Overview:

Corn needs about 24 inches of rain to produce a good crop. In Kansas, larger amounts of ram fall in the eastern part of the state compared to the western part. It would be logical therefore, that the corn production would be much higher in the eastern part of the state compared to the western part. This is not true, however, and it will be the students job to solve the mystery of how more corn can be produced in the west where there is much less rainfall than in the east.

Grade Level: 3-6

Geographic Themes:

Location, Place, Human-Environment Interaction, Regions

 

National Geography Standards, Grades K-4:

#11	The geographically informed person knows and understands the patterns and networks of economic interdependence on the earth's surface.
#14	The geographically informed student will know and understand how human actions modify the physical environment.

Kansas Social Studies Standard for Benchmark, Grade Levels 8-K:

The student will understand the connections among people, places, and environments in the classroom, local school, community, Kansas, the United States, and different regions in the world.

 

Outcome:

Students will draw conclusions about the importance of irrigation to southwest Kansas.

 

Performance Objective:

The student will construct and explain a graph comparing the average annual rainfall for certain counties to the average annual corn production for those counties using charts and maps.

 

Vocabulary Terms (see Glossary):

corn production rainfall map

graticule referencing system (map grid) irrigation

Materials Needed:

• County rainfall map of Kansas
• Table that gives corn production by county in Kansas
• Graph paper
• Partially completed chart comparing 1994 rainfall vs. 1994 corn production in Kansas counties

 

Procedure:

1. Bring to class several foods which are made from corn and try to get the students, through discussion, to discover they are all made of corn.
2. Discuss with students how much water it takes to produce corn.
3. Give students a county rainfall map of Kansas, and they will identify the counties that they think would be high corn producers and why.
4. Give students the partially completed chart of Rainfall/Corn Production for 1994, and they will complete the rainfall section of the chart using information from the rainfall map of Kansas using the graticule referencing system (mapping grid). They will round the rainfall to the nearest inch to complete the chart.
5. Give each student graph paper; they will construct a bar graph of rainfall in selected counties of Kansas using information from the Rainfall/Corn Production Chart they have completed. Color the bars light blue.
6. Next give the students the 1994 Corn Production Table and have them complete the Rainfall/Corn Production Chart. Round the bushels to the nearest million.
7. Complete the bar graph (using yellow), showing the corn production of the counties by using the label on the right side of the graph, "Corn Production in Millions of Bushels.", (Use the completed Rainfall vs. Corn Production Chart to construct the graph.)
8. Now look at the graph and compare the amount of rainfall to the amount of corn produced by county discuss how it could be possible to grow more corn with less rainfall. The students will discover that irrigation must be used.
9. The students will transfer information from a table and map to an incomplete chart. They will then round these numbers and produce a graph which compares information from the chart. The students will explain in writing, what they learned by comparing the information shown on the graph and what conclusion they can make from this information. This will solve the mystery of the corn production in Kansas.

 

Assessment:

Check students' graphs and papers for accuracy of information.

 

Extension:

Ask the students what they know about irrigation to prompt discussion in this area.

Show pictures or slides of the different types of irrigation that have been used through the years.

Ask the students what is bad and what is good about each type, remembering this is western Kansas where the humidity is very low.

 

Furrow Irrigation:

Pro: lower irrigation costs

Con: uneven distribution of water down the rows, lots of evaporation, high labor and management requirements

 

Center Pivot - Broadcast:

Pro: is permanent structure, can be moved from field to field, more even distribution of water on field

Con: expensive, doesn't get corners, won't work in all fields, high evaporation rate

 

LEPA - Drop Nozzle Pivot Irrigation:

Pro: cuts down on evaporation, takes fewer man hours, more even distribution in field, can spread insecticides and fertilizer at the same time as watering, can be moved from one field to another

Con: expensive, doesn't get corners, won't work in all fields

 

Additional Extension:

• Ask the students where the water comes from for the irrigation. Explain and demonstrate an aquifer.
• Using an overhead, you can show where the Ogallala (High Plains) Aquifer covers Kansas. From this information compare it to the counties producing so much corn with irrigation.
• Ask: Do you notice any correlation between the aquifer and the corn production in the counties we used in our bar graph?
• Using a straw, drink a glass of water in front of the class and ask them what happens when you use all the water in your container?
• How can it be replaced? Can it be replaced the same way in the aquifer? Or how is it replaced in the aquifer?

 

Resources:

• Kansas Department of Health and Environment (1986). Water quality assessment report. Topeka, KS: Author.
• Kansas State Board of Agriculture. (1994). Kansas farm facts 1994. Topeka, KS: Author. (Available from Kansas Agriculture Statistics, P 0. Box 3534, Topeka, KS 66601-3534, phone 913-233-2230.)
• Kansas Water Office. (1994). Kansas irrigation water use 1994. Topeka, KS: Author. (Available from Kansas Water Office, 109 S.W. 9th St., Suite 300, Topeka, KS 66612.)
• Rogers, D. H. (n.d.). Managing furrow irrigation systems (Irrigation Management Series). Manhattan, KS: Cooperative Extension Service.
• Rogers, D H., Lamm, F, & Manges, H. (n.d.). Managing LEPA bubblers and flat sprays on corn (Irrigation Management Series). Manhattan, KS: Cooperative Extension Service.
• Rogers, D. H., Lamm, F, & Spurgeon, W (lid.). LEPA irrigation management for center pivots (Irrigation Management Series). Manhattan, KS: Cooperative Extension Service.

 

Top of Page | Lesson Plan V Content Page
Lesson Plans Content Page
Previous Lesson | Next Lesson

---

FHSU Geoscience | Kansas Geographic Alliance
National Geographic Society | Kansas Water Office
Fort Hays State University | Kansas State University

e-mail: pphillip@fhsu.edu

irc staff 11/13/97 (updated kn 06/18/99) Disclaimer