Results

Careful interpretation of the data allows speculation to be made on our hypotheses. The total number of worms collected from each of the three trials can be viewed in Table 1, which also reveals the number of worms collected from each set of bins during all three trials. The totals were calculated by adding the number of worms found in the specified location of each bin. Figure 4 illustrates the overall location of worms collected in the experiment, showing that the greatest number of worms was found in the grass mixture soil. Also, worms preferred a soil with newspaper or grass over potting soil. To determine if these results were do to chemical factors of the soil, the pH and nitrogen levels were measured for each soil type (Table 5).

The results of this experiment support our first hypothesis and show that red wrigglers prefer soil with a source of organic matter over potting soil, which does not have a source of organic matter (Figure 1 and 2). Grass and newspaper served as our source of organic matter in this experiment. The conclusion that earthworms prefer soil with either grass or newspaper over potting soil is confirmed by two t-tests. This determines that these results are statistically significant due to a p-value of 0.0000029 and 0.006128 for experiments completed with grass and newspaper respectively (Tables 2 and 3). The differences between these data sets are statistically significant because the p-value is less than 0.05.

These results do not support our second hypothesis that red wrigglers will prefer a grass mixture soil over a newspaper mixture soil (Figure 3). A t-test reveals that the differences between the two data sets are not significant due to a p-value greater than 0.05 (Table 4). Therefore, the variation between the worms found in a grass mixture or a newspaper mixture is not statistically significant and does not support our hypothesis that red wigglers will prefer a grass mixture soil over a newspaper mixture soil.

Table 1. Totals of worm (Eisenia foetida) location in different conditions from three trial experiments.


Table 2. T-test assuming equal variances (potting soil vs. grass mixture)


Table 3. T-test assuming equal variances (potting soil vs. newspaper mixture)


Table 4. T-test assuming equal variances (grass mixture vs. newspaper mixture)


Table 5. Average pH and nitrogen levels of three soil types.



Figure 1. Total number of worms (Eisenia foetida) found in potting soil or grass mixture from containers with potting soil vs. grass mixture from each of three trials.


Figure 2. Total number of worms (Eisenia foetida) found in potting soil or newspaper mixture from containers with potting soil vs. newspaper mixture from each of three trials.


Figure 3. Total number of worms (Eisenia foetida) found in grass mixture soil or newspaper mixture soil from containers with grass/soil mixture vs. newspaper/soil mixture from each of three trials.


Figure 4. Total number of worms (Eisenia foetida) found in potting soil, grass, or newspaper in all containers from each of three trials. The final column is the sum of worms found in grass and newspaper during each trial of the experiment.