After students understand the fertilizer grade and its components, give each pair a picture, or have them find their own picture of fertilizer bags. Students then calculate the nutrient content of the bag of fertilizer.
Students should save their nutrient content information for the next activity.
Activity Two: Testing Soil for Fertilizer Application
Students learn about the soil nutrients in their local environment.
Two class periods, may be spread out over time depending on whether you send your soil samples out for testing or conduct the tests in your classroom.
Call your local office of the Natural Resources Conservation Service (NRDC) and see if they will analyze soil samples for your class. You can locate your local NRDC office using the U.S. Department of Agriculture web site: http://offices.sc.egov.usda.gov/locator/app
Another alternative is to purchase a soil sample kit so your students can test the soil themselves. Many different options are available on-line. One example is eNasco’s Soil Test Kit available for $13.35. This kit has enough equipment to test the pH, nitrogen, potash, and phosphorus for 10 soil samples. You can order online at www.enasco.com.