Troubleshooting

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Some basic advice...
  • Pants, boots, gardening gloves and long sleeved shirts are especially useful for avoiding insects, mud, poison ivy and other irritating plants/insects (see figure 1)
  • Bug spray is also suggested, especially near the water where insects breed               
  • Always have the medical bag and walkie-talkie nearby incase of a medical emergency
  • Science goggles and gloves should be worn whenever chemical are present
  • Make sure to plan in advance so that you will always have the appropriate equipment and materials with you

figure 1: What you should wear: long pants, a long-sleeved shirt, bug spray, gardening gloves and boots (while outside)

Things to keep in mind...

figure 2: The backwoods of Roland Park Country School, the general setting of our experiment. 

Make sure that the sunlight is relatively the same in each plot.

 

figure 3: Our water source, the main resource for out independent variable. 

Make sure it is clear and you take water from the same spot each time.

  
Since water is the independent variable, it is critical that you choose very dry areas of soil to mark your plots. If you are lucky enough to have your plots located near a water source, be sure that the water in each 2L beaker looks about the same (amount of sediment). see figure 3

 
Because Iron is the dependant variable, make sure you test the iron levels at approximately the same time. This will give you more accurate results.  Remember that iron should be converted into parts per million. Also, remember to perform pH tests on the wet soil. If you forget to collect the wet soil, you can always hydrate the dry soil in the bags. Don't forget to test the pH level of the water you are adding to each plot.

 
The soil without water added to it is the negative control, and should be excluded from extra water, and used for comparison, giving that land's original iron content. The soil plot should, however, be near the other plots that do have water added, so that the soils will still be very similar.
 
The soil from the floodplain is the positive control, and will also be used in comparison. It is vital that you chose an area that is very dense and presumably iron-rich as well when performing this experiment.
 
Since there are many factors to control for this experiment, make sure that the water is always taken from the same place in the pond or creek, to assure that the temperature and chemical content of the water will be relatively the same. Also make sure that in choosing your plot, that the plant life, soil composition and sunlight amounts are identical. (see figure 2)

Additional pointers...

  • When selecting an area to mark out plots, make sure that the soil, plant diversity, and sunlight are about the same; try to avoid rocks, roots and slopes (see figure 5)
  • Always wash the core sample testers between uses
  • Bring a mallet when taking the soil core samples incase the soil is hard and dry
  • Be sure to take all soil extractions at the same time, since the soil is still alive and changing
  • Always check to make sure that the stream water is relatively clean and that each batch of water has a similar amount of turbidity; be sure to take all of the water from the same place for all trials (see figure 3)
  • Be sure to allow the water to absorb into the ground before adding more (see figure 4)
  • We recommend using plastic zip-lock bags for the soil core samples
  • For baking the soil samples, we recommend creating 6 aluminum foil bowls. To make these bowls get a strip of aluminum foil (approx. 1ft by 1ft), place your fist in the center of the sheet and then scrunch around your fist to create a bowl
  • Always use new bags if you choose to put the dehydrated soil back into plastic bags to measure the new mass so that the results are not skewed by any excess water/soil remaining in the old bags
  • Remember to wash off all test tubes, stirring rods, spot plates, and other materials to avoid contamination
  • Always use oven mitts to remove the trays from the oven
  • For the most accurate data, take daily samples from the positive and negative controls as well
  • We found the La Motte Test Kit to be extremely useful in conducting our chemical experiment http://www.lamotte.com/
  • If you happen to forget to do pH tests on the soil before baking them, you can always re-hydrate the soil samples using distilled water (be sure to add the exact amount of water that was baked out and allow it to fully absorb into the soil prior to conducting any experiments)

 

figure 4: Be sure to wait until the water has absorbed into the soil before adding more

 

figure 5: Make sure that all of the plots are labeled with flags, and each plot has approximately the same amount of sunlight, plant diversity and soil type