Agronomy and Horticulture Department



Soil Genesis and Development, Scenario 3 - Soils and Salts

Date of this Version


Document Type



Plant and Soil Sciences eLibrary (PASSeL) Lesson


Copyright © 2019 Plant and Soil Sciences eLibrary. Used by permission.

This lesson was developed by Martha Mamo, Timothy Kettler, and Dennis McCallister at the University of Nebraska–Lincoln; Jim Ippolito, Research Soil Scientist, USDA-ARS-NWISRL, Kimberly, Idaho, formerly at Colorado State University; Ron Reuter at Oregon State University; Christoph Geiss at Trinity College–Connecticut; and William Zanner at the University of Minnesota. Development of this lesson was supported by the National Science Foundation Course, Curriculum, and Laboratory Improvement Program (NSF-CCLI), Award Number DUE-0042603. Any opinions, findings, conclusions, or recommendations expressed in this publication are those of the authors and do not necessarily reflect the view of NSF.


This case study addresses how soil formed in different parts of the landscape influences productivity in the broad sense of both economic and noneconomic flora and fauna.

The Learning Objectives

  1. Identify the factors of soil formation and distinguish between the active and passive factors.
  2. Describe how soil-forming factors may interact to produce a soil seen in different places in the landscape.
  3. Define the basic chemical and physical processes of soil formation.
  4. Identify the main soil horizons and describe the basic differences between each.
  5. Given information on geographic location, climate, biota, and parent material, predict the soil order that exists at the site.
  6. Identify and describe the roles of soil in the global ecosystem.
  7. Describe and locate human activities that cause soil degradation and/or erosion.

[Lesson map of application scenario on agroecosystems. Highlighted in red on the map are concepts addressed in this application lesson. Image courtesy of UNL, 2006.]