1. The Effect of High Concentration of Carbon Dioxide on Plant Growth
By Jeremy Tran

2. Hypothesis and Problem
Problem Statement: What is the effect of high concentration of carbon dioxide on plant growth?
Hypothesis: If there is a higher concentration of carbon dioxide, then the plant will grow faster.

3. Concepts Common Bean- Phaseolus Vulgaris
Photosynthesis- The process of converting light energy to chemical energy and storing it in the bonds of sugar.
Green house gases- Impact the growth of plants by controlling how much heat gets trapped on the earth’s surface.
Carbon Dioxide- one type of green house gas. Plants use carbon dioxide so they can photosynthesize.
PPM- Parts Per Million. Unit used to measure amount of carbon dioxide.
Plant Growth- Number and size of flowers; number, size, and weight of seeds; number and size of fruits, and the amount of nitrogen in the seeds.” (Melville)

4. Regular Air (Approximately, 300 ppm of CO2)
Design Diagram
Levels
3000 ppm of CO2
1500 ppm of CO2
750 ppm of CO2
Regular Air (Approximately, 300 ppm of CO2)
Trials 1
Sample Size 12
IV: Independent Variable- Amount of carbon dioxide
DV: Dependent Variable- Plant’s growth rate, which the height of the plant will be measured in centimeters per day
Constants: Soil, Plants, Amount of water (300 ml of filtered water per day), Amount of light (same location), Room temperature
Materials: 48 bean plants (Phaseolus vulgaris), 4 Cardboard Boxes, Plastic wrap, Clear PVC tubing, Multiple plant trays,18 cm to 27 cm balloons, Soil of the same kind, Carbon dioxide tank, Metal clamps (To clamp tubing), Graduated Cylinder, Plastic funnel, Centimeter rulers, Filtered water, Drill (To drill holes in the PVC tubing)

5. Procedure
Obtain a cardboard box and cut out the top and front sides of the box.
Place equal amounts of soil into the plant trays.
Next, place the plants into the trays and put the tray in the box. Tape plastic centimeter rulers along the back of the box, aligned with the tray.
Repeat steps 1-3 for three additional box and trays. After, label each box. (A, B, C, and D)
Measure the initial heights of each plant and record in the data table
Drill two holes 10 centimeters apart on the right and left sides of the boxes.
Prepare the tubing by drilling multiple small holes along the tubing.
Place tubing across the boxes into the drilled holes.
Attach metal clamps on each end of the tubing to prevent the water or air from entering or leaving.
Using the plastic wrap, cover the two open sides of each box as tightly as possible to prevent outside air from entering.
Drill holes into the plastic wrap only for one box labeled D, which is the control.
Place each box in an area where adequate sunlight and room temperature can be obtained.
Water each box by using the plastic tubing with 300 ml of filter water.
For the three experimental groups, add different volumes of CO2 from the tank by using different size balloons. For box A, add four balloons full of CO2. For box B, add two balloons full of CO2. Finally for box C, add one balloon full of CO2.
Place the opening of the balloon carefully on the tubing to allow the CO2 to enter each box.
Measure the height of each plant in centimeters every other day and record.
Repeat step thirteen to sixteen for ten days.

6. Data Plant 1 Plant 2 Plant 3 Plant 4 Plant 5 Plant 6 Plant 7 Plant 8
Box 1
3000 ppm 31 25 32 26 20 27 18 17
Box 2
1500 ppm
36cm
18cm
33cm
20cm
30 cm
27in
31cm
Box 3
750 ppm
22cm
16cm
24cm 21 19 23
Box 4
Regular air
15cm
17cm
14cm
23cm

7. Averaged Data
Box 1
Box 2
Box 3
Box 4
16.33 cm
22 cm
16.5 cm
15.33 cm

8. Statistical Analysis

9. Photo Documentation. Me watering a group of plants
Me with one group plants at the end of the experiment
Me watering a group of plants

10. ANOVA Results
The ANOVA test shows that the results were not significant. Thus, the results could have occurred due to chance. The p value was > .05

11. Conclusion Carbon dioxide accelerated plants’ growth.
However, the plants receiving the highest amount (3000 ppm) died.
This may be due to the toxic side-effect of very high level of carbon dioxide.

12. Potential Sources of Error
Inadequate sunlight- sunlight occurred in the same spot only for a few hours
Could have used lights instead
The seeds could have been bad
Could have planted seeds first and used the ones that grew well to grow with the CO2
CO2 delivery
Could have been delivered more accurately using a carbon dioxide scale

13. Extensions Test experiment with different plants
Test experiment again more precisely with higher amounts of Carbon Dioxide
The effect of sunlight on plant growth
The effect of temperature on plant growth

14. Applications Is used by green houses to increase plant growth
Could influence more people to growth more plants using a high concentration to maximize growth in a shorter period of time.

15. Acknowledgements Parents Ms. Pietrangelo
People who accept this experiment