PURPOSE
The purpose of this experiment was to compare the effect of
“cool white” versus “plant and aquarium” fluorescent light bulbs on the biomass
and height of soybean plants.
I became interested in this idea when I was at my friend’s house. I noticed that her mother had plants everywhere. They were grown under many different lights. I wondered if the different lights affected the growth of the plants.
The information gained from this experiment could help indoor gardeners by showing which type of lights to use to have their plants grow faster and bigger.
HYPOTHESIS
My first hypothesis was that the soybean plants would grow
taller under the “plant and aquarium” light.
My second hypothesis was that the soybean plants would have more biomass when grown under the “plant and aquarium” light.
I based my hypothesis on a statement from the General Electric Corporation website www.ge.com. They said the plant and aquarium florescent bulb is “specially designed to promote growth and flowering of plants, so they look healthier and greener.”
The constants in this study were:
• Amount of soil
• Amount of water
• Room temp (21degrees C.)
• Amount of light (16 hours a day)
• The kind of pea plant
• Wattage of bulbs (40 watts)
• Planting depths
The manipulated variable was the type of fluorescent light bulbs used.
The responding variables were the growth of the soybean plant in height and biomass.
To measure the responding variables, I used a metric ruler for height and a triple beam balance for the biomass and a ruler that goes up to 30 centimeters for the height.
MATERIALS
QUANTITY
|
ITEM DESCRIPTION
|
1
|
Ruler (that goes up to 30 centimeters
|
1
|
Spray bottle
|
1
|
Triple beam balance
|
1
|
48 inch (122cm) “cool light” fluorescent light bulb
|
1
|
48inch (122cm) “plant and aquarium” fluorescent light
|
144
|
Soybeans
|
2
|
Easy grow greenhouse (72 plants)
|
2
|
Fluorescent lights (bulb holders)
|
PROCEDURES
1. Gather all the materials
2. Plant seeds
a. Put equal amount of soil in each of the 72 cells in a planting
tray
b. Poke hole 1cm into soil in center of cell using a pencil point
c. Place 1 seed in each hole and cover
d. Water each cell using enough well
water to completely soak the soil
e. Drain the excess water
3. Set up lights
a. Position light one 30cm above soil, centered over tray one
b. Position light two 30cm above tray two
c. Set light timer to turn on 16 hrs/day
4. Every three days water the plants again by soaking the soil equally
5. Then drain excess water
6. Allow plants to grow for 6 weeks
7. Measure growth
a. Use cm. Ruler to determine average height of plants in each cup
b. Use a triple beam balance to find mass of all plants in each
group, after plucking out by the roots and removing
soil
8. Compare the results of the “plant aquarium” and “cool white” lights
9. Get rid of the plants (throw the plants in the compost or in the trash can)
RESULTS
The original purpose of this experiment was to compare the effect of “cool white” versus “plant and aquarium” fluorescent light bulbs on the biomass and height of soybean plants.
The results of the experiment were that the “cool white” light’s average soybean mass was more then the “plant and aquarium” light’s. On the other hand, the soybeans grown under the “plant and aquarium” grew taller (28.1 cm) than the “cool white” light (22.5 cm.)
CONCLUSION
My first hypothesis was that the soybean plants would grow taller under the “plant and aquarium” light.
The results indicate that my first
hypothesis should be accepted, because the height for the “plant and aquarium”
was 28.1 centimeters and the height for “cool white” was 22.5
centimeters.
My second hypothesis was that the
soybean plants would have more biomass when grown under the “plant and
aquarium” light.
The results indicate that my second
hypothesis should be rejected, because the biomass of the “plant and aquarium”
light was 1.0 grams and the biomass for “cool white” light was 1.2 grams.
After thinking about the results of
this experiment, I wonder if using more varieties of soils would affect the
growth. I also wonder if different brands of plant lights would produce
similar results to the GE lights used in this experiment. It would also be interesting
to compare the growth of soybeans in sunlight to those grown under fluorescent
lights.
If I were to conduct this project again, I would grow the plants for a longer time. I’d use many more plants, grown in more soil, and in bigger trays. That way each plant could have enough soil and room. I’d also use much more light, so that the plants would grow better.
If I were to conduct this project again, I would grow the plants for a longer time. I’d use many more plants, grown in more soil, and in bigger trays. That way each plant could have enough soil and room. I’d also use much more light, so that the plants would grow better.
Researched by ---- Tanairi L
