1. Fertilizer Survivorship/Growth Effects on Earthworms
Jonathan Pizzutti
Central Catholic High School
Grade 11

2. Problem
Inorganic fertilizers contain substances that can potentially harm the ecosystem.
Fertilizers may be harming earthworms that naturally enrich soil.

3. Inorganic Fertilizer
Substance that increases the ability of soil to support and maintain plant growth using chemical materials.
Chemical ingredients include nitrogen, potassium, and phosphorus.
Faster than organic fertilizer.
The cost to produce these inorganic
fertilizers takes up almost 2% of the
world’s energy production.
The fertilizer used in this experiment
is Scotts® Turf Builder®.

4. Earthworms
Terrestrial annelid worms that belong to the Oligochaeta class.
Mainly live in soil, but some species live in decaying plant matter, manure, decaying logs, acidic humus, and the mud in streams.
Literally eat their way their way
through earth or organic material
when burrowing.

5. Earthworm Fertilization
Earthworms pull in organic substances and turn them into humus that is nutrient and mineral rich.
Constantly burrow through soil causing it to mix and aerate allowing excess water to drain and air to enter and leave.
Have been shown to dramatically increase phosphate, nitrogen, and potash in soil.
Is much less expensive than inorganic fertilization.
Many farmers and gardeners buy earthworms for this fertilization.

6. Purpose
To determine whether inorganic fertilizers have an effect on the survivorship or growth of earthworms.

7. Hypotheses Hypothesis
The inorganic fertilizer will significantly decrease the survivorship of the earthworms.
Null Hypothesis
The inorganic fertilizer will have no significant effect on the survivorship or growth of the earthworms.

8. Materials -30 healthy earthworms -a bag of Scotts® Turf Builder®
-a medium bag of regular soil
-21 large plastic cups
-cardboard
-a scale that measures in grams
-a measuring cup that measures in ml
-a liter of water
-a graduated cylinder that measures in ml
-latex gloves
-a permanent marker

9. Procedure
1) In seven of the plastic cups, made seven different combinations of soil and fertilizer in the amount of 200 grams.
2) Thoroughly mixed the mixtures into their designated cups by shaking and by hand.
3) Made two duplicates of each of the cups.
4) Inserted two pieces of cardboard into each of the cups to make three separate sections for the worms.
5) Weighed each worm individually with the scale.
6) Recorded the weight of the worms.
7) Added the worms to their designated sections of the plastic cups.

10. Procedure (continued)
8) Covered the worms with a layer of the mixture.
9) Added 10 ml of water to each of the sections with worms.
10) Waited 24 hours.
11) Recorded which worms are living and which have died.
12) Disposed of any dead worms.
13) Lightly shook and rubbed each worm to clean off any excess dirt.
14) Repeated steps 6-11 two more times.
15) Repeat steps
16) Repeat steps 5-6.

11. Concentrations Amount of Soil Amount of Fertilizer Concen-tration 0%
(Control)
.001%
.01%
.1% 1%
10%
20%
Amount
of Soil
200 g g g
199.8 g
198 g
180 g
160 g
Amount of
Fertilizer
0 g
.002 g
.02 g
.2 g
2 g
20 g
40 g

12. Results
The earthworms in the mixtures with 1%, 10%, and 20% concentrations all died within the first day.
The earthworms in the other mixtures survived the entire four day trial.

13. The Effects of Inorganic Fertilizer on Earthworm GrowthY
P-Value is
Fertilizer Concentration X
Day of the Experiment

14. Hypotheses Hypothesis Accepted
The inorganic fertilizer will significantly decrease the survivorship of the earthworms.
Null Hypothesis Rejected
The inorganic fertilizer will have no significant effect on the survivorship or growth of the earthworms.

15. Errors
Mistakes could have occurred during the preparation of mixtures.
The weight of the worm could have been slightly increased by soil stuck to its body.
The mixtures could have been contaminated in some way.

16. Limitations: Extensions: -Amount of time to conduct the experiment.
-Amount of worms available to test.
-Some equipment used was not professional.
-The environment was not ideal for the earthworms.
Extensions:
-Do more trials at smaller concentrations of fertilizer
-Use different brands of fertilizers.
-Use different types of worms and other species.

17. Sources
Bailey, Kenneth. "Fertilizer Homepage." North Carolina Cooperative Extension: Home. 26 Feb Web. 28 Jan <
"Biology of Earthworms." Earthworms Info. 19 Aug Web. 26 Jan <
Conrad, Jim. "Earthworms." Backyard Nature with Jim Conrad. Web. 10 Dec <
"Inorganic Fertilizers." Indoor Gardening Guide. Web. 10 Dec < care/Inorganic-fertilizers.html>.
Frankel, Zorba S. "Boosting Earthworm Populations and Fertilizing With Worm Castings." Worm Digest. 11 Sept Web. 28 Jan <