Unit 1.2: Role of Soil

Introduction

In this lesson we will focus on soil, the "heart" of the Critical Zone. Soil consists of mineral and organic matter derived from a variety of sources and it is vitally important to sustaining life on Earth, including human society. You will learn that soils are not randomly distributed about our planet, but instead occupy space determined by the overlapping domains of the state factors of soil formation. Ultimately, soil records the overlap of atmospheric, lithospheric, hydrologic, and biologic processes, the innermost workings of the CZ. Finally, you will consider the distribution of soils at a site chosen by you and cleared with your professor, and the implications of the distribution to understanding CZ processes and land use at the site. You will accomplish this using an online resource. In this unit, you will:

• recognize soil as a socially relevant mineral and biotic entity
• identify the five state factors of soil formation and basic information regarding their importance, and apply that knowledge to a site
• discuss how soils are described and classified into twelve soil orders and how those soil orders are geographically distributed
• explain five of the major threats to healthy soils
• apply information from the Web Soil Survey to land-use planning and decision making.

Unit 1.2: Role of Soil

Part 1 - Examining Soil

Pre-class

• Read McCauley, Jones and Jacobsen (2005) (reference below) and Brady and Weil (2002) (reference below) and browse the following website prior to class to learn about soil characterization protocols, soil horizon, soil texture, soil color, and soil structure:http://www.globe.gov/do-globe/globe-teachers-guide/soil-pedosphere?p_p_id=globegovteacherguideportlet_WAR_globegovcmsportlet_INSTANCE_5esR&p_p_lifecycle=0&p_p_state=normal&p_p_mode=view&p_p_col_id=column-1&_globegovteacherguideportlet_WAR_globegovcmsportlet_INSTANCE_5esR_protocolCat=372023.

In-class

Soil study

• A lecture focusing on "state" factors of soil formation will serve to review the material covered in the pre-class reading assignment will lead into the class watching a few short videos that describe field activities involving soil study and soil properties; soil horizons, boundaries and transitions; soil color and texture; and soil moisture:
  • YouTube Training Videos with Tim White and Ashlee Dere:
    • Earth 530: Soil Study with Ashlee Dere, Part 1 - Central PA Soil Study (4:30)
    • Earth 530: Soil Study with Ashlee Dere, Part 2 - Studying the Soil (6:42)
    • Earth 530: Soil Study with Ashlee Dere, Part 3 - Assessing Soil Color (5:41)
    • Earth 530: Soil Study with Ashlee Dere, Part 4 - Studying the Soil (4:26)
• You will browse some websites to examine soil erosion and threats to soils and then use a think-pair-share format to lead the way into a a class discussion regarding the impacts of soil erosion on multiple areas of the Critical Zone.

Homework 

• Browse "12 Soil Orders" website to learn about how we classify soils in the U.S., as well as the Compendium website to learn how other nations approach the description and classification of their soil resources. You should also study the global map of the distribution of soils. Then address the following 3 questions (typed, ~2 pgs dbl spaced) based on the two websites above:

1. Do you observe any generalized pattern to the distribution of any of the soil orders?
2. If so, can you attribute the distribution to any understanding you may have of the state factors of soil formation?
3. Can you draw any conclusions regarding the relative importance of any of the state factors of soil formation from your observations?

Part 2 - Soil Surveying and Mapping

In-class

Class Discussion

• Think-pair-share review of three questions from the soil classification website assigned as homework after last class period. Then you will look at the WebSoilSurvey website to learn how the tool works and how it can be used to address land-use planning and decision making.

WebSoilSurvey Activity

• Use the NRCS WebSoilSurvey http://websoilsurvey.sc.egov.usda.gov/App/HomePage.htm (Note: you have to disable blocked pop-up windows for this to work) website to do soil surveying, mapping, and land-use planning. Coupling the reading with the WebSoilSurvey, review the information derived from the NRCS SoilSurvey web site to assess or infer the following factors. Be sure to cite each separate report that you reference when answering these questions. A final report from this exercise should include a soil map of the chosen study site with either a description of the site location or a larger scale map in which the site can be located and the following information:
  • The dominant soil type at the study site?
  • Any characteristics of the dominant soil that effect land use and whether or not the effect is positive or negative?
  • Whether or not the state soil exists at the study site? If not, where is the closest location where the state soil is mapped?
     
  • A brief description of the importance of the state factors in the formation of the dominant soil at the study site. Compare/contrast the dominant soil to the state soil.(see NRCS State Soil info: http://www.nrcs.usda.gov/wps/portal/nrcs/detail/soils/edu/?cid=stelprdb1236841)
  • What are the primary threats to soil at the site?
  • Optional:Are there any soil exposures located at the study site? If so, what soil type is exposed? If not, where is the closest soil exposure to your study site? Include a photograph of any soil exposures you visit.
  • The following activity sheet may help to guide development of your reports: WebSoilSurvey Activity Sheet (Microsoft Word 2007 (.docx) 32kB Dec23 16)

Additional Resources

• McCauley, Jones and Jacobsen (2005). Basic Soil Properties, Soil & Water Management Module 1, Montana SU Extension, Pub#4481-1, 12 pgs
• Brady, N. C., and R. R. Weil (2002). Formation of Soils from Parent Materials. In The Nature and Properties of Soils (13th ed., pp. 39–64). Upper Saddle River, N.J.: Prentice Hall.
• Soil Characterization protocols:
  • Earth 530: Soil Study with Ashlee Dere, Part 1 - Central PA Soil Study (4:30)
  • Earth 530: Soil Study with Ashlee Dere, Part 2 - Studying the Soil (6:42)
  • Earth 530: Soil Study with Ashlee Dere, Part 3 - Assessing Soil Color (5:41)
  • Earth 530: Soil Study with Ashlee Dere, Part 4 - Studying the Soil (4:26)
• University of Idaho 12 Soil orders website: https://www.uidaho.edu/cals/soil-orders
• UCDavis Soilweb in Integrate Sustainable Agriculture Module activity Using SoilWeb to Investigate the Soil Beneath You
• Compendium website: http://www.css.cornell.edu/faculty/dgr2/research/sgdb/sgdb.html
• Global map of the distribution of soils: http://www.teachersdomain.org/resource/ess05.sci.ess.earthsys.soils/
• Soil Erosion website: http://soilerosion.net
• Threats to soils website: http://www.enviroliteracy.org/article.php/244.html
• NRCS WebSoilSurvey: http://websoilsurvey.sc.egov.usda.gov/App/HomePage.htm
• Soil, Not Dirt: A Digital Journey Connecting Soils, Plants, and Climate YouTube video by Rebecca Lybrand: https://www.youtube.com/watch?v=3JarDy53PLQ