Activities for Module II, Corn, Beans, and Burgers
Activities for Section C: Field Crops in the Agro-ecosystem
Agro-ecosystem Activity 1: Thinking about soils
Purpose: This activity is designed to get students observing and thinking about soil. Because soil is so complex and no two samples will be exactly alike, there are not “correct” outcomes.
Advance preparation : Collect
materials: clear plastic cups or clear plastic
bottles, soil-less planting medium. You can either
collect the three different soil samples in advance,
or have the students collect them. If the students
will collect them, you will need a shovel and
something to collect the soil in. This activity
requires observation over a period of weeks.
Instructors may wish to have students begin the
activity two or more weeks before beginning
this “Corn, Bean, and Burgers” module.
Estimated time: 15 minutes
to one hour the first day; 3 to 5 minutes a day
for two weeks.
Each student or small group of students will observe plants growing in three different types of soils. Suggested types for comparison are:
- Soil from a conventional crop field
- Good quality garden soil mixed half and half with mature compost
- Soilless planting medium such as sand, peatmoss, perlite, or vermiculite (may contain trace amounts of asbestos).
- Give each group three 10 or 12-oz clear plastic
cups or have them make three bottle biology
planters. Put drainage holes in bottom of each
planter and fill with one soil type to within
1 inch of top. Have each student/group fill
out worksheet describing each soil type. You
can have the soil already collected for the
class, or you can have the students collect
the different soil types themselves
Instructions
for making bottle biology planters.
- Plant rapid-growing seed(s) in each planter.
Suggested varieties: radishes, beans, annual
ryegrass. (Use same variety for all 3 soil types,
students may all plant same plants or may choose
different types.)
- Have students water seeds regularly and observe
growth over time.
- Discuss differences in growth among
different soil types. Discuss how soils outdoors
at field scale function differently than the
small samples in cups. Discuss management differences
(especially lack or cost of irrigation) and
implications for different soil types.
Worksheet for Soils Activity
(MS Word document)
Supplemental soil activities
There are excellent activities developed by the
Center
for Agroecology and Sustainable Food Systems at
the University of California that introduces
students to soil processes. These materials were
developed for college students, but demonstrations
1 (Organic Matter Decomposition, pp. 21-23) and
3 (Earthworm Populations, pp. 31-34) are suitable
for high school classes as well.
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Agro-ecosystem activity 2: Resource or Pollutant?
Purpose : Build understanding of agricultural pollution sources and the relationship between agricultural resources and pollutants.
Advance preparation : None
Estimated time: 10 minutes
- Have students brainstorm a list of agricultural pollutants. Ask them to consider whether any of them can also be considered as resources. Discuss what determines whether the chemical is a resource or a pollutant and how it could be kept in the “resource” category. Describe the source and the sink for each pollutant.
Examples:
- Nitrates and nitrites : key plant nutrients in the soil, pollutants in drinking water and surface water
- Phosphorus : key plant nutrient in the soil, pollutant in surface water
- Manure : beneficial soil amendment at moderate levels, pollutant in surface water and potential source of nitrates, phosphorus, and bacteria in surface and ground water
- Pesticides : can provide a convenient and economical way to manage pests, pollutants for non-target species from humans to beneficial insects, birds, fish, etc.
- Pollen : necessary for growth of crops, GM pollen is a pollutant for non-GM crops, especially organic crops; can also be a pollutant for people suffering allergies
- Soil and harvested crops : critical resources, but can produce dust and sediment, causing air and water pollution
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Agro-ecosystem activity 2-A: Pollutant or Resource?
- Have students read information on the use
of hazardous wastes in agricultural fertilizers
Nutrient
Management and Fertilizer
Western
Environmental Law Center's Latest News
Better
Rules for Zinc Fertilizer Recycling
For more in-depth background they can read “Fear
in the Fields”
- Ask students to list arguments for and against
regulating hazardous wastes in fertilizer. (Requiring
labeling is a kind of regulation.)
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Agro-ecosystem activity 3: Hypoxia Hearings Purpose: Students explore a real controversy about the impact and regulation of agricultural pollution to get an understanding of the different interests involved and the scientific uncertainties and political complexity of managing environmental problems.
Advance preparation: Either each group will need internet access, or the teacher will have to print out information for each group to use.
Estimated time: 1 to 2 hours
- Have students conduct a role playing exercise to explore the issues surrounding hypoxia in the Gulf of Mexico . Assign students the following roles:
- Congressional representatives
- Scientists from government agencies (National Marine Fisheries Service, US Dept. of Agriculture, US Geological Survey, etc.)
- Farmers or representatives of farmer organizations
- Environmental organization representative
- Representatives of commercial fishing organizations
- Industry representative(s)
- Municipal sewage treatment representative
The assignment for the class is to have the congressional representatives come up with a way to address the hypoxia problem (such as regulations on nitrogen discharges or fertilizer use, taxes on fertilizers, incentive or grant programs to support best management practices, more research and monitoring, or a combination of approaches).
- Give students 30 minutes to 1 hour to research and prepare their positions. Then hold the hearing for 30 to 45 minutes. If time allows, have the class discuss how the hearing went after the role-playing is done.
Assignments by role:
- Congressional representatives: propose actions to address hypoxia, question other spokespeople to determine if proposals will work. (The representatives do not have to agree with each other.) One representative will have to facilitate the hearing.
- Scientists from government agencies: Answer technical questions.
- All other stakeholder roles: Prepare statements for or against the proposal(s) and answer congressional questions.
For information on hypoxia see
US Geological Survey http://toxics.usgs.gov/hypoxia/hypoxic_zone.html
American
Farm Bureau
National
Oceanographic and Atmospheric Agency
The Sierra Club
Hypoxia
in the Northern Gulf of Mexico: An Update by the EPA Science Advisory Board ,
especially the Executive Summary (pages 33-36 and 39-41 of the pdf)
Agro-ecosystem activity 4: Diversity in natural habitats
Purpose: Students will get a sense of the biological diversity of natural habitats and compare it to the lack of above-ground diversity in most agricultural systems. Students will learn to identify some wild plants using field guides or keys.
Advance preparation: Get field
guides or botanical keys to help students identify
species they do not know. Locate a natural or
semi-natural area students can easily visit. The
area can be woodland or untended grassland on
or near school property, it does not have to be
a formal park or natural area. Check if it is
permitted for students to collect plant samples.
Print out species lists from one or more of the
websites listed below.
Estimated time: 10 minutes to 1 hour
- Have the class make a poster or list of plant
and/or wildlife species one might find in one
acre of prairie or woodland. If possible, have
students visit a natural area and identify as
many of the plant and animal species there as
possible. Have them count the number of species
they cannot identify. Contrast with species
one finds on one acre of cropland.
- Visit The
Wisconsin Botanical Information System and
The
University of Iowa Herbarium for sample
species lists for natural areas.
Other useful websites include: The
Warren County Conservation Board
The Tallgrass Prairie in Illinois
The
Iowa Prairie Network
The
University of Wisconsin Arboretum
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Agro-ecosystem
activity 5: is ethanol sustainable?
Purpose: Students explore the
arguments for and against ethanol production.
Students learn to get and evaluate information
from the internet.
Advance preparation: Part 1:
Print out and copy the biofuel
sustainability worksheet. Students must have
access to the web to do this activity. Part 2:
Print out the How
Much Corn Would it Take? worksheet and make
copies. Students need to be familiar with nutrient
flow and pollution issues in corn production before
they do this activity.
Estimated time: Part 1: 50 minutes
or more. Part 2: 10 minutes to read and complete
the worksheet, plus 10 to 20 minutes for optional
class discussion.
Part 1:
Have students do a web quest on ethanol production,
to answer the question of how well ethanol production
fits the 4 biofuel sustainability criteria developed
by Amory and Hunter Lovins and Marty Bender:
Suggested articles and websites include:
The Great
Lakes Bioenergy Research Center has a number
of excellent biofuels
educational resources, including an activity
that focuses on carbon balance of biofuels http://www.greatlakesbioenergy.org/wp-content/uploads/2009/03/better_fuel.pdf
Is
ethanol energy-efficient? from journeytoforever.org
provides a pro-ethanol overview of the ethanol
debate and links to other information sources.
Biofuels:
Environmental Consequences and Interactions with Changing Land Use provides
an overview of recent assessments of biofuels projects and impacts. The executive
summary is a good starting point.
ethanol.org is
one of the many ethanol industry websites
Ethanol's
Contrasting Carbon Footprints describes how
different assumptions and measures can lead to
very different conclusions and energy policies.
The article Ethanol:
A "Green" Alternative? from the University
of California Berkeley Research offers a
brief summary of the arguments of one of ethanol’s
biggest critics.
How
Biomass Energy Works, an article from Union
of Concerned Scientists provides a general
overview of biomass energy.
The
Hybrid Highway from the Institute
for Local Self-Reliance (ILSR) provides a
cautionary view on the efficiency and feasibility
of hydrogen fuels in the next 20 years. ILSR also
has articles on renewable energy sources.
Implications
of Increased Ethanol Production for U.S. Agriculture from
the Food
and Agricultural Policy Research Institute at
the University of Missouri discusses potential
economic impacts for farmers of increased ethanol
production.
Cleaner-Burning
Gasoline Without MTBE from the Department
of California Environmental Protection Agency
summarizes the role of ethanol in reducing air
and groundwater pollution from gasoline.
Effects of Increased Biofuels on the U.S. Economy in 2022 discusses the uncertainties and possible economic consequences of increased use of biofuels.
Students will also have to use their background
knowledge about corn production, as well as knowledge
gained from exploring the first three ecological
questions in this section of the curriculum.
Part 1: Biofuel sustainability worksheet
Key
Part 2:
Have students complete the How
Much Corn Would it Take? worksheet, either
on their own or in small groups.
Part 2: How
Much Corn Would it Take? worksheet
Key
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