TA NOTES FOR FERTILIZER AND WATER QUALITY
1. Students can answer goals 1 and 2 by researching fertilizer in texts or via the internet. More industrious students may head to the nearest garden supply and read the label. You should let them come to this conclusion on their own. They should realize that not all research is experimental, even in chemistry.
2. The macronutrients are nitrogen, potassium, and phosphorous. Nitrogen is usually in the form of an ammonium salt and/or urea. Other fertilizers may also contain nitrates. Potassium is usually provided as potash (K2O). Phosphorous is usually provided as a phosphate salt.
3. Ammonium and urea can be determined qualitatively by reaction w/ 6M NaOH which will produce the odor of ammonia. The solution with the NaOH may also be heated in an evaporating dish with a watch glass on top. The condensate on the watch glass should test positive for pH < 7 with litmus paper.
4. Tests for potassium are beyond the scope of this course.
5. Phosphate can be precipitated as barium phosphate, lead phosphate, or silver phosphate.
6. Ammonium phosphate is available for students to use to test their procedures.
7. Clay pots and potting soil are available for modeling the application of fertilizer to the golf course. Students can fertilize the soil and let it sit for a week. The next week they can run water through the soil to simulate rain and collect the water that passes through. This water can then be tested for the presence of nitrogen and phosphorous.