Nitrogen Cycle Investigation



Class Periods




Subject Areas



Students read Your Chicken Nuggets Are Killing Your Crab Cakes,” an article about the connections between agriculture and nitrogen pollution in waterways.  Students map the movement of nitrogen across the United States via the food system, and discuss how (or whether) the nitrogen map would change if people stopped eating chicken nuggets.


  • Identify major sources of nutrient pollution of estuaries.

  • Translate textual information into map-based representations.

  • Speculate about a hypothetical case.

Instruction Plan


  1. Project Map of continental USA with Major Rivers and Mountains, No Labels (slide #1 of Maps to Explore Nitrogen Pollution- Teacher Powerpoint.)

  2. Ask your students: “What can you identify on this map?  Are you familiar with any of the mountains or rivers?”

  3. Point to a few rivers and ask, “Which way does this river flow?  How can you tell?”


  1. Students read Your Chicken Nuggets Are Killing Your Crab Cakes.”

  2. As they read, students identify locations from the article on “Continental United States with States, Capital Cities, and Rivers” (map #1 in Maps to Explore Nitrogen Pollution- Student PDF).


  1. Students examine the maps in Maps to Explore Nitrogen Pollution- Student PDF.  

  2. In small groups, students use information from the article and maps to annotate the map “Continental United States with States, Capital Cities, and Rivers” with arrows to indicate the movement of nitrogen across the US.

    • Students decide where to draw arrows on the map to show the movement of nitrogen from one place to another.  The direction of each arrow should show one route by which nitrogen moves around the country, according to the article.

    • Groups label each arrow in the article according to how the nutrients move along that route.  Here’s an example of one of these labeled arrows:


Students add the following arrows to their maps:

  • Show the nutrients that are shipped to New York City in the form of chicken nuggets.

  • Show what happens to those nutrients after New Yorkers eat the chicken nuggets.

    • At this stage, you could introduce a more zoomed-in map of New York City, such as one you can find on Google Maps.


Ask your students: “How does the nutrient map change if people stop eating chicken nuggets?  Does it necessarily change at all?”

(This could potentially be a long and rich discussion!)


Ideally students will raise a lot of questions about nitrogen and estuaries!  Depending on what kinds of questions they raise:

  • This could be a great time to provide the adapted article The Dark Side of Nitrogen, which focuses on the role of nitrogen in agriculture, the role of agriculture in nitrogen pollution, and the way that federal policies influence this situation.

  • This could be a perfect opportunity to make available the Nitrogen and Estuaries Topic Library. There students can do supported but independent research in search of answers to some of their questions.

  • This would also be a great time to dig more into the maps from the powerpoint Maps to Explore Nitrogen Pollution- Teacher Powerpoint.  Many of these maps come from Tom Philpott, the author of Your chicken nuggets are killing your crabcakes.  The powerpoint includes maps and text he put together for a related article: http://www.motherjones.com/tom-philpott/2013/08/gulf-of-mexico-dead-zone-growth


NGSS - Cross-Cutting Concepts

  • Energy and Matter

    • Matter is conserved because atoms are conserved in physical and chemical processes.

NGSS - Disciplinary Core Ideas

  • ESS2.A: Earth’s Materials and Systems

    • All Earth processes are the result of energy flowing and matter cycling within and among the planet’s systems. This energy is derived from the sun and Earth’s hot interior. The energy that flows and matter that cycles produce chemical and physical changes in Earth’s materials and living organisms.
  • LS2.B: Cycle of Matter and Energy Transfer in Ecosystems

    • Food webs are models that demonstrate how matter and energy is transferred between producers, consumers, and decomposers as the three groups interact within an ecosystem. Transfers of matter into and out of the physical environment occur at every level. Decomposers recycle nutrients from dead plant or animal matter back to the soil in terrestrial environments or to the water in aquatic environments. The atoms that make up the organisms in an ecosystem are cycled repeatedly between the living and nonliving parts of the ecosystem.

NYC Science Scope & Sequence - Units

  • Grade 6, Unit 4

    • Interdependence

NYS Science Standards - Major Understandings

    • Matter is transferred from one organism to another and between organisms and their physical environment. Water, nitrogen, carbon dioxide, and oxygen are examples of substances cycled between the living and nonliving environment.