Back to all Lessons

Explore Corn

Explore Corn

Grade Levels: Middle School,High School

Corn is a vital part of the Kansas economy and landscape. Understanding how corn is planted, grown, and harvested helps students comprehend the importance of this crop to the Midwest. As cities grow, many people move away from an agricultural understanding, even though it is essential to their lives. In this activity, students will get a background in the origins of corn, as well as the growth process for a single corn plant. Students will also get the chance to dissect a corn plant.

Student Links

Below are links students can use to complete the Corn Staging Student Worksheet

DEKALB ASGROW DELTAPINE Website K-State Department of Agronomy Website

Teaching the Lesson

Science

  • LS1-5: Construct a scientific explanation based on evidence for how environmental and genetic factors influence the growth of organisms.
  • LS 3-2: Develop and use a model to describe why asexual reproduction results in offspring with identical genetic information and sexual reproduction results in offspring with genetic variation.
  • ESS3-2: Evaluate competing design solutions for developing, managing, and utilizing energy and mineral resources based on cost-benefit ratios.

Language

  • RI.3.1: Ask and answer questions to demonstrate understanding of a text, referring explicitly to the text as the basis for the answers.
  • RI.3.7: Use information gained from illustrations (e.g., maps, photographs) and the words in a text to demonstrate understanding of the text (e.g., where, when, why, and how key events occur).
  • W.3.2: Write informative/explanatory texts to examine a topic and convey ideas and information clearly.
  • SL.3.1: Engage effectively in a range of collaborative discussions (one-on-one, in groups, and teacher-led) with diverse partners on Grade 3 topics and texts, building on others’ ideas and expressing their own clearly.
  • Students will understand and be able to identify corn in various stages of growth.
  • Students will identify different types of corn.
  • Students will understand how corn goes from the vegetative to reproductive stage.

Materials for Explore an Ear of Corn:

Materials for Leaf Collar Method:

  • Leaf Collar Method Student Worksheet
  • 5 knives (such as a box knife or razor blade)
  • 5 cutting boards
  • 5 ears of dried corn
  • 5 fully developed corn plants (grown in a greenhouse if not available from a field)
  • 5 electronic scales

Students will be using a cutting utensil with a sharp edge to cut the corn. Show proper handling of the cutting utensil.

Length of Time for Preparation: 30 min
Length of Time for Classroom Teaching: 1.5 hours

Preparation Procedure/Instructions:

Students will be doing three lessons, all centered around the background knowledge below. Complete this unit’s lessons in the following order:

  • Lesson 1: Explore Corn: Corn Staging
    • Researching corn growth stages and corn history
  • Lesson 2: Explore an Ear of Corn
    • Corn plant dissection
  • Lesson 3: Leaf Collar Method

Begin by using these classroom discussion questions to find out what students already know (or think they know) about corn and where it is grown. This discussion can be done with the entire class, small groups, or as “bellwork”.

  • Where is corn grown? Why is it grown there?
  • How is corn grown?
  • What are the stages of corn growth?
  • When can you harvest corn?
  • How many ears of corn are there on one stalk?
  • What types of corn are there?

Once the discussion is finished, hand each student the Student copies of Explore Corn Article , and read it. Encourage students to highlight important

portions they would like to explore more. By the end of the article, students should be able to answer the following:

  • What are three uses for corn?
  • Possible answers: human consumption, livestock feed, ethanol, nylon fibers, and plastics. Can use The Uses of Corn poster to help with discussion.
  • How long has corn been around?
  • Possible answers: 7,000 years from Central Mexico or sweet corn developed in 1700s.
  • How many kernels are on a corn ear? How many plants can grow on one acre?
  • Answers: 600 kernels on one ear and 22,000 to 35,000 plants per acre.
  • Teacher could have students summarize what they learned about the history and origin of corn.
  • Student could research the differences between corn, such as dent, sweet, flint/popcorn, and flour/soft.

Why is corn a valuable crop? How does corn grow, pollinate, and produce kernels? What farming techniques are important to increase corn yield?

Corn is a grass, native to the Americas. Evidence in central Mexico suggests corn was used there about 7,000 years ago. Various Native American tribes shared their knowledge of corn, also known as maize, with early European settlers, saving many from starvation. Early American colonists ground dried corn as meal for flour to use in porridge, cake, and bread. Sweet corn, served as “corn on the cob,” was not developed until the 1700s.

Along with wheat and rice, corn is one of the world’s major grain crops. It is the largest grain crop grown in the United States. About 9% of all the corn is used to produce food for humans: corn meal, cooking oils, margarine, corn syrups, and sweeteners (fructose). About 64% of all corn is used as feed for livestock. Corn is harvested for either grain or silage, with most of the grain going to dairies, animal feeding operations, and poultry operations. Corncobs have been used in the manufacturing of nylon fibers, as well as being a source for producing degradable plastics. Ethanol, made from corn, is a renewable fuel used in today’s cars.

Corn is pollinated by wind and is typically planted in 30-inch rows. A single seed, or kernel, of corn may produce a plant that yields more than 600 kernels of corn per ear. Approximately 22,000 to 35,000 individual plants may be grown on an acre of land. Hybrid corn is developed to produce from one to two ears per plant. More than 80 million acres of the heartland are planted in corn each year. That’s almost as big as 60 million football fields! After the corn is harvested, the farmer begins to prepare the soil for the next season by mixing in nutrients, such as potassium and phosphorus, with some form of tillage (breaking up soil) to incorporate them. In the spring, the farmer will do a light tillage pass to create smooth bedding for planting. When the ground temperature is ready (50°F and expected to rise), the farmer will plant the corn seeds. The farmer will then add fertilizer, two inches deep and two inches to the side of the kernels, to help the seeds get a healthy start. After the seed is planted, most farmers will spray a pre-emergent herbicide to prohibit weed growth. When seedlings emerge and grow, the farmer will inject the soil with some form of nitrogen fertilizer before the V8 (eighth leaf development) stage. This spring fertilizer will allow for the plant to “green-up” and establish good photosynthetic activity through harvest. The farmer will continue to scout the crop through maturity for any additional pests. The farmer will harvest the crop when it is ripe in the fall.

Procedure for Lesson:

  • Pass out a copy of the Corn Staging Student Worksheet.
    • Students will need internet access to visit the DuPont Pioneer websites. The websites will be used as a resource to complete the Corn Staging Student Worksheet.
    • Students will read about and explore the different stages of corn growth while completing the worksheet.
      Think of this as a pre-lab so students understand different stage of life of corn.

Preparation:

  • Students will break into five groups. Students should closely follow the instructions on the Explore an Ear of Corn Student Worksheet.
  • At the end of this activity, regrouping the class to review can be helpful.

Procedure for Lesson:

  1. Hand out an ear of corn and corn plant. Identify the following terms on the blank corn diagram on the Explore an Ear of Corn Student Worksheet: roots, stalk, ear, kernel, silks, tassels, husk, and shank.
    1. Use the following website to identify the parts of a corn plant: http://www.nebraskacorn.org/wp-content/uploads/2010/07/unit1_TeachersKey.pdf
  2. What growth stage is it in? V (vegetative), VT (tasseling), or R (reproductive)?
  3. If there are kernels on the cob, what reproductive stage is it in?
  4. Lift the bushel, how much does it weigh?
  5. Pop off kernels. How much does a kernel weigh?
  6. How many kernels are there in a bushel?

Questions?

  • What are some things that may have altered these ears (pests, drought, water)?
  • What stage are they in (vegetative or reproductive)? Can you go into more detail about the stage?
  • Explore your ear – how many rows, how many kernels per row, how many kernels per ear?

Preparation:

  • Students will break back out into five groups for the Leaf Collar Method activity.
  • Students will be working with cutting utensils for this portion. Have students closely follow the instructions on their Leaf Collar Method Student Worksheet.
  • Regroup the class at the end of this activity to talk through answers to questions.

Procedure for Lesson:

  • Hand out the Leaf Collar Method Student Worksheet. Have student follow the instructions on the sheet.
  • Use a knife and cutting board to carefully split the stalk of a corn plant in half, vertically, down to the roots.
  • Remembering that the first four nodes are often indistinguishable within the crown, count the number of nodes to determine the vegetative stage that the corn plant is in.
  • Compare the nodes counted within the stalk to the number of leaf collars found on the outside of the plant.

Reflection:

  1. Why is it necessary to split the stalk to accurately determine what vegetative stage the corn plant is in?
  2. How do the internal nodes compare to the external leaf collars found in/on the plant?
  3. How can determining the vegetative stage of the corn plant help the farmer determine when to input fertilizers and predict the ear length?

Students should be able to identify the nodes on the plant and be able to talk about what growing stage the plant is in. Use this to talk about the advantage of understanding what is needed to bring this plant to full growth and when we can apply different nutrients and pesticides/herbicides/fungicides.

Before leaving class, one way to evaluate content knowledge is to create an “Exit Ticket”. Students respond to these questions before leaving class (answers are listed in bullet points):

  • What are four major stages of growth for a corn plant?
    • VE, VT, R1, R3
  • What are the top two uses for corn?
    • Livestock feed and Ethanol
  • How long is it thought corn has been around?
    • 7,000 years
  • How many kernels are on a corn ear? How many plants can grow on one acre?
    • 600 kernels per ear, 22,000 to 35,000 plants per acre
  • What can the Leaf Collar Method tell us about a corn plant? What stage of life it is currently in?
    • answers vary depending on stage of corn plant
  • What are some things that can impact corn growth?
    • Pests, drought, water
  • Climatologist
  • Agronomist
  • Biologist
  • Geneticist

To learn more about agriculture careers visit agexplorer.com. You can also find career profiles at Careers in Corn.

If you have questions please email education@ksgrains.com

 

 

 

 

Growth Life Cycle of a Corn Plant provided by Texas North Plains Groundwater Conservation District

 

 

Any educator electing to perform demonstrations is expected to follow NSTA Minimum Safety Practices and Regulations for Demonstrations, Experiments, and Workshops, which are available at http://static.nsta.org/pdfs/MinimumSafetyPracticesAndRegulations.pdf, as well as all school policies and rules and all state and federal laws, regulations, codes and professional standards. Educators are responsible for abiding appropriate legal standards and better professional practices under a duty of care to make laboratories and demonstrations in and out of the classroom as safe as possible. If in doubt, do not perform the demonstrations.

About Kansas Corn STEM

Investing in Kansas teachers and students is a priority for the Kansas Corn Commission. We are committed to providing materials and training to support STEM education while fostering an understanding of how corn farming and agriculture fit into our daily lives. Professional development workshops are offered to teachers seeking to expand their knowledge and inquiry-based teaching skills. Workshop participants receive free lab supplies needed for the lessons.

Workshop Info

This lesson is the work product of the Kansas Corn Commission. Our lessons are written in collaboration with Kansas teachers for use in the classroom. Teachers may copy and share this curriculum. Use of this product for commercial or promotional use is prohibited without express permission of Kansas Corn.

Newsletter Sign Up

Each quarter we release a newsletter written by teachers for teachers. This is an easy way to keep up with what is happening at Kansas Corn STEM.

Subscribe Today!