’t have without soils, drink water that wouldn’t be clean without soils, breathe air we wouldn’t have without the plants and trees growing in soils. The entire earth—every ecosystem, every living organism—is dependent upon soils.


A Few Facts about Soil

  • Soil makes up the outermost layer of our planet.
  • Topsoil is the most productive soil layer.
  • Soil has varying amounts of organic matter (living and dead organisms), minerals and nutrients.
  • Five tons of topsoil spread over an acre is only as thick as a dime.
  • Natural processes can take more than 500 years to form one inch of topsoil.
  • Soil scientists have identified over 70,000 kinds of soil in the United States.
  • Soil is formed from rocks and decaying plants and animals.
  • An average soil sample is 45 percent minerals, 25 percent water, 25 percent air and five percent organic matter.
  • Different-sized mineral particles, such as sand, silt, and clay, give soil its texture.
  • Fungi and bacteria help break down organic matter in the soil.
  • Plant roots and lichens break up rocks which become part of new soil.
  • Roots loosen the soil, allowing oxygen to penetrate. This benefits animals living in the soil.
  • Roots hold soil together and help prevent erosion.

Information provided by U.S. Dept. of Agriculture, Natural Resources Conservation Service and listed on the Environmental Protection Agency website at http://epa.gov/gmpo/edresources/soil.html.


Soils Education Materials

NACD worked with the Smithsonian and Soil Science Society of America in the development of soils materials to compliment the “Dig It! The Secrets of Soils” exhibit at the Smithsonian National Museum of Natural History (http://www.forces.si.edu/soils/). The soils education materials were designed to teach students (K-8) as well as adults about the importance of soils in their everyday lives. The exhibit was in Washington, D.C. until January 2010. The exhibit has been traveling since 2010 to Nebraska; Spokane, Washington Minnesota, Iowa, California and North Carolina.  Contact Susan Schultz This email address is being protected from spambots. You need JavaScript enabled to view it.



Soils Activities and Resources

Soils Educators Guide (1.2 MB, PDF) - This online interactive guide is full of great resource to use in a classroom or other educational programs. It contains activities, science standards that complement the Dig It! student booklets, literature connections, links to additional soils outreach materials and more. The printed educators guideis also available in quantities of ten from the NACD Marketplace.

Soil Activity Worksheets (linked below) - The K-7 soils education worksheets listed below complement the Dig It! student booklets or are great for use with soils outreach programs.

Soils Topic Book List (PDF) - Looking for books to read to students or add to your library collection? Download this list of books that will give students a better understanding of soils in their everyday life.

Fun Facts about Soil and Worms (PDF) - Use these fun and informative facts as part of an exhibit or question and answers with student or adults. This activity covers the importance of worms and our soil.


Additional Soils Resources

Dig It! Logo and Soils Images - Several images that go along with the 2009 Stewardship theme,"Dig It! The Secrets of Soil," use on your website, promotions or publications.

Smithsonian DIG IT! The Secrets of Soil Exhibit

News Article: "DIG IT! Soils Takes Center Stage at Smithsonian" (PDF)

Scoop on Soil

This site has a variety of soil education information from USDA-NRCS and University of IL Exension including fundamental soil concepts, soil biology printer, soil quotes, a help stop soil erosion activity and more.

Dr. Dirt! - Great selection of hands on soil activities to share with students.

Soil Paint Recipe | PDF |

Soil Presentations - Keep the attention of the students and community members you are educating through these catchy presentations on soils!

Soil Texture Lesson - A soil texture lesson, a soil texture analysis experiment and an accompanying PowerPoint presentation are available from the Utah Ag In the Classroom program.

Soil Color Lesson - A soil color lesson, a soil crayons experiment and an accompanying PowerPoint presentation are available from the Soil Science Society of America. 

FAOInfographicIYS2015Food and Agriculture Organization of the United Nations Soil Infographic |PDF|









Water is Life