Soil Conservation Investigation

Soil Conservation Investigation

Target Grade Level / Age Range:

6-8

Time:

Two 60 minutes class periods

Purpose:

Students will identify the different types of farming techniques to conserve soil and be able to visually see the practice in use or test out the conservation practice with a soil erosion experiment.

Materials:

  • iPad/Computers
  • Option A Materials:
    • A stream table box (can be constructed at approximately 16" long by 12" wide by 4" deep or consider purchasing the American Educational Economy Stream Table Kit for $60 found on Amazon.com). This wooden box should be made watertight by either caulking the seams or lining it with materials such as plastic, tin or tar paper. One end of the box should be notched with a V 1.5" deep and a spout attached in the V so that runoff water will flow into your waiting pail.
    • A watering can with 1/2 gallon or larger capacity
    • A plastic protractor
    • A pail to catch the excess water
    • Blocks to elevate the stream table
    • 4 inch squares cut out of dressed 2x4s work well and let you raise the elevation in approximately 1.5 inch increments, and a mop or towels to clean up any spills
    • Different soil types will be needed for the various tests and this may create a need for pails and a trowel or small shovel. Various types of mulch such as hay, pine needles, shredded newsprint or paper will also be needed.
    • A supply of small pebbles, mulch, and other materials are needed for the student to construct a dam for the activity
  • Option B Materials:
    • Soil Conservation BINGO.doc
  • Option C Materials:
    • iPads/tablets with internet connection

Suggested Companion Resources (books and websites)

Vocabulary (with definitions)

  • Water Erosion—Soil loss resulting from the action of moving water
  • Wind Erosion—Soil loss resulting from the action of the wind.
  • Tillage Erosion—the redistribution of soil through the action of tillage and gravity
  • Sheet Erosion—Gradual removal of soil in thin layers by raindrop impact and shallow surface flow.  Results in loss of the finest soil particles.
  • Rill Erosion—Loss of soil in small but visible tracks that are less than 20 cm deep that can be removed by normal cultivation. Develop when surface water concentrates in depressions or low points.
  • Ephemeral Erosion—small channels eroded by concentrated flow that can be easily filled by normal tillage, only to re-form again in the same location by additional runoff events.
  • Gully Erosion—Loss of soil in large, often impassible trenches or ditches resulting from runoff. Channels are deeper than 30 cm and cannot be removed by normal cultivation.
  • Organic Matter—consisting of plant and animal residues at various stages of decomposition, cells and tissues of soil organisms, and substances synthesized by soil organisms.
  • Top Soil—top layer of soil, and is the most fertile part of the land with the most nutrients for growing crops. It is composed of organic matter.
  • Topography—how the land is arranged by natural and physical features of an area (rolling hills, flat prairie land, deep ravines) and how movement of water flows
  • Soil Cover—refers to vegetation, including crops, and crop residues on the surface of the soil.
  • Land Management—process of managing the use and development (in both urban and rural settings) of land resources.
  • Soil Surface Type—smooth, rough, covered, exposed)
  • Primary Tillage—tillage which inverts, cuts or shatters the soil to a depth of 15-36 cm. Usually leaves the soil rough
  • Secondary Tillage—tillage operations that follow primary tillage. The purpose is to prepare a final seedbed that is suitable for planting, seed germination, and weed control
  • Contour Buffer Strips: Narrow strips of perennial vegetation established across the slope and alternating down the slope with wider cropped strips
  • Contour Farming: Farming sloping land (preparing, planting, and cultivating) on the contour and not up and down the slope.
  • Cover Crops: A green crop including grasses, cereal grains, legumes or forbs seeded in the early fall to protect the soil surface from erosion and reduce sediment and nutrient loss during the winter months between growing seasons.
  • Crop Rotation: Growing different revenue-generating crops in a repeated sequence on the same field. Year 1 = Corn, Year 2 = Soybeans, Year 3 = Corn, Year 4 = Alfalfa, Year 5 = Alfalfa
  • Nutrient Management: Careful management of the amount, source, placement, form and timing of the application of plant nutrients and soil amendments.
  • No-Till Farming: Soil and residue is left undisturbed from harvest to planting. No full-width tillage operations are done.
  • Field Borders: a band or strip of perennial vegetation established on the edge of a cropland field.
  • Grassed Waterways: broad, shallow and typically saucer-shaped channels designed to move surface water across farmland without causing soil erosion.
  • Terraces: Manmade structures that follow the contour of a hillside, breaking a long slope into smaller segments.
  • Windbreaks: Line/row of trees or hedges that provides shelter or protection from the wind.
  • Bioreactors: An underground trench of woodchips at the end of a tile line. Water from the tile flows through the woodchips before entering a stream or river.
  • Highly Erodible Land (HEL): Land which has the potential for long term annual soil losses to exceed the tolerable amount by eight times for a given agricultural field, as defined by USDA Natural Resources Conservation Service

Background – Agricultural Connections (what would a teacher need to know to be able to teach this content)

Ways to Reduce Soil Erosion through   Conservation Practices:

  • Contour Buffer Strips: Narrow strips of perennial vegetation established across the slope and alternating down the slope with wider cropped strips
  • Contour Farming: Farming sloping land (preparing, planting, and cultivating) on the contour and not up and down the slope.
  • Cover Crops: A green crop including grasses, cereal grains, legumes or forbs seeded in the early fall to protect the soil surface from erosion and reduce sediment and nutrient loss during the winter months between growing seasons.
  • Crop Rotation: Growing different revenue-generating crops in a repeated sequence on the same field. Year 1 = Corn, Year 2 = Soybeans, Year 3 = Corn, Year 4 = Alfalfa, Year 5 = Alfalfa
  • Nutrient Management: Careful management of the amount, source, placement, form and timing of the application of plant nutrients and soil amendments.
  • No-Till Farming: Soil and residue is left undisturbed from harvest to planting. No full-width tillage operations are done.
  • Field Borders: a band or strip of perennial vegetation established on the edge of a cropland field.
  • Grassed Waterways: broad, shallow and typically saucer-shaped channels designed to move surface water across farmland without causing soil erosion.
  • The vegetative cover in the waterway slows the water flow and protects the channel surface from the eroding forces of runoff water.
  • Terraces: Manmade structures that follow the contour of a hillside, breaking a long slope into smaller segments.
  • Windbreaks: Line/row of trees or hedges that provides shelter or protection from the wind.
  • Bioreactors: An underground trench of woodchips at the end of a tile line. Water from the tile flows through the woodchips before entering a stream or river.

Interest Approach or Motivator

Using an electronic device with internet, use the satellite view function of Google Maps to look at a local farm. Look at surrounding farms and have students compare the farms on Google Maps with each other. Have them identify similarities and differences of the farms. Discuss with the students why the fields look different? (Topography, Location, Conservation Practices)

Procedures

  1. Using the Soil Conservation Graphic Organizer have the students use the following websites to fill out the document.
    1. Iowa State Extension:  http://www.extension.iastate.edu/agdm/crops/html/a1-41.html
    2. NRCS:  http://www.nrcs.usda.gov/wps/portal/nrcs/detailfull/null/?cid=nrcs143_026849
  2. Go over the worksheet and discuss the different types of soil conservation practices.

Pick one or more of the three options for an experiential learning activity for soil conservation.

Option A: Experiment with a soil erosion table.

  1. Objective: students will observe soil erosion by the force of water. They will then use the information of different soil conservation practices to create a solution to controlling water-induced topsoil erosion with different soil types.
  2. Allow 45 minutes or more for activity.
    1. Set the stream table at an elevated height that erosion takes place (can be determined by trial and error).
    2. Fill the stream table with different types of erodible soil (sand, clay/loam, loam, silt loam).
    3. Note: Water is added to the upper end of the stream table and flows downhill. This will create erosion and runoff so make sure there is a pail at the end of the stream table to catch excess flow.
    4. Depending on the different erodible soils used will determine the types of erosion created. Sheet, rill, and gully erosion can be studied by the flow of water down the table.
    5. Have students observe the types of erosion taking place and take notes of observations.
    6. Have the class share observations and then break into pairs or groups of three. Each group’s task is to create a solution to the soil erosion observed in the experiment as well as learned about in the presentation.
      1. First have the group draw out a plan of their proposed idea to reduce soil erosion.
      2. After they have your approval of their plan, provide them with resources to create their concept and test it on the stream table.
  3. To end class, have a “ticket out” or a “ticket in” to the beginning of the next class.
    1. Have the students reflect on their concept and how it held up in the stream table test. Have them reflect on what went well in their concept and what needs improvement.
    2. Have them explain what they found interesting or disappointing in the experiment. And lastly any questions they still might have about soil erosion.

Option B: Contact your local DNR or NRCS for guest speakers or field trip locations.

  1. If you decide to go on a field trip, have students play Conservation BINGO as they are riding on the bus. See ConservationBINGO
  2. Students each get a BINGO card and as they are traveling on the bus they should look out the window to search for conservation practices. When they find a conservation practice they can mark it on their card.

Option C: FarmChat® a local farmer or go to the farmer to see the different soil conservation practices in action.

Essential Files (maps, charts, pictures, or documents)

Did you know? (Ag facts)

  • 30.6 million acres farmed in Iowa
  • Number of farms (2012): 88,637
  • Acres in farmland (2012): 30,622,731
  • Implementing erosion control practices is one of the most effective ways to protect the soil and land that grows our food.
  • 5 tons/acre/year of soil loss is the maximum tolerable loss for soil in Iowa

Extension Activities (how students can carry this beyond the classroom)

  • Have students write a letter to an area farmer to encourage them to adopt the No-till conservation practice.
  • In groups of three have the student take three pictures of good farming techniques in and around their local community.  If the students can find bad farming techniques, they should also take pictures.

Sources/Credits

Authors

Brian Ungerer and Hannah Pagel

Organization Affiliation

Central Community School District

Iowa Agriculture Literacy Foundation     

National Agriculture Literacy Outcomes

  • T 1.6-8b. Describe benefits and challenges of using conservation practices for natural resources (e.g., soil, water, and forests), in agricultural systems which impact water, air, and soil quality
  • T 1.6-8c. Discover how natural resources are used and conserved in agriculture (e.g., soil conservation, water conservation)

Iowa Core Standards

  • MS–ESS3–3 Apply scientific principles to design a method for monitoring and minimizing a human impact on the environment.
  • MS–ESS3–4 Construct an argument supported by evidence for how increases in human population and per-capita consumption of natural resources impact Earth’s systems.

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