Location: My Backyard
You need to dry it out for between 16-24 hours to get all the moisture out. Keep it in the oven with the lid off. Keep the temperature between 105-115ºC (220-240ºF about) for best results. Make sure to only do one sample testing at a time.
http://www.environment.nsw.gov.au/resources/soils/testmethods/mc.pdf
http://www.environment.nsw.gov.au/resources/soils/testmethods/mc.pdf
When you take the mass before and after you have to find the change in percentage so you can find the percentage of moisture that was in the soil sample after each visit. If you take the difference in the two masses it will be different based on how much dirt you used. Use at least 30g of the material you are drying out.
http://www.currentresults.com/Weather/US/average-state-precipitation-in-fall.php
http://www.currentresults.com/Weather/US/average-state-precipitation-in-fall.php
Average rainfall in the months of September-November decreases steadily. If you look at the average rainfall in Michigan for the summer and winter months it steadily decreases as time passes. Spring time is the only time when the precipitation increases.
Hypothesis: If the amount of time increases, then the amount of soil moisture will decrease because it doesn’t rain as much in the fall and there isn’t much precipitation until snow falls.
5 controlled variables
-same location of rain gauge
-amount of time spent in the incubator
-depth of the sample dirt
-location of sample dirt
-same container for the dirt in the incubator
Materials
-ziploc bags, small garden shovel, bucket for rain gauge, incubator
Procedure:
1. Gather a bucket for a rain guage on the first visit only, a small gardening shovel, and a small ziploc bag.
2. Go to the selected spot in the plot of land
3. Use the small shovel to dig a small hole about 3 inches deep.
4. Take a shovelful of soil and place into the ziploc baggie.
5. Put your name on the bag and your visit number so you won’t lose it in the incubator.
6. Take the bag to school
7. Put a crucible on the scale and tear it so it will subtract the weight of the crucible.
8. Place your dirt sample in 3 crucible and take the masses.
9. Place your crucibles into the incubator for between 24-48 hours depending on the moisture in the soil.
10. Take the soil sample out of the incubator when finished.
11. Take the mass of the soil sample once again.
12. Take the percentage of change between the two masses not the difference between the two.
13. Write down the percentage change on a chart
14. Repeat steps 1-13 for each of the 6 visits.
Data Tables
Percent Change in Mass
depends on the Date
| |||
Visit No#
|
Before Masses (grams)
|
After Masses (grams)
|
Percent Changed (percent)
|
#1 Sept 9
|
27.73, 28.28, 28.30
|
26.01, 26.59, 26.62
|
6.2, 5.9, 5.9
|
#2 Sept 25
|
27.81, 31.08, 28.23
|
26.52, 29.48, 26.88
|
4.6, 5.1, 4.8
|
#3 Oct. 14
|
28.78, 28.76, 26.55
|
26.68, 26.53, 24.75
|
7.3, 5.1, 4.8
|
#4 Oct. 30
|
26.78, 26.69, 28.02
|
24.66, 24.79, 25.67
|
7.9, 7.1, 8.4
|
#5 Nov. 13
|
25.59, 30.65, 29.70
|
23.54, 28.44, 27.44
|
8.1, 7.2, 7.6
|
#6 Nov. 22
|
27.78, 28.65, 28.52
|
25.61, 26.50, 26.24
|
7.8, 7.5, 7.0
|
Source:
|
Daniel Walters
|
November 2013
|
Precipitation depends on the Dates
| |
Dates
|
Precipitation (in.)
|
Sept. 2-8
|
0.00
|
Sept. 9-15
|
0.61
|
Sept. 16-22
|
0.90
|
Sept. 23-29
|
0.45
|
Sept. 30-Oct. 6
|
1.45
|
Oct. 7-13
|
0.27
|
Oct. 14-20
|
3.03
|
Oct. 21-27
|
2.88
|
Oct. 28-Nov. 3
|
2.24
|
Nov. 4-10
|
3.25
|
Nov. 11-17
|
1.74
|
Nov. 18-24
|
1.57
|
Nov. 25-Dec. 1
|
0.00
|
Source:
|
Daniel Walters November 2013
|
Graphs
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Conclusion
My data showed that the moisture in the soil changed over time according the amount of precipitation. This data didn’t support my hypothesis. I thought that the soil moisture would decrease over time. After my first three visits the soil moisture wasn't increasing or decreasing. The graph of precipitation shows this in precipitation as well. It wasn't trending up or down. With my last three visits the soil moisture had a decreasing trend. The precipitation graph and data directly correlates with this decreasing trend.
To change this experiment, I would have visited at least once a week. It would give me more data to work with. Also I would be able to see how directly the moisture correlates with precipitation. I would have also taken samples in more locations. This would tell me if certain areas of soil are more moist than others. I would have liked to make the field study start earlier that way I would have been able to see change over a longer period of time, but I realize that first semester is only so long.
Data has shown that over time in the fall that the average rainfall in the months of September, October, and November gradually decrease. My graph with precipitation shows that in the month of september there was very little precipitation. In the month of october there was a sudden spike and then it began to gradually decrease until the present date. Scientifically the average rainfall decreases and that correlates with my hypothesis that there will be less rain, therefore less soil moisture. My data didn’t clearly show one way or another. This fall we didn’t get the average rainfall per month. In the month of October we were well over the average precipitation and this caused the soil moisture to spike in the month of October as well. Also these past fall months it was more sunny and warm. More sunshine caused for more evaporation of water vapor into the air. When more water was evaporated this caused more precipitation during these months.
Sources:
