How will sandy soils help plants grow?

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How will sandy soils help plants grow? Team
Bikini Bottom
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Questions How will sandy soils help plants
grow? Hypothesis We think that sand mixed in
the soil will help with plant growth because the
sun will reflect off the soil and bounce onto the
underneath side of the plant leaves and allow for
better photosynthesis to take place. Control
Variable Each jiffy pot/sand mixture was
watered the same as the class control
group. Independent Variable The seeds will be
planted in a mixture of sand and jiffy pot soil.
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• Experiment to Test Plant Growth
• Collect 15 milk cartons. Rinse and clean. Cut
  each milk carton 3 inches from the bottom.
• 2. Soak jiffy pot according to directions. Tear
  apart the jiffy pot pellet as much as possible.
• 3. Measure out ½ cup of sand.
• 4. Mix ½ cup measured sand with the jiffy pot
  pellet and place in the milk carton. Create 15
  milk cartons with jiffy pot/sand mixture.
• 5. Plant the seeds in the sand 1 in. deep.
• 6. Put by sunlight and water 2 tbs. per milk
  carton each day.

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Sandy Pansies Growth
Height (In centimeters)
Plant A
Weeks of Growth
5
Sandy Pansies Growth
Height (In centimeters)
Plant B
Weeks of Growth
6
Sandy Pansies Growth
Height (In centimeters)
Plant C
Weeks of Growth
7
Sandy Pansies Growth
Height (In centimeters)
Plant D
Weeks of Growth
8
Observations We saw in the first two weeks of
our experiment that there was no plant growth.
After that we can see that the plants made
progress every week and that some plants had big
growth improvements. We observed that when
compared to other group experiments or to the
control group that our plant leaves had more of a
lime green/yellowish color, rather than a grass
green color. Our plant leaves were larger in
size than the control group leaves, although our
plant stems were shorter. Conclusions We
believe our hypothesis is true. Due to the
sand/soil mixture our plants grew better than the
control group. They grew differently than the
control group, but our leaves were larger and the
color was more interesting. We conclude this
happened because the sand reflected off the plant
leaves, causing the leaves to grow larger. The
larger leaves were able to soak up more sunlight
for photosynthesis to take place. This increased
the plants sugar production for food, allowing it
to grow fatter leaves.

Retest If we had the
opportunity to do the experiment again we would
use less sand and not pack the sand down so hard
inside the milk cartons. We would cut the milk
cartons down shorter so the milk carton would not
create a shadow across the plant.