Let’s Get Dirty

2nd Grade Science, Unit 2: “Plant Life”

GOAL: The students should gain and understanding that soil is not necessarily a basic need of plants and that plants can survive in many situations without soil.

Big Ideas:

·  Plants have basic needs in order to grow.

·  Plant structures have specific functions.

·  When a plant has all of its basic needs, photosynthesis occurs.

Specific Objectives:

1.  DESIGN an experiment that tests various growing substrates.

2.  INFER which substrates would help a plant grow and how the environment it is grown in affects its growth.

3.  RECORD data following the experiment.

GLCE Alignment:

L.OL.02.14 Identify the needs of plants.

S.IP.02.11 Make purposeful observations of plant growth that include the needs of plants and the plant life cycle.

S.IP.02.12 Generate questions based on observations of plant growth and plant parts.

S.IP.02.13 Plan and conduct simple investigations into plant growth and survival to determine the needs of plants.

S.IA.02.12 Share ideas about the needs of plants and life cycle stages.

S.IA.02.13 Communicate and present findings about plant investigations and their need for air, water and light.

S.RS.02.15 Use evidence when communicating ideas about the needs of plants and the life cycle of plants.

Background:

Students should have a familiarity with the basic needs of plants (air, water, light). Students should also understand that a plant needs nutrients to flourish, and most often these nutrients are taken out of the soil it is growing in. However, plants do not need soil so long as they receive the necessary nutrients and its root system is kept moist.

Resources:

Disney Hydroponics video - http://www.youtube.com/watch?v=OaWDOJlkscM

Hydroponic Growing Kit for classroom - http://www.amazon.com/Hydrofarm-EMSYST-Emilys-Garden-System/dp/B000053F9E/ref=sr_1_1?s=home-garden&ie=UTF8&qid=1308756448&sr=1-1

Life in the Desert article - http://environment.nationalgeographic.com/environment/habitats/desert-profile/

Anticipatory Set

What would happen if you pulled a plant out of the ground? Does a plant need soil in order to survive? This project will give you a chance to test if soil is a basic need of plants and how a plant will grow in different planting materials, or none at all.

Materials

Vermiculite

Sand

Water

River Pebbles

Paper Towel

Fertilizer (liquid)

Lima bean seeds

Vocabulary

Needs of plants
Air
Water
Light
Plant
Size
Photosynthesis
Oxygen / Carbon Dioxide
Nutrients
Fertilizer
Nitrogen
Phosphorus
Potassium
Hydroponic
Desert
Arid

Procedure:

1.  Read the National Geographic article on deserts and discuss how various plants can grow in even harsh, arid settings that often do not include soil, but instead rock, sand, and gravel.

2.  Watch the video from Disney’s Epcot Resort that demonstrates how Hydroponic farming works as well as the ability of plants to grow in various materials.

3.  Set up the experiment by laying out river pebbles, vermiculite, sand, and paper towel. Ask the students which of these substrates will the lima bean seeds grow on? Do the seeds need anything else besides light and water that they may normally receive from the soil?

4.  Discuss nutrients found in soil, and how certain plants require more or less of these nutrients to flourish. Introduce potassium, phosphorus, and nitrogen and how these nutrients are commonly found in our environment, and farmers use these nutrients in fertilizers to help plants grow.

5.  Using the materials, fill plastic cups 1/3 full with each of the materials. Place a lima bean seed in each substrate and moisten each. Using the liquid fertilizer mixed in water, add fertilizer to each seed and place in a sunny location.

6.  Monitor growth of each seed and water regularly with fertilizer mixture over the course of two weeks.

7.  Discuss as the seeds begin to grow the difference in growth between substrates.

Analysis Questions and Conclusions:

1.  Which substrate did the lima beans grow best?

2.  What purpose did the water and fertilizer serve?

3.  Is it easier, the same, or more difficult to grow plants without soil?

Assessment Based on Objectives:

Students will fill out the written assessment referencing what was learned in the experiment.

Let’s Get Dirty – Assessment

Scoring Rubric

CRITERIA
3 / Correctly explains how a plant can grow and survive so long as the basic needs are met and proper nutrients are provided.
2 / Correctly explains how a plant can grow without soil and survive so long as the basic needs are met.
1 / Correctly explains how a plant can grow without soil, but does not discuss basic needs or nutrients.
0 / Student makes little or no effort to explain how the plants will grow.

Theodore and Trudy are hanging out in the school garden. Theodore pulls a plant out of the ground. Trudy tells him that he is killing the plants by pulling them out of the ground. Theodore tells Trudy that a plant can live without soil, but she doesn’t believe him and goes to tell the teacher that he is killing the school garden. Explain why Theodore is correct in that a plant can live without soil. Be sure to use what you learned in your science experiments in your answer.

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