CAVE GROWING


This is our lab group!
From the back left there is Maggie and Chelsea, in the front starting on the left is Alyssa and Sarah.

Introduction

Link to our abstract page:

 Abstract

Purpose: For our experiment we were to find the least amount of light needed to grow healthy corn plants, so plants could be grown in a cave with minimum electricity on a deserted island.

Hypothesis: If we set up four experiments, where each situation is recieving different amounts of light and in different intervals, then we will be able to discover the minimum amount of light needed.  We believe that 12 hours of light would be most effective with the most growth.

Background Information: For our backgound information we researched light intensity, light requirements, types of light used to grow plants, and photosynthesis.   We learnred that every plant has certain requirments they need to be grow, produce energy and to live.  We learned they need sunlight, water, energy from food produced by photosynthesis, and chlorophyll.  By researching light intensity needed for good plant growth we discovered that 6 hours is needed at the least for a plant to grow and be healthy.  Since for our project we couldn't use actual sunlight we had to learn what type of light we could use for the seeds to grow.  After researching we learned that when growing a garden using artificial light different types of bulbs.  Though for small seedlings or a small number of plants flourescent lights are suitable.  Since our seeds were corn we researched the light needed for growing vegetables.  These types of lights are metal halide lights.

Procedure

Equipment Used:
 

1. Three Timers 6. Water (you need to water your pots daily)
2. Five light Sources 7. Cardboard (so you can surround your pots, and make a dark enviroment like a cave)
3. Eight Pots 8. Ruler (to measure your plants for data)
4. Soil 9. Journal (to record daily findings of your experiment)
5. Seeds (around 40 seeds/ 5 in each pot)

Steps to Set Up Experiment:

1. Moisten the soil by adding some water to it then mixing, but make sure it is not wet but yet it is damp.
2. Put soil in pots so that the pots are 3/4 full.  The pots should be at least 4 inchs in diameter.
3. Plant 4-5 seeds in each of the eight pots.  Make sure the seeds are at least 1 inch down under the soil and 4-6 inchs apart.
4. Set one timer for 4 hours, one for 8 hours, one for 12 hours, and we had one experiment where there was no light to prove light was needed.
5. Plug timers into three light sources.
6. Put two pots under each of the light experiments.
7. Around all the plants and the lights place cardboard so that no light is able to enter in and effect the plants growth.
8. Water the plants if needed.
9. Check and record your plants results daily.
10. Water whenever needed throughout experiment.

Results
 
 

Plant Growth Status
11/1/99
12 hour light  8 hour light 4 hour light No Light
Plant #1 4 cm 5 cm 6 cm no growth
Plant #2 3 cm 4 cm 4 cm 1 cm
Plant Growth Status 
 11/9/99
12 hour light 8 hour light 4 hour light No Light
Plant #1 8 cm 10.5 cm 21.5 cm no growth 
Plant #2 10.5 cm 10 cm 12 cm 1.5 cm

 
Plant Growth Status
12/1/99
                  All our plants have died.  This is due to lack of water over a long weekend and an over abundance of light.

Links to see results:

Graph of all data
Graph comparing 4 conditions

Picture

Journal Entries

Conclusion

    Our group has concluded that and over abundence of light can kill plants as well as not consistently watering the plants, for they need to stay moist and healthy.  We have concluded that four hour light daily was an extremely good amount of time for the plant to grow with the least amount of light possible, we had the most amount of growth in the pots under the four hour light.

Was our hypothesis correct?

    Our hypothesis, which we stated in the begining of the lab report ended up being wrong.  We said that the twelve hours of light a day would be the most effective, when in fact four hours of light was the best for the growth of plants.  The twelve hours of light was too much we believe now and it dried out the roots.

What did we learn while experimenting with cave growing?

    While we were doing our experiment we learned how to care for plants.  We chose this project because we had come up with ideas previous to begining our experiment that we wanted to try out, and to see if we were right in our hypothesis!  We also learned that light does have a major effect on the growth of plants.  (and if you keep the light on for 24 hours straight over the weekend we also learned that it will kill your plants)