11/1/18 Lab #11: Soil Ciliate Discovery/ Soil Metadata

Purpose: In this lab students learned about pH and soil ciliates. Students found the pH of the wet soil sample and found the water content of the sample as well. Also, the wet soil sample was observed under a microscope in order to find ciliates in the soil sample.

Procedure:

1. Obtain mass data of the dry soil sample from lab #5 and obtain the wet soil sample.
2. In order to find the water content of the soil sample, use the water content formula and the masses of the wet and dry soil sample.
3. Saturate the dry soil being careful not to flood, in the petri-dish with distilled water creating a non-flooded plate. (step was done 30 hours before lab)
4. To find the pH of the sample, transfer 1000 microliters into a centrifuge tube and place it in the centrifuge for about 30 seconds.
5. Let the soil settle and then take 20 microliters and transfer it to the lid of the petri-dish.
6. Take a small strip of pH paper and submerge it into the drop of soil sample, add another small drop on the pH paper to fully submerge it. Wait one minute before comparing the colors of the pH paper.
7. Compare the result color of the sample to the pH guide and find the color that matches best. (Record pH)
8. Next, observe the sample under a dissecting microscope by placing the petri-dish under the microscope and recording observations.
9. Then, take 10 microliters of sample and place it on a concavity slide. Observe under a compound microscope for ciliates. ( This step may need to be repeated multiple times taking different types of samples in order to find moving ciliates.) Take pictures and record observations.
10. Clean slides and put away microscopes.

Data:

Water Content:

• Formula: Wet soil – dry soil/ wet soil X 100
  • 21.8- 19.1/ 21.8 X100 = 12.4 % water

Storage:

Soil samples were stored in petri-dishes labeled: mo34F18

Conclusion:

Throughout this lab I found the water content and pH of the dried soil sample that I collected a few weeks ago. The water content was 12.6% and the pH was neutral, 7.0. My sample had a lot of soil and not much empty space in the petri dish which made it hard to observe any ciliates in the petri-dish on a dissecting microscope. However after trying over 4 times, I was able to locate a few ciliates on a concavity slide using a compound microscope on magnification 40x. The ciliates appeared small and round moving very quickly. Overall, I was successfully able to observe ciliates within my soil sample and learn how to find water content and pH level. In the future I hope to be able to further analyze soil ciliates and learn more about there function and specific characteristics.