Activities for Module II, Corn, Beans, and Burgers

Activities for Section A: Field Crops in the food system

• Activity 1: The Crops on our Plates
• Activity 2: How Much Corn is 2 Billion Bushels?
• Activity 3: A Look at Processing and Distribution

Activity 1: The Crops on Our Plates

Purpose: Have students analyze the contribution of major field crops to their diet.

Advance preparation: Ask students to bring a week’s itemized grocery receipt or shopping list and some ingredients labels to class. You can use the sample grocery receipt in the curriculum, but the exercise will have more impact if the students use lists from their own families.

Estimated time: 15 to 30 minutes

Divide students into small working groups.

Make sure each group has at least one grocery list to work with.

Ask students what they think the major field crops of their state are. Explain that 3 crops (field corn, soybeans, and alfalfa) account for more than 79% of Wisconsin’s cropland and more than 87% of Iowa’s cropland.

Ask students to:

1. Identify which items in the week’s groceries come from the 3 major field crops (note: sweet corn is considered a vegetable and is not included in the corn acreage.) You may wish to remind students that sweeteners, oils, and emulsifiers in processed foods are mostly derived from corn and soybeans. They can refer to the labels they brought in to get an idea of the role of these ingredients.
2. Estimate the percentage of their diet supplied by the 3 major field crops, based on their findings from the grocery list.
3. Assess the nutritional contribution of field crops to their diet.

Have each group share its findings with the class and use class discussion to draw some broader conclusions.

Suggested points to cover include the following:

• Little of the food we eat is directly supplied by our principal field crops.
• Field crops indirectly contribute to the food we eat as livestock feed used to produce dairy products, eggs, and meat, and as ingredients in processed foods.
• Corn sweeteners and starches, soy oil and stabilizers, and other additives derived from field crops are typically present in small quantities and add little nutritional value to a diet.
• For most people in the Midwest, foods derived from field crops account for less than half of their diet—why is that when well over half of cropland is devoted to these crops? (One reason is that we lose 75% to 90% of the nutritional value of the field crops when they are fed to animals because it goes to keeping the livestock alive. Another reason is that Iowa and Wisconsin export animal products and import vegetables and grain products for human consumption).
• Ask if students can think of examples where principal field crops are also a major direct component of the local diet. (Rice in much of Asia, corn in Mexico and Central America, to a certain extent wheat in the US high plains).
• Do students’ findings track with national statistics on use of field crops? (see Background, How do we use these Crops).

Sample Weekly Grocery List

Sample Weekly Grocery List

Activity 2: How much corn is 2 billion bushels? (optional)

Purpose: Give students better feel for the amount of corn produced. Short exercise in math problem solving.

Advance preparation: none

Estimated time: 10 minutes

Ask students to figure out the answer to the following question:

Iowa’s annual corn harvest is usually around 2 billion bushels. If you loaded semi trucks with 2 billion bushels and lined them up bumper to bumper, how far would they stretch?

According to the Iowa Department of Transportation, a large semi holds around 910 bushels, and 879 large semis lined up bumper to bumper would stretch around 11.5 miles (see http://silosandsmokestacks.org/resources/images/scans/compareDOT.gif).

Answer: The line of trucks would stretch 29,206 miles, or more than the circumference of the earth (which is a little under 25,000 miles). Luckily, most grain is transported much more efficiently in railroad cars and on barges.
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Activity 3: A Look at Processing and Distribution

Purpose: Have students explore the complexity of processing of field crops and learn how hard it is for consumers to find out where their food comes from and who controls processing and distribution.

Advance preparation: Have each small group bring an example of a food containing one or more of the principal field crops to class. Or develop a list of foods containing field crop ingredients (see http://www.soystats.com/2003/Default-frames.htm for information on soy products and http://www.iowacorn.org/cornuse/cornuse_6.html for examples of foods with corn-based ingredients). Print out a copy of the flowchart for a soft drink (MS Word Document).

Estimated time: 15 minutes to one hour or more

Break students into small groups. Assign each group a different food derived at least in part from one of the state’s main field crops. If students have brought sample foods to class, have the groups use those items.

Show students the sample flowchart for a soft drink.

Ask each group to identify the steps and actors involved in moving the field crop(s) to the final product for their food item. Ask them to develop a “field to plate” flow chart for it and present the chart to the class.

Your students will probably have trouble filling in the flow chart. Most people know very little about food processing and distribution, and the information is difficult to obtain. This even applies to many people employed in food processing, as well as the general public.

Students can begin by brainstorming what the likely processing and transportation stages are and what companies might be involved. If time allows, they can follow up these guesses with research. They can try looking on the internet, they can try to contact the company listed on the product label, and/or they can try to track the product back from the point of purchase. In the amount of time students have available, they will probably only be able to get general information, not specifics about the origin of a particular food item.
In many cases, companies are reluctant to share detailed information about the processing and movement of their products, though they may publicize generic production information. For example, development of the flow chart for the path of corn to high fructose corn syrup to soda in a grocery store took about 50 phone calls over a period of months. A few company spokespeople shared information willingly, but others failed to return phone calls or refused outright to divulge the information.

Why do this exercise if students won’t get the answers?

• They will begin to think about the various stages in the food system.
• They will learn that food does not simply arrive at the grocery store straight from farms, but that in between it is handled by a number of different people, even if it is difficult to find out who exactly those people are.