The Effects of Carbon Dioxide on Collard Seeds Lab Report

Introduction:

We knew that plants intake carbon dioxide, which got us wondering. Would an increased amount of carbon dioxide affect the plants (collards) at all? So we chose to test that as our experiment. We decided the easiest way to give more carbon dioxide was through dry ice. So, Teo voluntarily went out to Smart and Final and got dry ice. Our experimental group was the group exposed to CO2 and our control group was exposed to the air of the classroom.

Our source of Co2, dry ice.

Purpose:
The purpose of our experiment was to test the effects of increased carbon dioxide on collards growth in number of sprouts using dry ice.
Hypothesis:
If the number of collards grown is affected by increased levels of carbon dioxide, then the collards grown in increased carbon dioxide will have more sprouts, because the extra carbon dioxide will provide a fast and efficient way for plants to get the carbon dioxide they need, and change it into oxygen, causing faster growth.

Methods:

Materials:

1st Trial- 2 paper towels

              2 giant Ziploc bags

              2 small Ziploc bags

              2 plastic goldfish bowls

              10 control group seeds

              10 experimental group seeds

              1 styrofoam cup

              approx. 52 grams of dry ice

              water

2nd Trial- 2 72-cell trays

               soil

               2 giant Ziploc bags                                                              

               72 control seeds

               72 experimental seeds

               3 styrofoam cups

               157 grams of dry ice

               water

Procedure:

1st Trial-

1. Place 10 seeds each in a wet paper towel (about 5 mLs of water).

2.  Place each paper towel in a small ziploc bag.

3.  Place each small bag into a plastic fishbowl, and finally into a large plastic bag.

4. Repeat

5. Chip off approximately 52 grams of dry ice from a larger block ( we used a ten pound block) and place quickly in a styrofoam cup.

6. Place the dry ice in one of the bags.

7. Seal both of the bags.

8. Check the seed status after four days.  

                                                                           

2nd Trial-

1. Take two 72-cell planter trays and fill them with soil.

2. Fill each division with one seed, and water thoroughly.

3. Place each tray inside a large ziploc bag, such as the ones used in the previous trial.

4. Chip off approximately 157 grams of dry ice ( we used a 5-pound block) and place it in a styrofoam cup.

5. Place the cup in one of the bags ( the experimental group) and seal both bags.

6. Check after four days.

Results and Data Analysis:

Number of Sprouts Data Table

	8/29/14	9/2/14	9/4/14	9/8/14	9/11/14
1st experiment Experimental Co2 Group	0 sprouts (plant seeds)	0 sprouts	3 sprouts (exposed to air since 9/2)	- (dead sprouts)	-
1st experiment Control Group	0 sprouts (plant seeds)	5/10 sprouts	8 sprouts	- (dead sprouts)	-
2nd experiment Experimental Co2 Group	-	-	0 sprouts (plant seeds)	0/72 sprouts	11/72 sprouts (exposed to air since 9/8)
2nd experiment Control Group	-	-	0 sprouts (plant seeds)	56/72 sprouts	59/72 sprouts

This data table shows the exact days data was collected and the number of sprouts each day, for each experiment.

Seed Sprouts Graphs

In our preliminary experiment, we used approx. 52 grams of dry ice. Out of the 10 seeds in the bags, no seeds sprouted in the experimental group and only half sprouted in the regular oxygen group. In our actual experiment, with 72 seeds in each group, no seeds sprouted in the experimental group, and 56 seeds sprouted in the regular oxygen group. These bar graphs correctly represent the results, as it compares the info quickly and easily since there are only two variables. We believe that oxygen is necessary for the plants to grow because it is necessary for all living beings in order to carry necessary metabolic activity (a chemical process which helps living things grow, produce energy, etc).

Conclusions:

Our results showed that, countering our hypothesis, increased CO2 did not help plant growth, it instead stunted growth. With each experiment, the plants with only CO2 did not grow at all, until days later when they had been exposed to open air and oxygen. After doing further research on the subject, we found out that even though there is logic to our idea of increased CO2 as increased “plant food”, too much of a good thing isn’t always good. It is possible to increase plant growth using CO2, but is a delicate process that requires controlled amounts of carbon dioxide. One of the things that affected our collards was the heat of CO2 taking away from the water in the soil, as well as the nutrients. CO2 isn’t the only thing plants need, and isolating that factor decreased levels of other factors that go into plant growth. Further research also shows that too high of a C02 concentration can cause a reduction in photosynthesis.in some plants, as well as even decrease the nutritional value. Future experiments on CO2 and plant growth could show even more data. If we were to do another experiment, we would start with having plants with leaves already, as opposed to seeds, so that the leaves themselves could take in the carbon dioxide. Also, the CO2 would be in a more controlled amount and less, with more airflow instead of a closed off space.