Environmental Chemistry C

1. Environmental Chemistry C Focus on Soil Lin Wozniewksi lwoz@iun.edu

2. Safety • Students must wear: • Closed shoes • Slacks or skirts that come to the ankles • Lab coat or lab apron • Indirect vent or unvented chemical splash proof goggles. No impact glasses or visorgogs are permitted

3. Students can bring • Calculator • 1 sheet of paper on which anything handwritten is acceptable • Sheets will be collected at the end of the event • A writing instrument

4. Supervisors will provide • The instruments • The materials to test • Any calibration curves necessary • Any other testing materials necessary • Instructions on how to use instrumentation or test kits.

5. Soil Nutrients pH Fertilizers Effects of soil Temperature What plants need Contaminants How to prepare students Resources Main Focus

6. 3 Main classes of nutrients Absolutely necessary Nitrogen Phosphorous Potash Vital Calcium Magnesium Sulfur Trace Iron, Manganese, Zinc, Boron, Copper, Molybdenum Chlorine, Silicon, Nickel, Cobalt Soil Nutrients

7. Soil Testing • Test kits are available at local garden centers and Sears costing from ~$3-5. Often enough material for several tests are included • Numbers are not usually given, just very low, low, optimum, and above. • Even professional soil testers will give not only the numbers (which will vary from laboratory to laboratory and hence are unreliable) will also give the results in terms of very low, low, optimum, high.

8. pH • Many plants need a slightly acidic soil • The natural pH of most water is about 6 because of the carbon dioxide dissolved in it. • Some flowers like hydrangeas have different colored flowers in different pH soils • Many plants produce natural indicators that change colors in different pH’s

9. Calcium and Magnesium • Both Calcium and Magnesium are vital to proper plant growth • Neither are tested for in a standard NPK soil test kit • Can be tested for by testing a digested sample

10. Remediation • To raise the pH of acidic soils (below pH 5.8), add lime (limestone) • To lower the pH of basic soils (above pH 8.3) that do not contain free carbonate, add sulfur. • Since limestone is a combination of calcium and magnesium carbonate, it can be added to increase the carbonate level if necessary.

11. Fertilizers • NPK Fertilizers are only concerned with the 3 Absolutely Necessary ingredients • Nitrogen in the form of Ammonia (NH3) and Nitrate (NO3-) • Phosphorous (Usually in the form P2O5) • Potash (K+) (Usually as K2O) • The numbers on the bag tell the weights of each ingredient, in that order • There are lots of different fertilizers for various purposes

12. Fertilizers

13. Effect of Temperature • Water has a very high specific heat because of the hydrogen bonding • This means it can store a lot of heat in the bonds • Moist soils will not warm up or cool off as fast as dry soils • Most plants prefer an optimal temperature for maximum growth-they will not grow properly if too hot or too cold

14. What Plants Need • The Nitrogen is used for green leaves • The Phosphorus is used for strength and the root system • The Potash is used for fruits. • Most plants need a neutral pH around 6-6.5 • Plants need balanced nutrition and not just NPK fertilizers

15. Fertilizer Good or Bad • A good fertilization plan can be more beneficial for the environment than no fertilization • A properly applied fertilization program will promote plant growth which will prevent soil erosion • Proper fertilization means only applying what is necessary and not over applying

16. Contaminants • Are metals contaminants or trace nutrients? • It depends on the concentrations • Some copper, iron, etc. are necessary for plant development. • Plants take the metal ions up in their structure and can be used to bio-remediate area, but then the plants can not be used for food.

17. Preparation of Soil Samples • Normally to test for metal ions, the soils must be refluxed in concentrated nitric acid for about 24 hours to remove the metals to be tested for • Then the liquid is diluted. • Most of the ions are not colored and therefore need a reagent that when combined with the metal ions will be colored so the solution can be put in a colorimeter. • Since this is time consuming and dangerous, it may be advantageous to “fake” the materials to be tested for.

18. Preparation of Test Materials • Food coloring makes an extremely good coloring agent. • If dilute enough, students would be hard pressed with the naked eye to tell the difference between a liter of water with a drop of red food coloring and an iron(III) solution with phenanthrolene added • Students would have a tough time telling with the naked eye the difference between a solution of copper(II) ion and a dilute solution of water and blue food coloring. • Black food coloring makes an extremely good base to hide other colors in.

19. How To Prepare Students • Practice • In teams • With soil test kits • With instruments • With calibration curves • Make notes

20. How to Prepare Students • Have students research • Fertilizers • Plant nutrients • Environmental effects • Trace nutrients

21. Resources • Nutrient depletion http://www.youngevity.ca/misc/mineral_depletion.php • Activity - http://www-tc.pbs.org/saf/1301/teaching/teach2.pdf • With Acid Rain http://www.eurekalert.org/pub_releases/2004-03/uom-ars032604.php# • Tomato Plant nutrient requirements http://www.wikihow.com/Grow-a-Tomato-Plant • Reading Fertilizer Labels http://www.wikihow.com/Read-a-Fertilizer-Label

22. Resources • Effects of nutrient deficiency on plants http://www.uga.edu/vegetable/home.html • Soil Testing http://www.lowes.com/lowes/lkn?action=howTo&p=LawnGarden/soiltest.html • Soil Test Kits http://www.shopping.com/xDN-garden--soil_testing_kits-price_range_10_20 • Fertilizer Numbers http://www.agroservicesinternational.com/index.html

23. Rescources • Instrument labs http://education.ti.com/educationportal/activityexchange/activity_list.do?cid=us

24. Questions? • Thank You