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.
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
Students will be doing three lessons, all centered around the background knowledge below. Complete this unit’s lessons in the following order:
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”.
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:
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:
Procedure for Lesson:
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):
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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.
Investing in teachers is a priority therefore the Kansas Corn Commission is committed to providing materials and training to help teachers excel in the classroom. Teachers who seek to expand their knowledge and skill of connecting science with agriculture are encouraged to attend a Seed to STEM workshop.