The Effect of Salt and Sugar on Alfalfa Seeds

Created by Naomi L.

6th grade SOAR 1998



The purpose of this experiment was to determine what substances, like salt and sugar, when dissolved in water, will affect the growth of alfalfa seeds. I hope to see which substances have the greatest effect.

 I became interested in this idea because I am concerned about pollution and how it affects plants. I know salt is used to melt ice on winter roads. I was concerned it might create an environmental problem.

 The information gained from this experiment will help people make better decisions about substances that are safe or dangerous to use near plants. Farmers and homeowners would be especially interested in my results.




My hypothesis is that plain water will sprout seeds better than either salt or sugar solutions. The mass of the sprouts in plain water will be greater than the mass of the sprouts, in the salt or sugar solution.

I base my hypothesis on the information that I have collected from a book from which I have used during this experiment. Focus on Life Science said, "Plants do not grow when other substances are absorbed in the plant."




The constants in this study are:

Amount of water.

Amount sunlight.

The temperature of the seeds and sprouting areas.

The size and type of paper towel.

The amount of sugar or salt dissolved in the units.

The manipulated variable was the substance dissolved in each treatment.

 The responding variable was the mass of the sprouts.

 The responding variable was measured by weighing the dry sprouts on a spring scale capable of measuring in grams.








  45 grams

 alfalfa seeds


11x11 paper towels


identical glasses

 750 ml.

of water

 15 grams

of salt

 15 grams

of sugar


scale (capable of measuring to 1 gram)


roll of tape





  1. Get the following supplies:

    - 45 grams of alfalfa seeds.

    - 6, 11x11 paper towels.

    - 3 identical glasses. (Capable of holding 250 ml. or more.)

    - 750 ml. of water.

    - 15 grams of salt.

    - 15 grams of sugar.

  2. Take one glass and put 250 ml. of water and mix in 15 grams of salt.
  3. Take another glass and add 250 ml. of water and mix in 15 grams of sugar in.
  4. Take another glass and pour 250 ml. of water in.
  5. Now take one paper towel and evenly spread 15 grams of alfalfa seeds in a line across the center from left to right. Put another paper towel on top of the first one. Roll the towels tightly, so the seeds are sandwiched between them halfway between the top and bottom. Tape them together.
  6. Repeat step five two more times using identical methods.
  7. Now take one of the rolled up towels and stand it in the salt water, so the seeds are above the liquid. Label it salt. Let the liquid wick up into the towel and seeds.
  8. Using the same method as number seven, put the next towel in the sugar water. Label it sugar.
  9. Using the same method as number seven, put the last rolled towel in the plain water. Label it controlled.
  10. Donít disturb the alfalfa seeds for a week, but replace the appropriate liquid if a glass starts to run dry.
  11. After the week remove all seeds and sprouts from one group. Squeeze the paper towel and drain out the excess liquid. Weigh the alfalfa seeds and sprouts and record their mass in grams.
  12. Repeat step eleven for each of the three groups being careful to label the data to show what group it was from.





My science project is about testing alfalfa seeds sprouted with plain water, salt water, and sugar water. While I do this project I hope to learn more about plants and how they sprout.


Water gets to a plant by the epidermal cells of the roots. Root cells increase the amount of water that may be absorbed through the soil. Water entering the roots of a plant goes through xylem tissue up the plant to the leaves. As water leaves the xylem and goes to the leaf cells, more water must enter the roots to take its place. Water passes through the epidermal cells of the roots, through neighboring cells, and on into xylem cells in the center of the root. There is a flow of water that keeps on going up the plant from the roots, through the stem and out to the leaves, it is then evaporated and then somehow the water has to be replaced at the root if the plant is to live.


The first stage of growth in a seed is germinating. But first, before it can germinate, the seed absorbs water from the soil. It also needs oxygen and the right temperature. Many ripe seeds will not germinate at first even if they are under these conditions. These kinds of seeds are called "dormant seeds". Seeds become dormant so they donít start to grow at times when conditions are unfavorable, or when they would usually not survive. Times of drought are not ideal for plants to sprout.


All plants have special needs such as light, heat, humidity, water and soil. Although most houseplants are sold already potted, some of them can be grown from seeds or leaf cuttings from another plant. Plants that already potted are left alone until the roots have grown too large to fit in the container. Some houseplants live all year round, however some plants grow for just one season. Some plants only grow in certain soils, because most plants get a lot of their food and nutrients from soil, and some soils donít have enough food and nutrients for that specific plant. 


The root of a plant functions to anchor the plant to the soil and to absorb and transport nutrients and water, and sometimes to store food. The root also takes in minerals. The roots help transport these substances to the leafy shoots. Some roots also store food for later use. Root systems might be made up of one major root, called a taproot. Or the root system could consist of many taproots. Some plants do not have roots, stems, and leaves. These plants do not have the tube-like structures needed to move water. These plants are called "nonvascular plants. " Mosses, liverworts, and some algae are a part of this group of plants.


The root is a very important part of the plant because the plant needs water, nutrients, and minerals and the root takes in all these things. Many of the plants that we keep and own are houseplants. Houseplants are plants that are adapted to the habitat of peopleís homes. Most plants do not eat other plants or animals for their food; they produce their own food. Plants have been making food by a process called Photosynthesis. Photosynthesis in green plants makes use of two simple ingredients, water and carbon dioxide. Both ingredients make up large quantities on the earth. Water is taken into the plant through roots by osmosis and is carried through the stems to the leaves. Once the water reaches the leaves it moves into the cells by osmosis and is carried through the photosynthetic process.

There are many types of plants and they all have different reactions to different things. Some plants do not have roots, stems, and leaves. These plants do not have the tube-like structures needed to move water these plants are called nonvascular plants. Mosses, liver warts, and some algae are apart of this group of plants.




The original purpose of was to determine what substances, like salt and sugar, when dissolved in water, will effect the growth of alfalfa seeds.

The results of the experiment were that the plain water worked the best to sprout seeds. The sugar water worked better than the salt water, but not as good as the plain water. The seeds that were in the salt water didnít sprout at all. The seeds that were in the sugar water sprouted, but they didnít sprout as much as the seeds in the plain water.




 My hypothesis was that the seeds in the plain water would do better than the seeds in the salt and sugar water.

 The results indicate that this hypothesis should be accepted. The mass of the sprouts in the plain water was greater than the sprouts and seeds in the salt and sugar water.

 Because of the results of this experiment, I wonder if we should stop using salt to melt the snow and ice off the road, because it is unhealthy for plants

 If I were to conduct this project again I would have used a different product to wrap the seeds in, because it was hard to scrape the seeds off of the paper towels. I would also conduct the experiment 4 or 5 times to see if my science experiment is really accurate, use other amounts of sugar and salt (like 5 and 15 grams.) And I would also use different substances to put in the water.





Bates, Dr. Jeffery ."Hands on Science: Seeds to Plants", Belgium, Aladdin Books, 1991.

Burnie,  David .Eyewitness Books: Plant, New York, Knopf, 1989.

Carter,  Joseph L. Life Science: A Problem Solving Approach, Lexington, Massachusetts, Ginn and Company, 1971

Heilmer,  Charles H. Focus on Life Science, Columbus, Ohio, Charles E. Merrill Publishing Company, 1969.

Heimler, Daniel, and Lockard, Focus on Life Science, Columbus, Ohio, Charles E. Merrill Publishing Company, 1984.

"House Plants" Grolier Multimedia Encyclopedia, 1998.

"House Plants", The New Book of Popular Science, 1989, 4.