1. The Effect of Fertilizer and Pesticide on Algae Growth
Fulton Fontana
Central Catholic High School
9th Grade

2. Rationale
To determine the effects of a common fertilizer and pesticide on algae growth.

3. Fertilizer Aids plant growth and development
Scotts® Liquid Turf Builder® Lawn Food
Essential Elements: Nitrogen, Phosphorus, and Potassium
Ingredients: 29% Urea Nitrogen, 3% Solable Potash, 17% Triazone, Potassium Chloride
Enter water sources through rain runoff
20% of all fertilizer is lost through rain runoff
Could harm non-target species

4. Pesticide Repel unwanted insects, animals, and other pests
Ortho® Home Defense® Insect Killer
Contain species-specific ingredients to kill them
Bifenthrin %, Zeta- Cypermethrin %, Cis, Min,Trans Isomers 99%
Enter water sources through rain runoff
5% of pesticides are lost to rain runoff
Could harm non-target species

5. Euglena gracilis Algal-like protist
Both animal and plant characteristics
Single-celled with a flagellum
Found in freshwater, saltwater, and soil
Commonly used as a model organism

6. Chlamydomonas reinhardtii
Species of algae
Single-celled with two flagella
Found in almost every environment on Earth
Widely studied by scientists

7. Hypotheses
Null: There will be no significant variation between the effects of each concentration of fertilizer and pesticide on the growth of either type of algae. Alternative: The fertilizer and pesticide will significantly enhance the growth of either one or both types of algae.

8. Materials Chlamydomonas reinhardtii
Test Tubes (13 x 100 borosilicate culture tubes)
Euglena gracilis
Tube Rack
Scotts® Liquid Turf Builder® Lawn Food
Pipettes
Ortho® Home Defense® Insect Killer
Soil Water
Spring Water
Spectrophotometer

9. Procedure
A combination of soil water, spring water, algae, and variable was used to create 5 replicates of the following concentrations: 0%
0.5% 1%
Algae
2 ml
Soil Water
1 ml
Spring Water
1.975 ml
0.05 ml
Variable
0 ml
0.025 ml
1.95 ml
Total
5 ml

10. Procedure (Continued)
Each tube was mixed and then the absorbance was taken at 430 Nanometers in a spectrophotometer.
The absorbance of the test tubes was measured every other day for two weeks.
When not in use, the tubes were kept 1.2 meters below a 40 watt light bulb at 20 degrees Celsius for twelve hours a day. The bulb was turned off for the other 12 hours

11. Effect of Fertilizer on Euglena Growth
Day 7: P-Value =
Day 13: P-Value = 8.35E-07
Key: Blue – 0% Orange – 0.5% Gray – 1%

12. Effect of Fertilizer on Chlamydomonas Growth
Day 7: P-Value =
Day 13: P-Value =
Key: Blue – 0% Orange – 0.5% Gray - 1%

13. Effect of Pesticide on Euglena Growth
Day 7: P-Value =
Day 13: P-Value =
Key: Blue – 0% Orange – 0.5% Gray – 1%

14. Effect of Pesticide on Chlamydomonas Growth
Day 7: P-Value =
Day 13: P-Value =
Key: Blue – 0% Orange – 0.5% Gray - 1%

15. Dunnett’s Test - Fertilizer
Algae
Day
Concentration
T-Value
T-Crit Value
Significance
Euglena
Day 7
0.5%
9.20
3.03
Significant 1%
12.76
Day 13
4.96
6.36
Chlamydomonas -
Insignificant

16. Dunnett’s Test – Pesticide
Algae
Day
Concentration
T-Value
T-Crit Value
Significance
Euglena
Day 7
0.5%
1.34
3.03
Insignificant 1%
3.24
Significant
Day 13
1.56
3.64
Chlamydomonas
2.50
5.83
2.54
5.61

17. Conclusion
The alternative hypothesis was supported and the null was rejected for Fertilizer on Euglena at both concentrations. The null hypothesis failed to be rejected for Fertilizer on Chlamydomonas at both concentrations . Overall, the null hypothesis was rejected and the alternative was supported for pesticide on both algaes. The null failed to be rejected at 0.5% for both algae but was rejected at 1% for both algae.

18. Limitations and Extensions
Small Range of Concentrations
Use more Fertilizers and Pesticides
Did not Test for Combined Effect
Increase Range of Concentrations
Algal Health May have Varied
Expand Tested Organisms
Questionable Optimal Conditions - Lighting, Mixing, Temperature, etc.
Increase Replicates
Test for Interaction of Both Variables

19. Sources https://www.britannica.com/science/Euglena
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