2644 - CSUN ScholarWorks - California State University, Northridge

22 · Journal of Student Research Abstracts
2684
THE EFFECT OF WATER CONTENT IN SOILS ON PLANT GROWTH.
Lauren Aguas and Steve DeGusta (teacher). John F. Kennedy High School, 6715 Gloria Drive, Sacramento,
CA 95831.
Every soil consists of minerals, water, air and organic matter. The amounts of these ingredients differ in the
various soils that make up the earth. With three soils: clay, peat and sand, I conducted, in my first experiment,
a test to determine the amount of water each soil contained naturally. I concluded that peat soil has the highest
water content. The second highest water content was in the clay soil. Also in my first experiment I conducted
a test that would determine the amount of water each soil is capable of absorbing. In order for a soil to
absorb a sufficient ainount of water it must contain organic material, such as carbon and compost, along with
clay. When clay and organic matter are blended together, they have a great capacity for absorbing water and is
therefore a good soil for planting. The peat soil contained a blend of clay and organic matter, allowing it to
absorb the most water, more than the clay and sand soils. With this information I took the experiment one step
farther and planted Cowpea seeds in peat soil and clay soil, two soils which contained the most water and were
capable of also absorbing the most water. All plants need a soil rich in water because water is essential for all
living organisms. This is precisely the reason that the peat soil produced the tallest plants. The peat soil was
capable of absorbing more water, critical for a plant to grow, as well as naturally containing more water within
it then the clay soil. The peat soil produced plants with more height than the plants grown in the clay soil.
The experiment showed that peat soil was the best soil for planting. (p = 0.01)
2685
TRANSFERRING MEMORY FROM PRE-CONDITIONED PLANARIA TO
UNCONDITIONED PLANARIA.
Jamie Lim and Steve DeGusta (teacher). John F. Kennedy High School, 6715 Gloria Drive, Sacramento,
CA 95831.
The purpose of this study was to determine if preconditioned Dugesia dorotcephala planaria retained the
knowledge of unconditioned planada through consumption. A lighted y-maze was built consisting of three
transparent tunnels with a light bulb at each end. Six planada were individually placed in the maze and trained
to go towards a negative stimulus of the lighted tunnel by rewarding them with water. They were tested in 15
trials and found that the planada chose the dark tunnel more readily. My statistical analysis revealed that this
discrepancy had a probability of less than 0.001 (p = 0.001), indicating that the planaria did not choose randomly,
but preferentially towards the dark tunnel. These 6 planaria were then cut up and fed to a group of 16unconditioned
planaria, the "experimental" group. Then 6-unconditioned planaria were also cut up and fed to
a group of 16-unconditioned planaria, the "control" group. Each of the 16 planaria in both groups were trained
to go towards the lighted tunnel and tested. The "experimental" group approached the lighted tunnel 54% out
of the total 15 trials, about 31% higher than the "control" group's. My statistical analysis of the planaria's
choice to go towards the light or dark tunnel revealed a probability of less than 0.001 (p = 0.001), indicating
that the planaria were affected by the two different kinds of planaria each group ate. Therefore, the "experimental"
group retained the knowledge from the preconditioned planaria, indicating that planada were trainable
to go towards a negative stimulus of light if given at least 60 trials in the maze. More trials in the maze
gave the planaria more knowledge to learn from.