Blog 9

I conducted statistical tests of significance to assess if the differences I was seeing between my 2 groups were potentially due to the earthworm castings and not chance alone. For each element for each of the 2 groups, I got the mean and standard deviation of n=3 values (Baseline, Cycle 1, and Cycle 2). I then did a 2 sample t test with my null Hypothesis not equaling my alternate Hypothesis. Here are the p values:

N: 0.20

P: 0.16

K: 0.31

Mg: 0.21

Ca: 0.03

Na: 0.88

S: 0.66

Zn: 0.0045

Mn: 0.75

Fe: 0.34

Cu: 0.43

B: 0.98

Both Ca and Zn’s p values are below the significance level 0.05 indicating that there is convincing evidence that the presence of earthworm castings may result in this difference in these elements between the Control and Experimental groups.