National Agricultural Literacy Curriculum Matrix
Agricultural Land Use
9 - 12
Three 60-minute activities
Students explore the impact of fertilizer on algae growth, soil erosion, and agricultural soil and water conservation practices.
- Algae Experiment Planning Sheet
- Algal culture, such as Oscillatoria, Chlorella, or mixed algae, 2 ML per student group
- Distilled Water
- Liquid Plant Fertilizer
- Masking tape and markers
- Transfer pipettes
- Test Tubes and a test tube rack, enough for groups of students
- Plastic wrap (for the tops of the test tubes)
- Land Management Presentation
- Projection equipment
- Three plastic 1L or 2L soda bottles, cut in half length-wise, empty and clean
- Additional leaf and forage material for creating natural soil conditions
- A chunk of sod, sized to fit within the plastic bottle demonstration area
- Clear plastic cups or glass beakers to measure water runoff
- Water, at least 100 mL
- Conservation Practice Research Guide
- Internet access for each student, or group of students
- Land Management Plan worksheet
- Internet access for each student, or group of students
Essential Files (maps, charts, pictures, or documents)
- Agricultural Land Use Presentation
- Algae Experiment Planning Sheet
- Conservation Practice Research Guide
- Land Management Plan
algal bloom: a rapid increase in the population of algae in a given area of water, which often causes the water to look green
erosion: the process of removing topsoil from one area and depositing it in another through the action of wind or water
fertilizer: material added to soil to increase soil fertility and crop yield; can be organic (such as manure or compost) or inorganic
plowing: the act of turning over the top layer of soil to prepare for planting which brings nutrients to the soil surface and buries old plant litter; performed with a tractor and plow
tilling: preparing soil for planting by breaking up clumps of soil to provide an even bed for seeds; performed with a tractor and tilling implement
topsoil: the top layer of soil, where most nutrients are available for plants
Background Agricultural Connections
Interest Approach – Engagement
- Find historical photos or videos from the Dust Bowl. Introduce them to this disaster in our nation's history.
- Prompt students to share their thoughts about the impact that these events had on our natural resources, specifically soil and water. Facilitate a discussion that leads students to discuss their thoughts about how farmers can negatively and positively impact the quality of these resources.
- Summarize the discussion and introduce the lesson informing students they will be learning about conservation practices used in agriculture to preserve the soil and allow farmers to continue to provide our food and fiber for years to come.
Activity 1: How does fertilizer affect algae growth?
Teacher Note: Four days before you plan to teach the lesson, have students set up algal cultures. They will plan and conduct a simple experiment to test the effect of fertilizer on algae growth using the Algae Experimental Planning Sheet.
- Ask students if they have heard of fertilizer and why it is used. They may be familiar with lawn or agricultural fertilizer and may answer that it helps plants grow.
- Pass out the Algae Experimental Planning Sheet. Have each lab group predict what the effect of fertilizer will be, and sketch out a basic experimental procedure (students should not worry about amounts of algae at this point). After students have planned their experiments, review the following procedure to make sure all students have set up an appropriate experiment.
- Obtain two test tubes. Label one “Control” and one “Fertilizer.”
- Use a clean transfer pipette to add 20 drops of algal culture to each test tube.
- Add 4 drops of fertilizer to the “Fertilizer” tube.
- Cover the tubes with plastic wrap. Poke holes in the plastic to allow for air exchange.
- Place the beakers in a sunny window or under fluorescent light for 4 days. Have students record their observations each day.
- Discuss the results of the algae experiment as a class. Students should notice that the test tubes containing fertilizer were greener than the control tubes, indicating faster algae growth with fertilizer. Ask students to share why they think this is. Students should come away with an understanding that the fertilizer contains nutrients (N, P, K) that enable the algae to grow faster.
Activity 2: What are the environmental impacts of agriculture?
Before you begin this activity, set up the erosion demonstration (see Step 3).
- Ask students to brainstorm ways that agriculture impacts the environment. Possible ideas include:
- natural resources (soil, water, air quality)
- animal habitat
- conserve land
- energy/fossil fuel use
- Show the image of the tractors plowing and tilling (Slide #1 in Land Management Presentation). Explain that plowing turns over the first layer of soil (about 12 inches) and that tilling further breaks up the soil to make an even surface for planting.
- Ask students what effect they believe plowing and tilling has on erosion, the removal of soil by wind or water. Demonstrate erosion in three different conditions: bare soil, soil with some cover, and soil with plants in it.
- Collect three plastic bottles of equal size (1-L or 2-L). Lay the bottles flat and cut an oval shape around the top to create a “boat.” Make sure that the sides of your boat are higher than the mouth of the bottle.
- Fill two of the bottles with soil. Cover the soil in one of these bottles with leaf and plant matter. Place the sod in the third bottle.
- Set up the three bottles so students can see them. Elevate the far ends of the bottles so that water will drain out of them. Place a clear cup or beaker beneath the mouth of each bottle.
- Ask students to predict which soil sample will have the most erosion, or the most sediment in the runoff.
- Pour an equal amount of water (~100 mL) onto the soil or plant matter in each bottle “boat” and evaluate the results by looking at the color of the runoff.Show the image of soil layers (Slide #2 in Land Management Presentation). The top layer is called topsoil, and it is where the nutrients and water that plants need to grow are stored. Topsoil is formed over hundreds of years by the breaking down of rock or soil parent material, and therefore cannot easily be replaced when it is eroded.
- Ask students, “What is fertilizer and why is it used?” Explain that farmers use fertilizers to increase the nitrogen, phosphorous, and potassium available to their plants. (Slide #3 in Land Management Presentation). Refer back to the results of the algae experiment in Activity 1.
- Ask students how fertilizer use by farmers and homeowners could cause more algae to grow in lakes and rivers. Show the image of the largest sources of nitrogen to streams (Slide #4 in Land Management Presentation). Ask students to identify the Mississippi river and tributaries. Point out the cropland and manure as sources of nitrogen and that the Midwest contributes the most, as shown in dark blue (Slide #5 in Land Management Presentation).
- Show the image of the algae bloom (Slide #5 in Land Management Presentation). Ask students how the excess algae affect the aquatic ecosystem. Students may believe that the excess algae provide more food for other marine organisms. However, when the algae die, they are decomposed at the bottom of the ocean or lake. Decomposers use up the dissolved oxygen, resulting in a hypoxic zone. The salt and temperature gradient prevents surface oxygenated water from mixing with the hypoxic water. While older fish can usually swim to safer waters, young fish, shellfish, mussels, and crabs may be killed due to lack of oxygen.
Activity 3: How do farmers reduce the environmental impacts of agriculture?
- Divide students into groups and assign each group one of the following conservation practices:
- Crop rotation
- Filter strip
- Cover cropping
- Contour farming
- Conservation tillage
- Habitat preservation
- Any other conservation techniques that interest students
- Have student groups research their conservation practice to answer the questions on the Conservation Practice Research Guide. The USDA Natural Resources Conservation Service Conservation Practices website is a good resource.
- Have students develop a poster to illustrate the practice and how it benefits the environment and share this information with the class. As each group presents their poster, the rest of the class should take notes on the major environmental benefits and uses of each conservation practice for use in Activity 4.
Activity 4: What is your land management plan?
- Have students apply the information they learned from the class presentations to a new situation. Students will imagine that they have inherited a parcel of farmland in Minnesota (or your local area, if outside of this particular state).
- Ask students what kind of information they would like to know about their new land. The Land Management Plan sheet gives information about the new farmland, including a map of the land and existing structures. Based on this information, students will each suggest at least two conservation practices they would choose to employ on their new farm. Students must justify their choices by writing a paragraph, stating how they expect each practice to benefit the farm and the environment, and indicate on the map the area where they would use each practice.
Concept Elaboration and Evaluation
After conducting these activities, review and summarize the following key concepts:
- The agriculture industry uses and maintains natural resources such as soil and water in order to grow and produce crops and animals that provide our food, fiber, and fuel.
- There are many examples of conservation practices designed to decrease soil erosion, maintain water quality, and preserve soil quality.
- Using sound and sustainable farming practices is important to preserve our ability to provide food for a growing population and to decrease the chance of another disaster like the Dust Bowl.
We welcome your feedback! Please take a minute to tell us how to make this lesson better or to give us a few gold stars!
In the algae bloom experiment, students could test different amounts or types of fertilizer, or use pond water from a local source in place of algal culture
Suggested Companion Resources
- Nutrients for Life eLessons (Activity)
- Planet Zorcon (Kit)
- How America Uses Its Land (Poster, Map, Infographic)
- Renewable vs Nonrenewable vs Inexhaustible Resources e-magazine (Booklets & Readers)
- How a New Evolutionary Map Could Help Farmers Eliminate Fertilizer (Website)
- Soil Health Education Resources (Website)
Agricultural Literacy Outcomes
Agriculture and the Environment
- Describe resource and conservation management practices used in agricultural systems (e.g., riparian management, rotational grazing, no till farming, crop and variety selection, wildlife management, timber harvesting techniques) (T1.9-12.b)
Science, Technology, Engineering & Math
- Describe how agricultural practices have contributed to changes in societies and environments over time (T4.9-12.b)
- Discuss population growth and the benefits and concerns related to science and technologies applied in agriculture to increase yields and maintain sustainability (T4.9-12.c)
Education Content Standards
Agriculture, Food, and Natural Resources Cluster Skills
CS.01.01Research, examine and discuss issues and trends that impact AFNR systems on local, state, national, and global levels.
CS.01.02Examine technologies and analyze their impact on AFNR systems.
CS.03.01Identify and explain the implications of required regulations to maintain and improve safety, health and environmental management systems.
CS.03.02Develop and implement a plan to maintain and improve health, safety and environmental compliance and performance.
CS.04.01Identify and implement practices to steward natural resources in different AFNR systems.
NCSS 3: People, Places, and Environments
Objective 4The causes and impact of resource management, as reflected in land use, settlement patterns, and ecosystem changes.
NCSS 8: Science, Technology, and Society
Objective 2Science and technology have had both positive and negative impacts upon individuals, societies, and the environment in the past and present.
HS-ESS3: Earth and Human Activity
HS-ESS3-4Evaluate or refine a technological solution that reduces impacts of human activities on natural systems.
HS-LS2 Ecosystems: Interactions, Energy, and Dynamics
HS-LS2-7Design, evaluate, and refine a solution for reducing the impacts of human activities on the environment and biodiversity.
Common Core Connections
Reading: Anchor Standards
CCSS.ELA-LITERACY.CCRA.R.10Read and comprehend complex literary and informational texts independently and proficiently.
CCSS.ELA-LITERACY.CCRA.R.7Integrate and evaluate content presented in diverse media and formats, including visually and quantitatively, as well as in words.
Speaking and Listening: Anchor Standards
CCSS.ELA-LITERACY.CCRA.SL.1Prepare for and participate effectively in a range of conversations and collaborations with diverse partners, building on others’ ideas and expressing their own clearly and persuasively.
Mathematics: Practice Standards
CCSS.MATH.PRACTICE.MP3Construct viable arguments and critique the reasoning of others. Students understand and use stated assumptions, definitions, and previously established results in constructing arguments. They make conjectures and build a logical progression of statements to explore the truth of their conjectures. They are able to analyze situations by breaking them into cases, and can recognize and use counterexamples. They justify their conclusions, communicate them to others, and respond to the arguments of others. They reason inductively about data, making plausible arguments that take into account the context from which the data arose. Students are also able to compare the effectiveness of two plausible arguments, distinguish correct logic or reasoning from that which is flawed, and—if there is a flaw in an argument—explain what it is.