National Agricultural Literacy Curriculum Matrix
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The Right Solution
6 - 8
In this lesson, students will understand concepts about solutes, solvents, and parts per millions they learn how fertilizer solution is properly calculated and applied.
For the teacher:
- Two, 250 ml beakers
- One roll of paper towels
- One box of food coloring (exclude yellow)
- Colored pencils or crayons
- Becker Bottle from Flynn Scientific
For each group:
- One white ice cube tray (or well reduction plate with 12 wells)
- One permanent marker
- One eye dropper
- One, 1 liter beaker
- Three small plastic cups
For each student:
- The Right Solution Lab worksheet
Essential Files (maps, charts, pictures, or documents)
solvent: a liquid in which substances (or solutes) are dissolved forming a solution
solute: the substance dissolved in a solvent to form a solution
parts per million (ppm): a unit of measurement commonly used to describe the nutrient concentration in fertilizer solutions; can also be used to analyze contaminants in food, groundwater, air, and more
nutrients: any element taken in by a plant that is essential to its growth
mixture: combination of two or more different substances that are not chemically bonded and can be a solid, liquid, or gas
dilution: the process of lowering the concentration of a solution by adding a solvent
solution: a type of homogeneous mixture in which the particles of one or more substances (the solute) are distributed uniformly throughout another substance (the solvent)
Background Agricultural Connections
Interest Approach – Engagement
- Ask the class if they have ever used a powdered concentrate to create a beverage such as hot chocolate or fruit punch. Explain that whether they realized it or not, they were creating a mixture. A mixture is a combination of two or more different substances, which are not chemically bonded, and can be a solid, liquid, or gas. Explain that there are two types of mixtures: homogeneous (also called solutions), which are uniform and particles are not typically seen, and heterogeneous mixtures, which are not uniform and the particles can be seen.
- As a demonstration, add two tablespoons of salt to a 250 ml beaker of water and stir. Explain that the mixture is a homogeneous solution, meaning that the molecules within the solution—in this case water and table salt—are evenly distributed and look the same throughout.
- In another beaker add two tablespoons of sand to 250 ml of water and stir. Have students compare and contrast the two mixtures. Ask student to describe the difference between the sand and water mixture and the salt and water mixture. Explain that the sand and water mixture is a heterogeneous mixture, meaning that the molecules will not be evenly distributed throughout the liquid.
- Explain that in agriculture, fertilizer solutions are one way that farmers supply their crops with essential plant nutrients. In science terms, the solute is the fertilizer added to the water. The water is the solvent, which does the dissolving. The solution, more or less, takes on the characteristics of the solvent. The concentration of a fertilizer solution is defined by the amount of fertilizer (solute) dissolved in water (solvent).
- Ask students to raise their hands if they’ve ever heard the term “one in a million.” Discuss what the term means and why people say it.
- Build on the classroom discussion by explaining how unique “one in a million” really is. Show students a “One in a Million” Becker Bottle (Flinn Scientific, Inc.) to illustrate the concept. This three liter bottle contains one million tiny colored spheres. Each colored sphere represents a different quantity, or concentration. The yellow spheres represent 100,000 in a million, the red spheres represent 10,000 in a million, the white spheres represent 1,000 in a million, the pink spheres represent 100 in a million, and the green spheres represent 10 in a million. The single black sphere in the bottle represents one in a million, or in scientific terms, one part per million. Explain that today the class is going to investigate the scientific concept of “parts per million”—a unit of measurement used to describe a very small amount of material.
- Explain that in the scientific community, parts per million is expressed as “ppm.” Parts per million is the unit of measurement commonly used to describe the nutrient concentration in a fertilizer solution. It can also be used to analyze contaminants in food, groundwater, air, and more.
- Introduce the lab by explaining that students will use a dilution activity to create and investigate solution concentrations. Review laboratory safety instructions. Distribute and review the The Right Solution lab worksheet. Divide the class into pairs or triads, and direct students to the necessary materials.
- After students complete the dilution lab activity and The Right Solution lab worksheet, use a classroom discussion to debrief their findings. Discussion points may include:
- Good fertilizer practices that match fertilizer inputs to crop nutrient requirements will achieve high-quality, economically sustainable yields that reduce negative environmental impacts. Arable land available for growing food will continue to diminish as population growth continues. Efficiently managing inputs, such as water and fertilizer, will be essential to feeding a growing population.
- Improperly applied fertilizer can lead to environmental problems. It is important for anyone who applies fertilizer to follow application instructions. Farmers and researchers are constantly testing and implementing new methods for high precision use of fertilizers.
- Fertilizer is expensive. It is in the farmer’s best interest to apply the correct amount of fertilizer, supplying the plants with only the nutrients they need.
Concept Elaboration and Evaluation:
After conducting these activities, review and summarize the following key points:
- Soil is a valuable and limited resource that is necessary for the proper growth of plants that provide our food and fiber.
- Farmers and ranchers use many methods to monitor and maintain soil nutrients.
- Fertilizers help plants grow to their greatest potential. They must be applied properly.
- Create a Venn diagram to capture the differences and similarities of homogeneous and heterogeneous mixtures.
- Use an overhead projector to demonstrate complex math problems.
One part per million is equivalent to one hole in 55,555 rounds of golf! Put a million into perspective by challenging students to use the factor-label method to convert one part per million (or one part per billion) to a number that is meaningful to them. Consider expressing the unit of measurement in seconds, miles, U.S. population, etc.
Have students write the ppm data from their chart in scientific notation. For example, 700 = 7 x 102 0.0055 = 5.5 × 10-³
Show students a two-minute video highlighting the career of a greenhouse manager. Visit www.youtube.com/utahagclassroom and select the video titled “Greenhouse Manager.”
Offer an incentive for students who locate (and show you) the black sphere in the Becker Bottle.
Review your city’s annual water quality report. All public water systems are required to sample their source water and treated water for the presence of biological, inorganic, organic, and radioactive constituents. This report typically uses parts per million and parts per billion to summarize constituent levels. Look up and define unknown terms and create a public service announcement that highlights key findings and provides recommendations for community members.
Suggested Companion Resources
- Home Composting - Turning Your Spoils to Soil (Multimedia)
- Phosphate Mining Video (Multimedia)
- Potash Mining Video (Multimedia)
- Science of Soil Digital Explorations (Multimedia)
- Soil Science Videos (Multimedia)
- Under Your Feet: Exploring Soil Science (Booklets & Readers)
- Dig In: Hands-On Soil Investigations (Teacher Reference)
- How a New Evolutionary Map Could Help Farmers Eliminate Fertilizer (Website)
- Soil Science Society of America (Website)
Agricultural Literacy Outcomes
Agriculture and the Environment
- Discover how natural resources are used and conserved in agriculture (e.g., soil conservation, water conservation, water quality, and air quality) (T1.6-8.c)
- Recognize the factors of an agricultural system which determine its sustainability (T1.6-8.h)
Education Content Standards
Plant Science Systems Career Pathway
PS.01.03Develop and implement a fertilization plan for specific plants or crops.
MS-LS1 From Molecules to Organisms: Structures and Processes
MS-LS1-5Construct a scientific explanation based on evidence for how environmental and genetic factors influence the growth of organisms.
MS-LS1-6Construct a scientific explanation based on evidence for the role of photosynthesis in the cycling of matter and flow of energy into and out of organisms.
Common Core Connections
Reading: Anchor Standards
CCSS.ELA-LITERACY.CCRA.R.3Analyze how and why individuals, events, or ideas develop and interact over the course of a text.
CCSS.ELA-LITERACY.CCRA.R.4Interpret words and phrases as they are used in a text, including determining technical, connotative, and figurative meanings, and analyze how specific word choices shape meaning or tone.
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.