Examples: Section B1

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Using Remote Sensing

  1. Obtaining
  2. Linking
  3. Subsetting
  4. Compositing
  5. False coloring
  6. Ratioing
  7. Supervised classification


Pre-post test

Tested Classroom Activity:

Using Images section B

Activity 2

Question: Are farmers following recommended crop rotation practices?

Background on Best Crop Farming Practices :

(According to: Lipps, Pat. "Improving Wheat Yields in Ohio introduction and crop rotation." The Ohio State University Extension Research . OSU. 12 Dec. 2007 http://ohioline.osu.edu/iwy/intro.html.)

Soft red winter wheat is important to the economics of Ohio's farm and food-related industries. Wheat is the most widely grown food crop in the state. Low prices and major production problems resulting from severe winters and certain diseases have limited the production of wheat on many grain farms.

University research trials and results from farmers' fields have shown many advantages for wheat in maintaining optimum yields in the other crops grown in a rotation, especially corn and soybeans. According to research at Michigan State University, including wheat in rotations can improve yields of other crops by 10% or more. Other "hidden" values of including wheat in the rotation include improved soil quality through addition of organic matter and improvement of ground-water quality by limiting nitrogen loss during winter and spring. Additionally, corn-soybean-wheat rotation aids in weed control and helps reduce pathogen populations that attack those crops. Wheat is a significant partner in the rotation sequence to maintain farm productivity and sustainability.

Plant wheat after soybeans. A three-year rotation of corn-soybean-wheat appears to be optimum for sustained yield of all three crops. Crop rotation is the most effective method to reduce pathogen populations that affect the three crops in the sequence. The purpose is to provide enough time away from the host plant for pathogens to die out before that crop is planted again. Wheat should never follow wheat or spelt in the rotation sequence.

Soil-borne diseases, like Take-all and Cephalosporium stripe, can cause complete crop failure in non-rotated fields. Foliar diseases, like powdery mildew and Stagonospora glume blotch, may also become more of a problem. Wheat should not follow corn in the rotation because the same fungus that causes Gibberella stalk rot in corn also causes Fusarium head scab in the wheat. Planting wheat into corn residues greatly increases the risk of a severe outbreak of scab in the wheat crop. Wheat also serves as an excellent rotation crop for corn and soybeans, allowing populations of pathogens (like soybean cyst nematode and Sclerotinia) to decline before host crops are again planted in the field.

Other Research  Best Practices and Economic influences:

Two good reference for exploring the influence of economics on crop rotation is the Ohio State C.O.R.N. Newsletter published by the Agronomic Crops team at http://agcrops.osu.edu/ (search crop rotation) and the Corny News Network published through the Chat “n Chew Café by Purdue University Department of Agronomy at www.kingcorn.org   Much research encourages farmers to rotate crops but economic pressures such as demands on corn for ethanol plants, or temporary area sweeping diseases may temp farmers away from best practices. These two references indicate Indiana farmers are showing signs of not rotating crops for 2008 http://www.agry.purdue.edu/ext/corn/news/timeless/CornCorn.html because of predicted increased risk of soybean problems.

Activity Problem:

If farmers follow recommended crop rotation for NW Ohio, then every 3rd year of rotation, winter wheat should be planted. By looking at images after 6 years of rotation, 2000 and 2006, fields with winter wheat in the earlier year should also have wheat at the later date. This method does not rule out other planting rotations, such as planting wheat every other year, every year, or some other combination. However, it will indicate the maximum area following recommended crop rotation practices, which have winter wheat, planted in the first year.


  1. Create a classified image of the given image using the attached direction sheets.
  2. To futher understand why the land is color coded the way it is, make a graph of the band intensity for a red sectioon, a graph for green section, and a graph for a yellow.  Observe the band intensites in each graph. Why does yellow indicate winter wheat grown in both years?
  3. Choose 3 yellow fields and name them “ww both years.” Choose 3 non-yellow fields and name them “non-ww both years”.
  4. To save your product, create a PrtSc of your image and paste it in a word document. Reduce the image to ½ the size.
  5. Copy and paste your 3 selection windows next to your pasted image. Label the window from a red field “ww May 2000”. Label your selection window from your green field “ ww May 2006”. Label your yellow selection window “ ww May 2000 and 2006”. 
  6. PrtSc your data table box below your pasted image. Title your document: Classified image of a subset composite of LANDSAT5 NW Ohio from May 2000 and May 2006 and accompanying charts and tables.
  7. Analysis:
    Explain what the image reveals, what the graphs mean and what percentage the area of crop fields are winter wheat for both dates. Discuss any weaknesses in this procedure. Identify one or two follow up questions to investigate. Answer the original question.
  8. Save your document.