Target Grade Level / Age Range:

Grades 9-12

Time:

50 minutes

Purpose:

Nutrient pollution is one of America's most widespread, costly and challenging environmental problems, and is caused by excess nitrogen and phosphorus in the air and water. Runoff surface water is one way nutrients get into our water systems and cause pollution. Not only is it important to understand the implications of runoff but also to know the sources of runoff and solutions used to reduce the impact of runoff in our environment.

Materials:

  • Tablet or computer with internet access
  • Pencil and Paper
  • Solutions to Runoff Management PowerPoint
  • Optional: Materials to construct student’s concept for the runoff solution for activity

Suggested Companion Resources (books and websites)

Vocabulary (with definitions)

  • Point source pollution: A collective term for contaminants which originate from a specific point, such as an outfall pipe. Point sources are generally regulated by an NPDES permit
  • Nonpoint source pollution: A collective term for contaminants which originate from diffuse sources, such as a farm field
  • Storm flow/storm water: The fraction of discharge (flow) in a river which arrived as surface runoff directly caused by a precipitation event (rain). Storm water generally refers to runoff which is routed through some artificial channel or structure, often in urban areas.
  • Edge of field (water) monitoring: collection of water samples either from surface runoff or subsurface flow (tile flow), typically used to track performance of a best management practice
  • Best management practice (BMP): a general term for any structural or upland soil or water conservation or crop production/land use practice. Examples of conservation practices and structures include terraces, grass waterways, sediment retention ponds, reduced tillage systems, etc. For crop production, BMPs could include fertilizer form, application rates, timing and method, adjusted for crop needs and soil test levels.
  • Iowa Nutrient Reduction Strategy: a science and technology-based framework to assess and reduce nutrients to Iowa waters and the Gulf of Mexico. It directs efforts to reduce nutrients in surface water from both point and nonpoint sources in a scientific, reasonable, and cost-effective manner. The Iowa strategy is a coordinated approach for reducing nutrient loads discharged from the state’s largest wastewater treatment plants, in combination with targeted practices designed to reduce loads from nonpoint sources such as agriculture.
  • Runoff: when rain hits saturated or impervious ground and flows overland downhill to a stream, lake, or watershed.
  • Algal Blooms: Large growth of algae in an ecosystem

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

Runoff surface water is one of the leading factors to current environmental issues. Knowing how runoff contributes to our water sources is the first way to identify a solution to the issue at hand. The next way to runoff management is understanding the difference in point and nonpoint sources of runoff. This helps determine if there is a direct effort that can be made to reduce runoff or not. After we determine the source we can then work to make the best management decision to reduce runoff in an operation.

Interest Approach or Motivator

  1. Review with students what they have learned about the previous lessons.
  2. Review the water cycle and how that contributes to runoff
  3. Give a brief review of runoff and ask students what they think runoff can lead to or problems that are a result of runoff.           

Procedures

  1. Using the Solutions to Runoff PowerPoint, present information to students.

What is Runoff?

  • Runoff: when rain hits saturated or impervious ground and flows overland downhill to a stream, lake, or watershed.

What is the Problem?

  • Nutrient pollution is one of America’s most widespread, costly and challenging environmental problems.
    • Caused by excess nitrogen and phosphorus in the air and water.
    • Too much nutrients in soil, water, and air leads to environmental and human problems

Nutrient Runoff Found in Water Sources

  • Nitrogen and phosphorus are nutrients that are natural parts of aquatic ecosystems
    • Both nutrients support the growth of algae and aquatic plants, which provide food and habitat for fish, shellfish and smaller organisms that live in water
    • When too much of certain elements enters the ecosystems it can cause pollution
  • Too much nitrogen and phosphorus in water causes algae to grow faster than an ecosystem can handle.
    • Large growths of algae are called algal blooms and they can severely reduce or eliminate oxygen in the water, leading to illnesses in fish and the death of large numbers of fish.
      • Example: The Hypoxia in the Gulf of Mexico or Cape Cod

Nitrogen

  • Most abundant element in the air we breathe
  • Nitrogen constitutes 78 percent of Earth's atmosphere and is a constituent of all living tissues.
  • Vital to plant growth because it is a major component of photosynthesis
  • The greatest single commercial use of nitrogen is as a component in the manufacture of ammonia, subsequently used as fertilizer
  • Nitrogen molecules occur mainly in air. In water and soils nitrogen can be found in nitrates and nitrites.
  • In its gas form, nitrogen is colorless, odorless and generally considered as inert.
  • In its liquid form, nitrogen is also colorless and odorless, and looks similar to water

Phosphorus

  • Phosphorus is noted especially for its role in capturing and converting the sun's energy into useful plant compounds.
  • Is a vital component of DNA, the genetic "memory unit" of all living things.
  • Also a component of RNA, the compound that reads the DNA genetic code to build proteins and other compounds essential for plant structure, seed yield and genetic transfer.
  • Is essential for specific growth factors that include
    • Stimulated root development
    • Increased stalk and stem strength
    • Improved flower formation and seed production
    • More uniform and earlier crop maturity
    • Increased nitrogen N-fixing capacity of legumes
    • Improvements in crop quality
    • Increased resistances to plant diseases
    • Supports development throughout entire life cycle

Sources of Runoff

  • Point source pollution: A collective term for contaminants which originate from a specific point, such as an outfall pipe. Point sources are generally regulated by an NPDES permit
  • Nonpoint source pollution: A collective term for contaminants which originate from diffuse sources, such as a farm field
  • Agriculture
    • Animal manure, excess fertilizer applied to crops and fields, and soil erosion
    • Fertilizers and animal manure, which are both rich in nitrogen and phosphorus, are the primary sources of nutrient pollution from agricultural sources.
  • Stormwater
    • Precipitation that falls in cities and towns. Runs across sidewalks, and roads and picks up pollutants before entering local waterways
    • Storm flow/storm water: The fraction of discharge (flow) in a river which arrived as surface runoff directly caused by a precipitation event (rain). Storm water generally refers to runoff which is routed through some artificial channel or structure, often in urban areas.
  • Wastewater
    • Our sewer and septic systems are responsible for treating large quantities of waste, and these systems do not always remove enough nitrogen and phosphorus before discharging into waterways.
  • Fossil Fuels
    • Electric power generation, industry, and transportation using fossil fuels
  • In and Around the Home
    • Fertilizers for yards, yard and pet waste, and certain soaps and detergents containing nitrogen and phosphorus
    • The amount of hard surfaces and type of landscaping can also increase the runoff of nitrogen and phosphorous during wet weather

Activity: Investigation Creation

Based off the information from this lesson and previous lessons learned, have students research and investigate solutions to reduce runoff. Students can research current and previous runoff management solutions and then will use the information they have researched to revise or create their own solution to runoff. Students to research their planned proposal and then draw or construct their idea to then present to the class.

  • Think about how humans, plants, animals and other organisms still need to use water.
  • How does surface water differ in different ecosystems?
  • One goal is to increase crop yield. How could minimizing surface runoff help increase crop yield?
  • What would the potential cost be of implementing your solution?
  • What criteria did you use to develop your plan?
  • What trade-offs will there be?
  • Consider: safety, reliability, and aesthetics for your solution.

Ways to Reduce Nutrient Pollution Through Agriculture

  • Best management practice (BMP): a general term for any structural or upland soil or water conservation or crop production/land use practice. Examples of conservation practices and structures include terraces, grass waterways, sediment retention ponds, reduced tillage systems, etc. For crop production, BMPs could include fertilizer form, application rates, timing and method, adjusted for crop needs and soil test levels.
  • Watershed efforts: The collaboration of a wide range of people and organizations often across an entire watershed is vital to reducing nutrient pollution.
  • Nutrient Management: Applying fertilizers in the proper amount, at the right time of year and with the right method.
  • Cover Crops: Planting certain grasses, grains or clovers can help keep nutrients out of the water by recycling excess nitrogen and reducing soil erosion.
  • Buffers: Planting trees, shrubs and grass around fields, especially those that border water bodies, can help absorb or filter out nutrients before they reach a water body.
  • Conservation Tillage: Limited amount of tillage. Reducing how often fields are tilled reduces erosion and soil compaction, builds soil organic matter, and reduces runoff.
  • Managing livestock waste: Keeping animals and their waste out of streams, rivers, and lakes keeps nitrogen and phosphorous out of the water and restores stream banks.
  • Drainage water management: Reducing nutrient loadings that drain from agricultural fields helps prevent degradation of the water in local streams and lakes.
  • Edge of field (water) monitoring: collection of water samples either from surface runoff or subsurface flow (tile flow), typically used to track performance of a best management practice

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

Did you know? (Ag facts)

  • Healthy plants often contain 3-4% nitrogen in their above-ground tissues.
  • Next to calcium, phosphorus is the most abundant mineral in the body.
  • More than 100,000 miles of rivers and streams, close to 2.5 million acres of lakes, reservoirs and ponds, and more than 800 square miles of bays and estuaries in the United States have poor water quality because of nitrogen and phosphorus pollution.

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

  • Water Footprint Activity: Students can track the amount of water they use on a daily basis and estimate the amount that contributes to runoff. They can then create a solution that decreases their own water footprint.
  • Using a Stream Table, have students create a concept that directs the flow of water in a direction to be filtered or away from a major body of water. Test their concept on the stream table using trial and error testing.
  • Write a proposal to their legislator that presents a solution to a specific kind of runoff.

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) (your name)

Hannah Pagel

Organization Affiliation (your organization)

Iowa Agriculture Literacy Foundation

National Agriculture Literacy Outcomes

  • T4.9-12.d. Evaluate the benefits and concerns related to the application of technology to agricultural systems (e.g., biotechnology)
  • T4.9-12.c. Discuss population growth and the benefits and concerns related to science and technologies applied in agriculture to increase yields and maintain sustainability
  • T1.9-12.a. Describe how wildlife habitats are created and maintained by farmers/ranchers and why these habitats are important (e.g., promoting pollinator habitat, insect refuges, creating buffer zones for nutrient management, etc.)

Iowa Core Standards

  • HS-LS2-6. Evaluate the claims, evidence, and reasoning that the complex interactions in ecosystems maintain relatively consistent numbers and types of organisms in stable conditions, but changing conditions may result in a new ecosystem. (soil structure, water cycle, nitrogen cycle)
  • HS-LS4-5. Evaluate the evidence supporting claims that changes in environmental conditions may result in: (1) increases in the number of individuals of some species, (2) the emergence of new species over time, and (3) the extinction of other species. (increased nutrients like fertilizers can lead to increased yields)
  • HS-ESS3-2. Evaluate competing design solutions for developing, managing, and utilizing energy and mineral resources based on cost-benefit ratios. * (adding nitrogen vs. crop rotation)
  • HS-ETS1-3. Evaluate a solution to a complex real-world problem based on prioritized criteria and trade-offs that account for a range of constraints, including cost, safety, reliability, and aesthetics, as well as possible social, cultural, and environmental impacts. (watersheds prioritization activity

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