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Do Plants Grow Better in Water or Soil?

Researched by Andrea R.

The purpose of this experiment was to determine whether plants grow better in water or soil.
I became interested in this idea when I started my experiment last year, and looking through books for research.
The information gained from this experiment will help gardeners know how to grow their plants healthier, taller, and faster.

My hypotheses are that the vegetables will grow better in water, the flowers will grow better in soil, and the grass will grow equally well in both.
I base my hypothesis on the science books I got an idea from, because when I started my research all the books and encyclopedias said the same things about hydroponics. 

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The constants in this study were:
-Same kinds of seeds
-Same kind of water
-Same amount of water
-Same kind of cups
-Same size of cups
The manipulated variable was growing the plant in water or soil
The responding variable was the plant’s mass and total length.
To measure the responding variable I will measure the length in millimeters using a ruler, and the mass in milligrams using a triple beam balance.

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1 package
 Radish seeds
1 package Cucumber seeds

1 package 
Snapdragons seeds

1 package 
Batchler’s Button seeds
100 seeds Lawn grass seeds
  Plastic cups
  Spray Bottle
   Potting Soil

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1. First gather all materials to begin experiment
2. Then place soil in 5 cups about 5cm high with potting soil
3. place white purified sand in 5 other cups about cm high
4. next  place 5 radish seeds in one of the soil cups and 5 seeds In one of the sand cups, label them "radishes"
5. place 5 cucumber seeds in another cup filled with soil and 5 seeds in one of the sand-filled cups and label those two cups "cucumbers"
6. place 5 snapdragon seeds in one of the soil filled cups and 5 seeds in one of the soil-filled cups and label them "snapdragons"
7. place 50 grass seeds in one of the sand-filled cups and 5 seeds in one of the soil-filled cups label both of them "grass"
8. place 5 batchler’s bottens in the last soil-filled cup and 5more seeds in the last sand cup label them "batchler’s bottens"
9. after that carefully pour 200ml of water in the sand-filled cups trying not to stir up the seeds and sand
10. water  everyday the soil-filled plants  with 50ml a day
11. make sure that the hydroponics have 200ml of water all the time
12. record the plant growth for 5 weeks and record the data
13. on the 35th day pull the plants and get all the dirt off so it will be a more constant mass
14. measure the mass and length of the plants by a millimeter ruler, and the  mass with a triple beam balance 


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The original purpose of this experiment was to determine whether plants grew better in water or soil.
The results of the experiment were, radishes grew better in soil by  , cucumbers grew better in soil, grass grew in both but better in soil, bachelor's buttons grew better in soil, and snapdragons grew better in soil.
See the tables and graphs on next page.


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My hypotheses were that the vegetables will grow better in water, the flowers will grow better in soil, and the grass will grow equally well in both.
The results indicate that the vegetables didn't grow better in water so this part of the hypothesis should be rejected. The flowers grew better in soil so this hypothesis should be accepted. I thought the grass would grow equally well in both water and soil, but it grew much better in soil so my 3rd hypothesis should be rejected.
Because of the results of this experiment, I wonder if plants would grow equally well in soil and water with fertilizer.
If I were to conduct this project again I would grow a wider varity of plants to get a more accurate idea of which plants grow better in water or soil.

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Have you ever wondered if plants grow better in water or soil? Well in this experiment you will learn all about the plants, and what kind of habitat that they adapt to (live in water or soil). 
Water is one of the most important things to all living things, especially plants, because plants don't eat food like animals. Water is made out of two atoms of hydrogen and one atom of oxygen, when those three atoms combine you get a water molecule. That may not be much, but mix lots and you can get a glass full of water, and you can water lots of plants with one glass of water. Every living thing on earth needs water to survive, and they get water from many sources. You can get water from the ocean, lakes, streams, snow, glaciers, rain, hail, and more. 
Soil is one of the most important things to plants. Soil is made up of broken down rocks and minerals, eventually in about a century the soil will form. You just have to have the right climate, good land surface features, and a lot of time. The soil provides plants with special nutrients that help the plants grow faster and bigger. The soil also helps the plants grow in another way, it covers the roots. You may plant the seeds in the dirt, but then the stem grows up and out of the soil. But the plant would die if the roots were not covered.  Plants "eat" through their roots, so soil is one of the most important things to grow a plant.
Hydroponics is the artificial way to grow plants. It was developed in the 1860’s by the man named Julius Von Sachs. The theory of hydroponics became a scientific fact once other scientists proved it could be done. Hydroponics was a very good idea, but you had to put sand like grains in the bottom of the pot, so it can work like the soil, and help the roots. In the 1930’s people started to grow large crops hydroponicaly. Now the scientific method of hydroponics is used all around in experiments, and in crops.
Plants are grown all around the world, for food and decoration. This experiment involves radishes, green beans, grass, bachelors’ buttons, and snapdragons.  Green beans and radishes represent food plants and herb plants, the snapdragons and bachelors buttons are examples of flowers, and the grass is a common land covering.  Plants are an important part of the food chain, and humans couldn’t live if they didn’t have plants. Some people don’t have good soil, so they could grow plants in water. Using these plants wont show if all plants grow in water, but will tell about the majority of plants. 
In conclusion plants can now grow in water instead of soil, and still serve their purpose. 

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"Hydroponics," World Wide Encyclopedia, 1995
"Radishes," Academic American Encyclopedia, 1998
"Radishes," Encyclopedia America, 1999
"Radishes," World Wide Encyclopedia, 1999
Gardner, Robert, "Experimenting with Water"
"Soil," Cynthia Fujii, World Book Encyclopedia, 1995
Soil and Plants
Sally Morgan, Water
"Water," World Book Encyclopedia, 1999



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