of corn production Growing Season (and the environmental conditions that appear to limit its extent) Days between frosts Precipitation 120 160 200 240

Corn Production

25 50 100 150 Centimeters Glaciation Topography

A region is a group of places that are close to each other and similar in some important way. In this activity, you will define a region called the Corn Belt and formulate hypotheses about the conditions that limit its extent in different directions. That kind of thinking can help build a foundation for trying to predict how global warming might change farm production. 1. Draw a line around the Corn Belt - the area where corn production is a major use of land. (You have to decide how close the dots should be for corn to be "a major use of the land.") 2. It seems logical that corn would need a certain number of frost-free days in order to mature. Roughly how many days does corn seem to need between the last freezing temperature in spring and the first one in fall? _____ That marks the northern limit of the Corn Belt. 3. Examine the maps, and briefly describe an environmental condition that seems to mark the western limit of the Corn Belt.

4. What environmental condition(s) seem to mark the southern limit of the Corn Belt?

5. What environmental condition(s) seem to mark the eastern limit of the Corn Belt?

6. On a separate page, describe what might happen to the Corn Belt with global warming. Hint: warmer air also causes more evaporation, so corn might need more rain, too.

©2013 P Gersmehl Teachers may copy for use in their classrooms. Contact [email protected] regarding permission for any other use. Teacher’s Notes – A Region of Corn Production Big idea: Drawing a line around a region is a judgment call – someone has to decide which places are similar enough (and close enough to each other) to be grouped together and shown with a single color on a map. Once we have put places in a region, we can ask questions about the conditions that seem to limit the extent of that region. The answers to those questions can help us plan for changes that might occur in the future. Subordinate objectives: - to identify the environmental conditions that favor corn production - to describe how global warming might cause a region like the Corn Belt to “move” Possible setup information: Corn is the most important crop in the world, for food and for fuel. Ask if students know what conditions are needed for it to grow. If not, note that we can sometimes learn those conditions by studying maps, without having to do research on plant physiology. Possible additional or alternative setup: Hold up an atlas or textbook map of agricultural and ask whether students know where that kind of map comes from (and why we should care). Point out that someone had to gather information from local observations, census records, or satellite images and make a decision about where to draw the line around each region. Those lines could change as a result of global warming, and that could cost a lot of money and millions of jobs if we don’t take some precautions. An activity like this one (while handing out) is part of that planning process, whether it is done by scientific researchers, the government, or private businesses! Vocabulary: boundary density frost-free season precipitation region spatial thinking Procedure: The worksheet is the core of the activity. Like other activities in this book, this can be done as an individual worksheet, small-group activity, whole-class discussion (with or without a projector), or takehome project. It works better when a larger task (e.g. studying about ethanol or global warming) justifies doing an activity like this in order to master the skill involved. Answers: 1. Line should enclose a region around , , and ; it should probably ignore outliers in western , the Carolinas, or Pennsylvania – corn production may be locally important in those areas, but few people would call them part of the Corn Belt. 2. 120 days 3. 50 centimeters, or about 20 inches 4. the area covered by Pleistocene glaciers, which smoothed the land and added new soil; one could also make the case that too much rain (>100 cm) can harm corn 5. the area covered by Pleistocene glaciers, OR the more rugged land of the Appalachian Plateau (there is a connection here – the highland probably prevented further advance of the glacier!) 6. This is the billion-dollar question. It is true that warmer conditions might allow corn to grow farther north, but drier conditions might also cause the western edge to move east. Moreover, the soils in northern and are thin and rocky, a result of cold climate and glacial scouring – so a simple-minded “It’s OK, we don’t need to worry, the Corn Belt will just shift north” is dangerously naïve. Extensions, supplements, and GIS applications: The CD folder has an explanatory multimedia presentation. The lesson can fit into a general discussion of agriculture, rural land use, ethanol production, energy use, or global warming. With a GIS, students could analyze different crops, compare their extent with more precise maps of rainfall and growing season, and look at satellite images to refine their impressions of land-use patterns in various states. Complication: This lesson’s focus was on corn, which is usually the most valuable field crop in places where it grows well. A less valuable crop, such as wheat or hay, often has at least one of its regional borders marked by the conditions that limit a more valuable crop. In other words, it’s not too hot or rainy to grow wheat in central Iowa, it’s just that corn does much, much better!