Course title

Pre-requisite

Course description

Approximately how much time per week do students spend conducting hands-on laboratory experiments in this course?
The Ag Science I class at Peoria High School meets every other day for ninety (90) minutes for an entire year; which equates to around 135 hours (90 days times 1.5 hours = 135 hours). Approximately 90 hours of that time is spent doing hands-on work in the greenhouse; gardens; nursery or laboratory.

Briefly describe course content. Please include a list of the laboratory experiments or projects you do that require manipulation of equipment.
This course is designed to provide students with authentic hands-on learning experiences about the field of science through an agriculturally based system. Students spend more than half of their time (90 hours) working in the Department?s 3000 ft2 greenhouse; gardens; nursery; turf management lab; welding/mechanics shop; and biotechnology laboratory. Units and labs taught in the class include:

Orientation
Life Knowledge
Nourishing the Planet
Scientific thought/knowledge
FFA Information
FFA Creed
Atomic Structure
Inquiry
Essential Nutrients for plants
Soil Properties
Plant Anatomy
Plant-Soil Interactions
Nutrient Deficiencies
Fertilizer and Population
Sustainability
Supervised Agricultural Experience
FFA History
Pure/Applied Science
Active/Pass Transport
Garden Installation - Lab Extensions
Human Impact on Natural Environments
Opening Ceremonies
Recordkeeping
Garden Review
FFA Opportunities
Basic Drafting
Garden Design
Sprinklers & Irrigation
Hardscape & Irrigation Installation
Food Science & Garden Planting
Parliamentary Procedures
Bottle Biology
Feeding the Future
Nature of Science & Big Bang

Using standard Scientific Method outlined by the following questions; describe one typical laboratory assignment associated with this course.

State the problem or concept investigated during this laboratory assignment. (Do oranges stored in a refrigerator have more Vitamin C than oranges picked fresh from a tree?)
How do soil types differ with regard to air space; electronic charge; and water retention?

Formulate a hypothesis for this problem using ?if/then? statements. (If oranges picked fresh from a tree have more Vitamin C; then juice from these oranges will take longer to turn a starch solution blue.)
In this lesson the students conducted three independent yet related ?mini? labs. Their collective hypotheses are listed below.
Loamy soil will have a greater air space than native and sandy soil.
Sandy soil will have a more negative charge than native and loamy soil.
Water penetration will be greater in the sandy soil compared to native soil and loamy soil.

Describe the experiment you performed to prove or disprove your hypothesis. List all essential materials. Describe each step you performed in the experiment.
Soil and Air Space
1. Clear test tubes should be filled with an even amount of the three soil types.
2. Add 20 mL of each soil type to their own tube. Tamp each tube to allow the soil to settle.
3. Add 20 ml of water quickly then observe tube carefully.
4. Record the final volume that the water level is at. The amount less than 40 ml indicates how much air space was in the soil.
Soil and Charge
1. Prepare 2 soil columns for each soil sample using 12 oz. water bottles; cheesecloth; and rubber band.
2. Sample soil is placed inside each inverted column.
3. Positively charged (methylene blue) and negatively charged (bromothymol blue) dyes are added to each column.
4. Drained water is collected at the bottom of the funnel and water color (dye) is compared to original dye mixture.
Soil and Water
1. Place 120 mL of individual soil samples in large; transparent cylinders.
2. Tamp cylinders to settle soil.
3. Slowly add 80 mL of water to the soil samples.
4. Time how long it takes for the water to reach the bottom of the container.
5. Observe their behavior and record any results.

Describe the results of your experiment or study. Use graphs and charts where appropriate.
The data below represents findings from one class during the fall semester 2008. The numbers and observations were ?averaged? among the various group observations.

Soil and Air Space
Loamy Sandy Native
Volume of Air (mL) 12 5 8
Observations Many bubbles Few; tiny bubbles Some bubbles
Table 1: This table shows how much the initial water level ?sank? into the soil; thus revealing the amount of air space. Students also observed many bubbles coming up from the soil as the air was pushed out. The Loamy soil had the greatest amount of air space; followed by the Native soil and then the Sandy soil.

Soil and Charge
Loamy Sandy Native
Pos (+) Dye absorbed slightly Dye absorbed entirely Dye absorbed moderately
Neg (-) Dye passed entirely Dye passed entirely Dye passed entirely
Table 2: As the dyes proceeded through the soil some was absorbed and the rest passed through. The table shows the students? observations as to the amount of dye that was either absorbed or passed through. Amounts of dye were measured by visual comparison. All three soils appear to be negatively charged as they absorb the positive dye and none seem to absorb the negative dye.

Soil and Water
Loamy Sandy Native
Time (sec) 22 136 55
Observations Even settling throughout Seeps very slowly Went sporadically
Table 3: The Loamy soil allowed the water to move through it more rapidly; while the tighter spaces in the Sandy soil slowed the water?s progress.

Explain your data or results. Give an analysis of your experiment.
Soil and Air Space
The three soil types all maintained some air space. From this lab it appears that the Loamy Soil had the most space within it. There was more space in the Native soil than the Sandy soil. In addition to more space the space seems ?looser? as the bubbles were larger in the Loamy and Native soils than the Sandy soil.

Soil and Charge
Since none of the negatively charged dye was absorbed; but most of the positively charged dye was absorbed we can assume that the soil itself is negatively charged. We also noticed that the sandy soil seemed to absorb more of the positive dye suggesting that its charge was greater.

Soil and Water
The water penetrated the Loamy soil to the bottom of the container the quickest; followed by the Native soil and then the Sandy soil. The Native soil seemed to go in spits-and-starts following fracture lines between different sized particles. The Sandy soil was even though very slow.

Write a conclusion for your study. Was your hypothesis supported or refuted?
Hypothesis 1: Loamy soil will have a greater air space than native and sandy soil.
The first hypothesis was supported. The large ?fluffy? particles provide a great deal of space for air. The uniform size of the sand particles allows them to pack more closely together and thus have less air space. The volume of air and the rapid pass through rate in loamy soil support the conclusion that that there is greater air space in loamy soils.

Hypothesis 2: Sandy soil will have a more negative charge than native and loamy soil.
This was also supported. While all of the soil types had a negative charge; the sandy soil seemed to attract the most of the negative dye.

Hypothesis 3: Water penetration will be greater in the sandy soil compared to native soil and loamy soil.
Our initial hypothesis was incorrect: the sandy soil was much slower with regards to water penetration. This seems counter intuitive from the stand-point that water and sand seem to always go together. Sand is also used in the landscape industry as a ?drainage? material.

This lab allows the students to investigate an important component of plant science; soil. They will be able to apply these principles of soil to their future studies of plants.

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Approved

Approved competency code

• LINT
• Integrated science

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Online / Virtual