Water Quality - Nutrient Management and Cropping Systems - Lesson 13 - Tiling

Water Quality - Nutrient Management and Cropping Systems - Lesson 13 - Tiling

Target Grade Level / Age Range:

Grades 9-12

Time:

50 minutes

Purpose:

Students will understand why farmers use tiling to manage water in their fields.

Materials:

  • Paper
  • Writing utensils

Suggested Companion Resources (books and websites)

Vocabulary (with definitions)

Tile Drainage: Pipe made of perforated plastic, burned clay, concrete, or similar material, laid below the soil surface to a designed grade and depth, to collect and carry excess water from the soil. Also known as a tile drain, farm tile, or field tile

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

Tile drainage is a form of agricultural water management that removes water from the subsurface of the soil. Excess water produces adverse agricultural effects including inadequate root development, soil degradation or compaction, and crop growth inhibition. Additionally, too much subsurface water poses a challenge to farm machinery forcing it to function in non-optimal, muddy conditions. Tile drainage aims to solve these potential problems.

The removal of excess water from the soil profile is controlled through a series of drainage pipes, also known as tile or tubing, that are installed below the soil surface just under the root zone. These subsurface drainage networks then open to a nearby ditch or stream.

Because each field is unique, design and installation of a drainage system requires careful research and planning. Drainage depends on topography, type of crops, and soil variety. These factors then determine the drainage depth and spacing for optimal land improvement.

The most common type of tile is corrugated plastic tubing that has tiny holes to facilitate water entry. When the water table of the soil is higher than the tile, water enters the tubing and as a result lowers the water table, ditching the excess moisture to streams and other outlets.

This field drainage tile process causes many benefits: improved crop quality and production, reduced soil evaporation, well-aerated root systems, timely field operations for early planting, enhanced productivity, and prevention of harmful salt buildup in the soil.

Interest Approach or Motivator

Play the video clip: Laying 8" field drain tile https://youtu.be/njFvJIulMno (slide #2) Ask students what they think is happening in it. Why? Ask students to create three columns on a sheet of paper:

Column 1: What do you Know about the topic? 

Column 2: What do you Want to know? 

Column 3: What did you Learn?

Have students respond to the first prompt in Column 1: What do you know about this topic? Students can do this individually or in small groups. Sometimes it is appropriate to correct false information at this point in the process. Other times, you might want to leave the misconceptions so that students can correct them on their own as they learn new material. Have students respond to the prompt in Column 2: What do you want to know about this topic? Some students may not know where to begin if they don't have much background knowledge on the topic. Therefore, it can be helpful to put the six questions of journalism on the board as prompts (Who? What? Where? When? Why? How?).

Procedures

  1. Show students the summary video of what is tiling (slide #3). Share slides 4-10 and have students capture important information into their notebooks.
  2. Why Tile?
    1. Higher Yields and improved crop quality:
      1. Field drainage improves crop quantity and quality.
      2. Results from over 125 drainage experiments show increases attributed to subsurface drainage: corn by 34%, alfalfa by 42%, soybeans by 29%, and wheat by 76%
    2. Faster Soil Warm-up:
      1. Environmental advantage of a 5-15 degree increase in temperature.
      2. Wet, cold soil is eliminated and surface evaporation is reduced.
    3. Reduced Compaction:
      1. Creates drier soil and reduces the risk of a compaction caused by working wet ground.
      2. Tiled fields stay un-compacted more reliably than non-tiled fields and as a result, produce greater yields.
    4. Larger, Deeper Roots:
      1. Lowered water table causes root systems to seek deeper moisture and creates air and water channels.
      2. This results in better root growth and soil penetration that allows plants to extract more nutrients for longer.
    5. Better Soil Aeration:
      1. Tile plows create soil that percolates better and allows more air and water to reach the roots.
      2. Ideal soil make up is air – 25%, water – 25%, soil – 50%
    6. Favorable Environment:
      1. Opening the soil with drainage plows creates an optimal environment for beneficial soil microorganisms and earthworms.
      2. Aerobic organisms are vital for plant growth and help make nitrogen and sulfur more accessible.
    7. Reduced Yield Variation:
      1. Produces a reliable and consistent increase in yield.
      2. University study showed that un-drained soil saw a 46% fluctuation in yield in comparison with tiled soil that only varied by 18%.
      3. Consistent yield allows for dependable cash flow for farmers.
    8. More Days of Machinery Operation:
      1. Accelerated drying and warmer soil allows for earlier spring planting and longer fall operations.
      2. Dry soil limits compaction and facilitates timely post-emergence applications.
    9. Longer Growing Seasons:
      1. Early planting in warm, dry fields gives plants the maximum opportunity to thrive and produces high yields.
    10. Reduced Yield Variation:
      1. Produces a reliable and consistent increase in yield.
      2. University study showed that un-drained soil saw a 46% fluctuation in yield in comparison with tiled soil that only varied by 18%.
      3. Consistent yield allows for dependable cash flow for farmers.
    11. More Days of Machinery Operation:
      1. Accelerated drying and warmer soil allows for earlier spring planting and longer fall operations.
      2. Dry soil limits compaction and facilitates timely post-emergence applications.
    12. Longer Growing Seasons:
      1. Early planting in warm, dry fields gives plants the maximum opportunity to thrive and produces high yields.
    13. Superior Soil Structure:
      1. Allows field drainage that promotes soil health through soil granulation and root interaction with water and air.
      2. The resultant porous soil retains necessary water for optimal growing.
    14. Increased Dry Year Yield:
      1. Deeper roots enable plants to withstand summer droughts.
      2. Deep roots obtain valuable nutrients before late-summer climate stress.
    15. Reduced Nitrogen Loss:
      1. Creates dry soil that is optimal for nitrogen utilization and thriving aerobic organisms.
      2. Because nitrogen is one of the most expensive inputs, reduced loss allows farmers to save money and produce better crops.
    16. Consistent Seed Stands:
      1. Reduced incidence of seeds rotting before germination and better stands are achieved because of drier soil.
    17. Toxin Removal:
      1. Tiling cleanses soil.
      2. Toxic substances, disease-causing organisms, and dangerously high levels of iron and manganese are removed through better drainage and improved aeration.
    18. Reduced Erosion:
      1. Enhanced field drainage creates soil that can hold extra rainfall, reducing run-off and allowing absorption.
      2. This erosion-control maintains both fertility level and soil structure.
    19. Lower Drying Costs:
      1. Tile drainage allows crops to grow and mature faster and reduces the necessary drying time in the fall.
    20. Lower Machinery Costs:
      1. Allows farmers to be in the fields for more days and for longer during the day during the crop season and harvest.
      2. This efficiency advantage allows farmers to do more with less equipment.
Wrap Up:

Explain that students will pair up and alternate playing two roles: eyewitness and reporter. The eyewitness stands tall and takes on the air of someone who saw a farmer installing tile lines with their very own eyes (a know-it-all with a pleasant personality). The reporter addresses an imaginary camera, with microphone in hand and welcomes the viewing audience to “this breaking news report”. Then the reporter questions the eyewitness about the content just learned in class. For example:

Reporter: We’re here live with [other person’s name], who just witnessed tile lines being installed on a local farm. Please tell us, what did you see or feel as you witnessed this event?

Have students switch roles. The new eyewitness usually picks up where the other left off. If the first eyewitness covered all of the information, then the second starts at the beginning with a new account. If time allows, students can create questions to ask the eyewitness prior to the interview. You can also add a third person to the mix – a news desk anchor – to ask follow up questions to the eyewitness and reporter based on what anchor saw.

Students can review their K-W-L charts and add to column 3: What did you learn? As students record what they have learned, they can review the questions in column 2, checking off any questions that the can now answer. They can also add new questions. Students should also review column one so they can identify any misconceptions they may have held before beginning the unit.

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

Did you know? (Ag facts)

  •  Ideal soil make up is air – 25%, water – 25%, soil – 50%

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

Sources/Credits

Lesson plan development was funded by the Resource Enhancement and Protection Conservation Education Program (REAP CEP). Resource Enhancement and Protection Program (REAP): Invest in Iowa our outdoors, our heritage, our people. REAP is supported by the state of Iowa, providing funding to public and private partners for natural and cultural resources projects, including water quality, wildlife habitat, soil conservation, parks, trails, historic preservation and more.

Author(s)

Will Fett

Organization Affiliation

Iowa Agriculture Literacy Foundation

National Agriculture Literacy Outcomes

  •  Science, Technology, Engineering & Mathematics Outcomes:
    • T4.9-12.d: Evaluate the benefits and concerns related to the application of technology to agricultural systems

Iowa Core Standards

  • HS-PS2-1. Analyze data to support the claim that Newton’s second law of motion describes the mathematical relationship among the net force on a macroscopic object, its mass, and its acceleration. (surface water movement over fields and things like terraces to reduce the speed and force of water)
  • HS-PS2-3. Apply scientific and engineering ideas to design, evaluate, and refine a device that minimizes the force on a macroscopic object during a collision. * (installation of terraces and tiles)
  • HS-ESS2-5. Plan and conduct an investigation of the properties of water and its effects on Earth materials and surface processes. (water cycle, tiling, terracing, bioreact