The Effect of Household Soaps and Detergents on the Growth of Wheat

Researched by Kristi T.


The purpose of this experiment was to determine the effect of various household cleaners and detergents on the growth of wheat.

I became interested in this idea when I read a book about wheat in the school library. It said that wheat is the world’s most important and widely grown crop. I also decided to use soaps and detergents because I knew that they are widely used yet harmful to most plants.  

The information gained from this experiment would help farmers know whether detergents and soaps actually are harmful to their crops.  


My hypothesis was that laundry detergents would slow the growth of wheat more than any other cleaner.  

I based my hypothesis on a statement that Karen Logan made. She wrote an article on an Internet site (http://WWW. geocities. com/rosemarygarden/chemfaq.html), called “Clean House Clean Planet”, about soaps and detergents. In the article she said “There are many chemicals in detergents that can harm plants. “This made me think that they would be more harmful to plants than just normal soaps.

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The constants in this study were: 

  • Pot size/shape 
  • Seed age/ storage 
  • Soil moisture
  • Amount of soil
  • Soil brand
  • Amount of chemicals 
  • Amount of time until measured after adding cleaning products
  • Amount of time to grow
  • Temperature 
  • Place
  • Species of wheat
  • Planting depth
  • Where water comes from
  • Procedure
The manipulated variable was the cleaners and detergents used on the wheat.  

The responding variable was the height of the wheat.  

To measure the responding variable I used a ruler calibrated in millimeters.



4 Tin pans
34 millimeters wheat seeds
1 Meter sticks
100 millileters water every third day
4200 millileters potting soil
3 different cleaning chemicals
3 yards string
1 Permanent marker

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1. Planting
  A. Put 600 milliliters of soil in the bottom of each pot
B. Sprinkle 17 milliliters wheat seeds onto soil
C. Add 300 milliliters of soil in the pot around the plant
  D. Add 100milliliters of water every third day during the whole experiment
  E. Wait seven days and then start step number two 
2. Measuring Chemicals
2. 5-make sure you label the pots (put the name of a different chemical on each) (label one control)
A. Measure 5milliliters of each of the chemicals 
B. Add only 95 milliliters of water to this
C. Pour one solution into each of the three trays except the control
D. Let this sit for 30 days
3. Making a Grid
A. Use the meter stick to measure every 5 centimeters and mark it with a permanent marker on the side of the tray
B. Tape string on each of the marks so that it stretches across to the mark across from it
  4. Measuring Plants
A. Measure a plant at every intersection in the string
B. You should have 10 measurements for each tray
  5. Comparing the Data 
A. Compare to see which group of plants was the tallest
B. Compare to see which group of plants was the shortest

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The original purpose of this experiment was to determine the affect of various household cleaners and detergents on the growth of wheat.

The results of the experiment were that bleach effected wheat plants the most. Its average height was 3. 56. Dishwasher detergent came in second with 3. 9 millimeters in height and laundry detergent came in third with 4. 35 millimeters in height.  

See my Data Table and Graph.

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My hypothesis was that laundry detergents would slow the growth of wheat more than any other cleaner.  

The results indicate that this hypothesis should be rejected because bleach slowed the growth the most. In fact, the group of plants that had laundry detergent put on them was the healthiest. Its average growth was 4. 35 millimeters. The average growth for dishwasher detergent was 3. 9 millimeters. The average growth for bleach was3. 56 millimeters.

Because of the results of this experiment, I wonder what would have happened if I had tested several different brands of bleach instead of using laundry detergent and dishwasher soap.  

If I were to conduct this project again I would try to keep track of time better than I did before. I lost track of time and had to redo my entire experiment. I would also conduct the experiment during a warmer time of year. If I had done this then I could have had the wheat grow under true sunlight instead of artificial light from light bulbs. I would have used more plants and pots, too.  

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Humans need plants to live. Without plants there would be less food, less water and no oxygen. Pollutants kill plants.  


“A plant is any of various organisms that manufacture their own food, cannot move under their own power, and have cells with walls made of cellulose. ”

Basically a plant is something that is living but that is not an animal. There are 260,000 different plant species. Various plants can grow almost any where in the world.


Plants do not really eat anything. They soak up water and minerals using their roots like small sponges. They then turn this into something similar to sugar in their leaves. This process is called photosynthesis.

“Photosynthesis is the chemical process by which plants that contain chlorophyll, especially green plants, use light to convert carbon dioxide and water to carbohydrates, releasing oxygen as a byproduct. ”

Basically photosynthesis is when plants use light to chemically change water and carbon dioxide to make their own food. The formula for this is (6 H20 + 6CO2=>C6H2O6 + 6 O2).  


Botanists are scientists who study plants. Usually they study things about plants like where they grow and how they grow.


Pollution is the contamination of air, water, or soil by harmful substances.

Water pollution comes from garbage dumps. Water pollution also comes from sewer systems, factory waste, and automotive waste. When people make garbage, usually, the garbage ends up, one way or another, in water. When small animals drink the contaminated water they become sick. Then when larger animals eat them they get sick too. Then when we eat the sick animals we get sick and sometimes die. Water pollution often leads to soil pollution.

Soil Pollution

Soil pollution comes from polluted water. When contaminated water gets into the clean soil the soil becomes contaminated too. This damages  plants and agricuture.


Wheat is the most important and widely grown crop in the world. Wheat is in almost everything that is baked today. Without wheat there could be no breads or things like that.


The main use for wheat is food for humans. Some humans use wheat in bread. Some humans use wheat in crackers. Some humans use wheat in treats. Wheat is used all the time, all around the world. Wheat  is in almost every meal baked or cooked in the world. Wheat is also in pasta.

An unripe field of wheat is a very, very rich green. A ripe field of wheat is a golden-brown. On the top of a ripe stalk of wheat there are small, packed wheat seeds.  


Without plants there would be less food, less water and no oxygen. Certain pollutants, like detergent and bleach, can kill plants. Humans need plants to live because we need water, food, and oxygen.

Acker, Duane. “Agriculture” World Book Encyclopedia. 1998

Barss, Karen. Clean Water. Chelsea House Publishers, 1992

Chertow, Marian. “Water Pollution”. World Book Encyclopedia. , 2002
Croy, Lavoy. “Wheat”. World Book Encyclopedia. , 1999

“Soil Pollution” ENCARTA Encyclopedia Deluxe, 2001

Feinstien, Myron E. Detergents and Soaps, 1998

Freeborn, Joel. “The Effect of Propylene Glycol on the Growth of Radishes”

Hershey, David R. Plant Biology selah schools, science project, SIS science, S.I.S.. John Wiley, 1995

Hoff, Mary. “Plant Diseases. ” 10/29/03
http://WWW. Elibrary. Bigchalk. COM

Logan, Karen “Clean House Clean Planet”
http://WWW. geocities. com/rosemarygarden/chemfaq.html

Mifflin, Houghton. “Photosynthesis” Student Dictionary.

Mifflin, Houghton. “Plants” Student Dictionary.

Mifflin, Houghton. Student “Wheat” Student Dictionary.

Pringle, Laurence. Oil Spills, Marrow Junior Books, 1995 

Taylor, Myca “The Effect of Portable vs. Gray Water on Radish Growth”

Wagner, David. Photosynthesis, 1998

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I would like to thank the following people for helping make my project possible:

  • My parents for pushing me to do my best
  • Mrs. Helms for helping me with my table and report
  • Mr. Newkirk for showing me the mistakes I made and helping me with almost everything


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