The Broccoli's Beginning (The Initial Experiment)

Introduction

For the Story of the Seed Project, our group was given a packet of Romanesco Broccoli seeds. We decided to test whether or not the volume of soil affected the a seedling's growth. To do so we planted our seeds in various pots all filled with different levels of soil.

Hypothesis:

Our hypothesis was if there was more soil in the pot, then the higher the plant would grow. We decided on this knowing that it would be very hard for any plant to grow in almost no soil, and knowing that if there was more soil in the pot, the more room the plants' roots to spread out. Also, having more soil would be most normal conditions, if the seed were planted in an actual garden bed.

Materials:

Before any experiment can begin, materials must be gathered. So, we got 10 square potting cups with drainage holes at the bottom, a packet of Romanesco broccoli seeds, potting soil, a small plastic beaker, water, a ruler, 10 plastic bags, and a pen for labeling.

Procedure:

1. Gather the plastic bags, the potting cups, and the pen. Before doing anything else, it is really important to label which cup will have which amount of soil. The potting cups will each be put inside an unsealed plastic bag. Then label the bag with the amount of soil going into each pot.
2.  For the control group, seeds will be planted in a potting cup along with 9 oz. of soil. These plants will be kept moist by being watered every 2-3 days with 50 mL of tap water. Once the water drains out, the plastic bag surrounding the pot will keep the water beneath the plant, ensuring that the plant will never dry. Each cup will have two seeds planted at 1/8th of an inch deep each.
3. For the variable group, eight seeds will all be planted in the same type of potting cup, each with a different amount soil. Each amount will vary by 2 oz. There will be eight different variable cups (2, 4, 6, 8, 10, 12, 14, and 16 oz). Each cup will have two seeds in it, all planted at 1/8th of an inch deep. These seeds will be kept moist with the same method as the control group. 
4. The plants will be left inside a classroom with enough light to act as the sun.
5. Every couple days, check the plants' progress and record data. The data will be how tall the pant grows above ground. Measure with a metric ruler in centimeters. 
6. Analyze all data and draw conclusions after nine days of observation.

Observations

September 2:    All seeds were planted and watered with 50 mL

September 4:    All plants showed no signs of growth

September 8:  - 2 oz: no growth

                      - 4 oz: 6.6 cm, 0.1 cm

                      - 6 oz: no growth

                      - 8 oz: 7.2 cm, 8.8 cm

                      - 10 oz: 9 cm, 4.7 cm

                      - 12 oz: 7.2 cm, 6.2 cm

                      - 14 oz: 6.2 cm, 9.1 cm

                      - 16 oz: 8.9 cm, 5.6 cm

                      - Controls: 7.7 cm, 7.9 cm, 6.2 cm, 6.5 cm

2 oz

4 oz

6 oz

8 oz

10oz

12 oz

14 oz

16 oz

Controls (9 oz)

All plants on September 8th 

 September 11:    -2 oz: 0.3 cm, 0 cm
                           - 4 oz: 10 cm, 1.5 cm
                           - 6 oz: no growth
                           - 8 oz: 9.9 cm, 10.6 cm
                           - 10 oz: 11.5 cm, 6.5 cm
                           - 12 oz: 10.5 cm, 8.5 cm
                           -14 oz: 8.7 cm, 12.5 cm
                           - 16 oz: 7.5 cm, 11.8 cm
                           - Controls: 8.6 cm, 8.8 cm, 10 cm, 10.1 cm

2 oz

4 oz

6 oz

8 oz

10 oz

12 oz

14 oz

16 oz

9 oz  (control)

9 oz  (control)

Data Analysis: After nine days of observations, 90% of the seeds germinated, and the data shows the graphed results of the plants' growth.

Conclusion 

     By observing the graph and all of the information that we collected our data didn't really support our hypothesis. Our hypothesis was the more soil in the pot more it would grow. This is half correct because our plants basically grew the same height even if it had only four ounces of soil. This brings up another question. How can a plant that has less soil grow to be the same height as the ones with more soil? We have come to the conclusion that the reason for this is because since the time a plant first emerges from the seed to when they die they are always growing upwards. This happens because plants need sun light to survive,  and sunlight it up. So in order for a plant to survive they have to grow as tall as they can to get to the light. Therefore when a plant is planted with less soil which makes it lower to the ground it is going to grow more just to reach the sun. That is why some of our plants with less soil are the same height as the ones with more.
     Unfortunately, every experiment is flawed. In this case, there were a few mistakes. This includes possibly over-watering the plants. By over-watering the plants, it could have caused them to not germinate.Another small flaw was that the plants were not able to be in sunlight during the experiment. This may have been another factor that caused the seeds not to grow to their full potential or germinate. These were possible flaws in the experiment.