Geology and Ecology of Soils

Nick Bader,
Whitman College


Soils provide nutrients, water and support for growing plants, host an amazing variety of organisms, and even influence global climate. This class will focus on the dynamic systems in soil and on the interactions between soils and larger ecosystem properties. Course topics will include pedogenic processes, agricultural ecosystems, the interpretation of paleosols, and the role of soils in the global biogeochemical cycling of organic carbon and nutrients.

Course URL:
Course Size:

Course Format:
Lecture only

Institution Type:
Private four-year institution, primarily undergraduate

Course Context:

This is a soils course that is listed as a geology course but does not require introductory geology as a prerequisite, nor do any courses require it. The course is elective and not required for any major. In the past the students have primarily been geology, biology, and environmental studies majors (with an occasional economist or poet).

Course Content:

The course is primarily lecture-based, covering topics in soil science and in ecosystem ecology (soil biogeochemistry). The course also includes a group research project worth 40% of the grade. There is one Saturday field trip that is recommended but not required.

Course Goals:

1. I want students to understand soils as dynamic, living systems with complex hierarchies or organisms, not simply as inert media supporting plant growth.
2. I hope that students with farming or gardening inclinations understand enough about the processes occurring in soil to be able to make intelligent management decisions.
3. Students who begin the course with no research experience will gain proficiency in managing a research project, summarizing the results, and presenting the results to other students.

Course Features:

The first two goals are provided by the lectures. The third goal is due to the research project in which small groups of students carry out a research project on two soils on the Whitman campus. Each group uses a different analysis technique available at Whitman but performs the analysis on the same soil as the rest of the course. The students present their results to the rest of the class on the final day of class, and in doing so put together a more complete picture of the two soils.

Course Philosophy:

The lecture-based design fulfills a need at my institution for non-lab based classes appropriate for majors or non-majors. The research project is a sneaky way to give the students hands-on experience without requiring a three-hour time block each week.


I assess the lectures with four exams, evenly distributed throughout the course. The project is assessed on the basis of the student's presentation to the class and on supplementary materials they turn in.


Syllabus for soils class (Acrobat (PDF) 169kB Apr15 13)

Teaching Materials:

Schedule for soils class (Acrobat (PDF) 56kB Apr15 13)
Soils research project (Acrobat (PDF) 73kB Apr15 13)

References and Notes:

Brady and Weil, Elements of the Nature and Properties of Soils
This text is a condensed version of a standard soil science text. It effectively covers the trickier aspects of the soil science part of the course. I also provide supplemental readings for some topics.