Title: Managing Soils on My Farm


  1. Students in the Agricultural Production and Management I course (10th grade).
  2. 9th grade course included basic terminology related to soils and conservation of natural resources, but student have had no specific instruction on soils.
  3. Half of the students in the course live on farms or have parents that work on farms.
  4. Soil erosion and conservation is a major concern in the area.
  5. Local practices include farming highly erodable land.

Teacher Objectives: After completing this lesson students will be able to:

  1. List and describe major factors affecting soil formation.
  2. Describe physical properties of soils including color, texture, structure.
  3. Describe soil profiles and their significance in production agriculture.
  4. Classify soils using the NC soil classification system.
  5. Select appropriate management practices for a given soil and site.

Teaching Procedures

  1. Interest Approach


  1. Bring samples of three soils into the classroom: a sandy soil, a dark organic soil, and a red, clay soil.
  2. Ask students to describe the soil. (most will choose to describe by color)
  3. Allow a student to feel the soil and to describe the way the soil feels.

Mental Set:

  1. Ask the students if they could find soils like these samples on their farms or in their yards.
  2. Ask students to give reasons they believe some soils are more fertile than others.

Create Uncertainty (leads to felt need to know more): Lead questions (do not acknowledge correct responses):

  1. What are some major differences between soils? (wait until someone mentions texture or feel)
  2. What causes differences in the way soils feel?
  3. What implications does texture have for using the soil for crop production?
  4. How does texture affect the ability of a soil to produce crops?

Transition statement: Texture is one of the important factors that we will study that determine how we will use soils effectively. There are other important considerations as well. Before we learn about the other factors, let's discuss why we should learn more about soils.

  1. Group Objectives:

Lead Questions:

  1. Why is it important to know something about soils?
  2. How will we benefit from learning more about soils?

Anticipated Group Objectives:

  1. So we will be able to conserve a valuable natural resource.
  2. To be able to plant the right crops on the best sites.
  3. To maximize profits on our farms.
  1. Problems and Concerns

Lead Questions:

  1. What do you need to know about managing soils?
  2. What information is needed to determine the types of soils you have?

Anticipated Problems and Concerns:

  1. What causes differences in the soils in our area?
  2. How are soils classified?
  3. What determines soil fertility?
  4. How do we determine the best use for a soil?
  5. What practices can be used to conserve soils?
  1. Problem Solutions: (For this Sample Lesson Plan, only one problem solution will be presented as an example. For a complete plan, problem solutions would be developed for each problem and concern.)

Problem and Concern #1: What causes differences in the soils in our area?

Trial Discussion: Ask students to give possible reasons for differences in the soils. (Determine what is already known by the students)

Presentation: (Use PowerPoint presentation)

A. Five Major Soil Factors Affecting Soil Formation

1. Active Factors: Climate and Biological Activity

2. Passive Factors: Parent Material, Topography, Time

  1. Active Factors
    1. Climate--two major factors: temperature and rainfall
    1. Temperature affects:
    1. rate of chemical activity--chemicals in the soil break rocks into soil particles
    2. type of vegetation--warmer climates produce more vegetation and faster decay
    3. freezing and thawing--increases rate at which rocks are broken into soil
    1. Rainfall
    1. Leaching--high rainfall levels increases the movement of nutrients down through the soil
    2. Movement of clay particles--rain moves soil particles through the soil profile.

2. Biological Activity

    1. Macroorganisms--living and dead (larger plants and animals)
    1. Provide organic matter for the soil
    2. Plants are the largest source of organic matter
    3. Animals are a secondary source of organic matter--animal waste and decomposing carcasses.
    4. Create channels through the soil (roots, by plants; burrows by animals)
    1. Microorganisms--microscopic plants and animals
    1. Aid in the decomposition of plants and animals.
    2. Serves as "glue" for soil particles
    3. Minor source of organic matter when these organisms die

Passive Factors:

3. Parent material--original geologic material

    1. Residual parent material--formed from rocks located at the site
    1. Some rocks weather (break down) faster than others, e.g. sedimentary rocks such as limestone and shale weather faster than quartz and granite.
    2. Some soils have organic parent materials—usually wet sites, such as peat bogs, or large swamps.
    3. Minerals in the parent material give the soil a distinct color and texture.
    1. Transported parent materials--formed at one location and moved to another site
    1. Colluvium--parent materials relocated due to slopes
    2. Alluvium--soils deposited by overflowing streams
    3. Loess--soils deposited by wind
    4. Glacial till--rocks and gravel deposited by receding glaciers.

(Note: Obtain samples of common soil-forming rocks and minerals. Discuss what processes must happen to change these parent materials to soil.)

4. Topography--landscape

    1. Influence on soil formation:
    1. drainage--wet soils tend to slow down biological activity
    2. runoff--increases action of water on parent materials
    3. erosion--moves soils from one site to another
    4. sunlight--heat on rocks increases breaking up of parent material
    5. wind--relocates soil particles

5. Time--factor that determines soil profiles

    1. Creates layers in the soil
    2. Soils deposited by floods are "young" soils, and are actually still forming.

(Note: Discuss how different layers in the soil profile might be formed)

Interactions Between Soil Forming Processes

Processes act together, not independently to form soils:

  1. Climate acts immediately on parent material and organic matter.
  2. Physical weathering decreases the size of parent materials and changes composition of minerals.
  3. Leaching of soils removes salts and calcium.
  4. Plants and animals add organic matter and add humus.
  5. Increase channels through the soil caused by plant roots and animal burrows allow more leaching and weathering of soils.
  6. Horizons begin to develop below the soil surface as a result of leaching and deposits of organic matter (or lack of organic matter).
  7. Clay particles tend to solidify at certain levels in the soil.
  8. Rate of water movement decreases and leaching decreases.
  9. Changes in soil occur at a slow rate.

Summary and Conclusion:

Two different sites on a farm are presented. Which will result in faster soil formation and why?

A field is located on a slight slope with a northern exposure. The parent material is limestone and is fairly close to the surface of the soil—approximately 24 inches deep. The field is in pasture that is grazed by cattle.

Another site on the farm is completed wooded and covered with mature hardwood trees. It is flat land, but not located near a stream. The parent material is limestone and is located approximately four feet below the surface.

(Next Problem Solution)

Problem and Concern #2: How are soils classified?


(Follow the same process in developing the problem solution for this problem and concern and the others that follow)


Evaluation (Note: in an actual lesson plan, each of these evaluation items would be shown. At this point, the actual document is not required because we have not discussed evaluation).

  1. Daily quiz on soil formation.
  2. Quiz on soil classification
  3. Lab activity on soil classification.
  4. Unit test on all problems and concerns.


Donahue, R.L. and Follett, R.H. Our Soils and Their Management. Danville, IL: Interstate Publishers, Inc.

Plaster, J.E. Soil Science and Management, 2nd ed. Albany, NY: Delmar Publishers, Inc.

North Carolina Soil Classification Handbook, NC Cooperative Extension.