Moisture Content Analysis
Methods
1 gram of soil from each of the samples was added to a test tube and then dried in an oven set to 105-110 ° C for one week.
Soil Moisture Content
Figure 2
Legend
Moisture Content in Non-Rain Garden and Rain Garden Soil Types. After collecting soil samples from a non-rain garden section and a rain garden section, we determined the moisture content in each and set our data as percentages (ratios) of moisture content. The average of our moisture percentage is represented on each box and whisker plot by the "X", and the line in the middle of the plots is the median. The plot is divided into four sections or quartiles, the two "whiskers" on the outside, and the "boxes" on the inside. The inner points are used to identify any potential outliers between the box section of the plot, or they may be used to determine any differences between data sets. We were able to receive our moisture content values by measuring the mass difference from the soil samples with and without water, and then finding the overall percentage of moisture lost. An unpaired t-test assuming unequal variance was used to determine our p-value of 0.283, with our critical value being 0.05.
Evidence
As shown by our box and whisker plots, we can see that the spread of our data within non-rain garden soil moisture content was much, much smaller than the spread of rain garden soil moisture content. The average moisture content ratio for the non-rain garden samples was 27.96% and 31.47% for rain garden samples. The moisture content ration for the rain garden samples was slightly higher (12.55%) than the non-rain garden samples. The p-value for the moisture content ratio was 0.238, with a critical value of 0.05. This shows that there is no significant evidence that the moisture content ratio between the two samples is significantly different.
Conclusion
Based on our evidence we can conclude that the moisture content for the two different collection sites are not significantly different. We are able to determine this based on our p-value calculated to be 0.283 which tells us that there is significant difference between the two sites if the value is below 0.05, which our value is not. We are quite confident in our evaluation there being no significant difference between the two sites. Our p-value we calculated helps us to evaluate and have confidence in our conclusion there is no significant difference between the two sites.
Explanation
Our two collection sites having similar values for the moisture content can be explained by the clay-like texture of the soil. Soil that is more clay-like is better at water retention, therefore the values can be explained by the reasoning the clay soil was able to better retain the water (Rasheed, 2022). We also collected our samples on and after a day of raining therefore we can expect our results to show higher moisture content than a day where it was sunny and dry. We can also assume there is more organic matter in the soil collected from this site as it has been seen that soil with more organic matter is better at retaining moisture (Rasheed, 2022).
