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
The constants in this study are:
Amount of water.
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.
| alfalfa seeds|
|11x11 paper towels|
|scale (capable of measuring to 1 gram)|
|roll of tape|
- 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.
- Take one glass and put 250 ml. of water and mix in 15 grams of salt.
- Take another glass and add 250 ml. of water and mix in 15 grams of
- Take another glass and pour 250 ml. of water in.
- 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.
- Repeat step five two more times using identical methods.
- 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.
- Using the same method as number seven, put the next towel in the sugar
water. Label it sugar.
- Using the same method as number seven, put the last rolled towel in
the plain water. Label it controlled.
- Donít disturb the alfalfa seeds for a week, but replace the
appropriate liquid if a glass starts to run dry.
- 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.
- 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
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,
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.