What do Plants Need to Grow?

What do Plants Need to Grow?

Target Grade Level / Age Range

2nd Grade

Time 

Initial lesson 45 minutes, follow up lessons needed to record observations and present research findings

Purpose

By the end of this lesson students will:

  1. understand that plants in agriculture need natural resources, such as sunlight and water, in order to grow. 

Materials

  • Plants on a Farm by Nancy Dickmann
    • Available in IALF’s Lending Library
  • Light by Daniel Nunn
  • Water by Daniel Nunn
  • 4 pots
  • Soil
  • Soybean seeds
  • Water
  • Label for each pot (1. Sunlight and No Water, 2. Water and No Sunlight, 3. Sunlight and Water, 4. No Sunlight and No Water)
  • Student Worksheet
  • Final Observation Worksheet

Suggested Companion Resources (books and websites)

  • From Seed to Plant by Gail Gibbons

Vocabulary

  • Natural resource – something that is found in nature and useful to humans (for example, sunlight, soil, water, air, trees, minerals).
  • Germination – development from a seed to a plant.
  • Photosynthesis – the process by which plants make food.

Background – Agricultural Connections

  • Plants on farms, such as corn and soybeans, need natural resources to live (sunlight and water).
    • Plants also need soil to obtain the nutrients they need to grow after germination.
    • Seeds have the ability to germinate with just heat and water, but the plants will quickly die if they don’t get more nutrients from an outside source (such as soil).
    • Different plants will need different amounts of sunlight and water (think cattails versus cacti), but these things are important in plant development.
  • Plant leaves capture sunlight to make food, or energy, to grow.
    • Photosynthesis requires sunlight. The chloroplasts within the plant cell will use the sunlight to create the sugars needed for growth. More information on photosynthesis can be found here: http://photosynthesiseducation.com/.
    • Plants also need air to photosynthesize.
  • Plants drink water, just like people. Plant roots absorb water from the soil.
    • Plants can have too much water, as well. If the soil is too waterlogged, the plant doesn’t grow well.

Interest Approach or Motivator

  • Tell students you wanted to plant a soybean plant. Ask them what you would need to do that. Would you need air? A lamp? Brainstorm some things plants need.

Procedures

  1. To open the lesson and get students thinking about plants, read Plants on a Farm by Nancy Dickmann. Discuss why plants on a farm are essential in our lives. 
  2. After reading, use a word web on the whiteboard to brainstorm with students what plants need to grow.
    1. Write “What plants need to grow” in the middle circle. As students suggest different things that plants need, put those in bubbles shooting off of the middle circle.
  3. Read Light by Daniel Nunn.
    1. If this book is not available, talk with students about what would happen if plants tried to grow in the dark. Would they survive? Why or why not?
  4. After reading, ask students to Turn and Talk to their neighbors about why plants need light.
    1. Have a few groups share with the class what they discussed with their partner.
    2. Ask students to put a thumb up or down to show if they think plants need light to grow.
  5. Going back to the word web on the board, either circle light or add it to the word web. 
  6. Read Water by Daniel Nunn.
    1. If this book is not available, talk with students about if plants need water or not. Does it depend on the plant? What would happen if you tried to grow plants without water?
  7. After reading, ask students to Turn and Talk about why plants need water.
    1. Have a few groups share with the class what they discussed with their partner.
    2. Ask students to put a thumb up or down to show if they think plants need water to grow.
  8. Going back to the word web on the board, either circle water or add it to the word web.
  9. Ask students to Lean and Whisper what two things plants need to live and grow. 
  10. Have all students share with the class what they whispered to their partner. 
  11. Ask this question, “What do you think would happen if plants on a farm didn’t get water or light? How would this affect the world or your life?”
    1. Would your fruits and vegetables grow without water and sunlight? What about the corn and soybeans that feed animals? Would you be able to have cheeseburgers and chicken nuggets if plants didn’t have water and light?
  12. Explain to students that they are going to design an experiment to explain what plants need to grow. Tell them they will be using soybeans in this experiment. Soybeans are a common crop in Iowa.
  13. Divide students into four groups and assign each group a label that shows what their plant will or will not receive (Pot 1. Sunlight and No Water, Pot 2. Water and No Sunlight, Pot 3. Sunlight and Water, Pot 4. No Sunlight and No Water).
    1. Ask students what is common between all four pots. The answer should be soil. Explain that plants get the nutrients they need from soil.
    2. Model for students how to plant a soybean seed in their pot.
  14. Allow students to plant their seed and put their label on the pot. 
    1. Place Pot 1 in a sunny spot in the classroom but do not water during the experiment. 
    2. Water Pot 2 but place it in a cupboard or locker where it will not get sunlight.
    3. Water Pot 3 and place it in a sunny area in the classroom. 
    4. Place Pot 4 in a cupboard or locker with no water and no sunlight. 
  15. For each pot, ask students to Turn and Talk with their partner what they predict will happen to their soybean plant. 
  16. Have a few groups share with the class what they discussed with their partner. 
  17. Hand out the student worksheets to the class. Have students record what the plants look like on their recording sheet (students can write or draw their observations). Explain to the students that they will be recording the state of the plants every other day in their Plant Growing Experiment Worksheet.
  18. It will be necessary to follow up for a few minutes every other day until their worksheet is filled. Have the students in groups 2 and 3 water their pots at the same time as students make observations.
  19. Once the experiment is over, have students write about what happened to each plant in each pot and what they learned about what plants need to grow (students can use results sheet if needed). They will record this on the Final Observation Worksheet. Have students share with a partner what they learned. Have some students share with the class what they learned.    

Essential Files (maps, charts, pictures, or documents)

Did You Know? (Ag facts)

  • Iowa is number one in the production of corn, soybeans, hogs, and eggs. Iowa’s agricultural products are essential to feed a growing world population. 
  • Nearly everything we eat, wear, and use comes from plants and animals grown on farms. 
  • Soybeans are a very versatile crop, and can be used for animal feed, soy biodiesel, foam in car seats, vegetable oil, and many other things!

Extension Activities

  • Give each student a leftover seed to grow at home.
  • Give students ideas for other experiments they can do at home to determine what plants need to grow. For example, do plants grow better in sand or soil? Do plants grow better when they have space and plenty of air or when they are in a tight space with little air?
  • Suggest students research how climate and geography affect how plants grow in Iowa.

Sources/Credits

Author(s)

Maggie Riggs

Organization Affiliation

Oskaloosa Elementary School

National Agriculture Literacy Outcomes

  • Plants and Animals for Food, Fiber & Energy:
    • T2.K-2 e. Identify the importance of natural resources (e.g., sun, soil, water, minerals) in farming.

Iowa Core Standards

  • Science:
    • 2-LS2-1. Plan and conduct an investigation to determine if plants need sunlight and water to grow. 
  • Language Arts:
    • W.K.7 Participate in shared research and writing projects (e.g., record science observations).