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Science Project: How Does Salt Affect Seed Germination?

Updated on June 8, 2017
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VirginiaLynne is an educator and mom of 5. Her Science Fair articles are based on her experience helping her children do their projects.

Excellent for Junior or Senior High

This is the research plan my daughter used for her Junior High Project. She won first place at our Regional Contest and competed at State. She also won some special awards because she had tackled a real-world problem.

The reason this simple project did so well is that she was able to explain how important it is for farmers to be able to determine when the salt concentration in soil hurts the germination of plants.

Another child in our family did a variation of this project in 5th grade for her school project, so I know that this experiment also works with younger children, but be sure that your child has at least one to two weeks time for the experimental process.

Salinity and Crops Science

The amount of salt in soil is a major problem for growers.
The amount of salt in soil is a major problem for growers. | Source

Question

The question is what you are going to test. You can do this same experiment in many different ways. You can vary your question by changing:

  • The amount of salt in water.
  • The number of seeds you use.
  • The type of seeds you use.
  • How you grow the seeds.
  • Where you put the seeds to grow them.
  • What you use to grow the seeds on.

Sample question: How much teaspoons or portions of teaspoons, of salt dissolved in a cup of water, can be withstood by 100 germinating radish seeds if 1 tablespoon of the salt water in the cup is added at a time in a Ziplock Bag with a coffee filter to hold the water?

Hypothesis

Your hypothesis tells what you think the answer to your question will be. It is your guess. After doing your experiment, you will compare your guess with the results for your conclusion.

Sample hypothesis: The more salt in the water, the fewer seeds will germinate. The radish seeds will not germinate at all in a solution with more than 3 teaspoons of salt in 8 oz of water.

When soil has too much salt, crops won't grow well.  This experiment studies how salt affects seed germination.
When soil has too much salt, crops won't grow well. This experiment studies how salt affects seed germination. | Source

Materials

  1. 10 Ziplock Bags
  2. 1000 radish seeds
  3. 10 coffee filters
  4. tap water (tap water is the control)
  5. distilled water
  6. table salt
  7. teaspoon
  8. 10 cups
  9. 8 oz. measuring cup

Radish Seeds in Salt Water
Radish Seeds in Salt Water | Source
Radish Seeds Germinating in Bag
Radish Seeds Germinating in Bag | Source

Procedures

Take ten separate cups. Label them A through J. Fill them as follows:

  1. Solution A: 8 oz. tap water
  2. Solution B: 8 oz distilled water
  3. Solution C: 8 oz distilled water with ½ teaspoon of table salt. Stir to dissolve salt.
  4. Solution D: 8 oz. distilled water with 1 teaspoon of table salt. Stir to dissolve salt.
  5. Solution E. 8 oz. distilled water with 1 ½ teaspoons of table salt. Stir to dissolve salt.
  6. Solution F. 8 oz distilled water with 2 teaspoons of table salt. Stir to dissolve.
  7. Solution G. 8 oz. distilled water with 2 ½ teaspoons of table salt. Stir to dissolve.
  8. Solution H. 8 oz. distilled water with 3 teaspoons of table salt. Stir to dissolve.
  9. Solution I: 8 oz. distilled water with 3 ½ teaspoons of table salt. Stir to dissolve.
  10. Solution J: 8 oz. distilled water with 4 teaspoons of table salt. Stir to dissolve.

2. Place the 10 Ziplock Bags down on the counter at room temperature. Label the top and bottom of each plate with the letter of the solution to be used in each one (A through J).

3. Unzip the bags and put a coffee filter in each one.

4.. Pour one tablespoon of each solution onto the filter in the bag with the same label, making sure it soaks the whole coffee filter.

5. Divide the 1000 seeds into groups of 100. Put 100 seeds on the filter of each Bag. Make sure the seeds are scattered evenly over the filter.

6. Zip up the Bags. Place all 10 dishes at room temperature out of direct sunlight (seeds don't need light to germinate and light can cause fungus to grow).

7. Observe the dishes daily and record number of seeds that have germinated in each dish and any other changes in the seeds.

8. Record results in journal.

Safety

in truth, this experiment doesn't really require any particular safety procedures. However, if you are required to put this section on your board, you can include something like the following:

Sample Safety Procedures: You need goggles for the salt water splashing in your eyes, and gloves so you do not transfer bacteria to the seeds.

How Salt Accumulation Affects Crops

Farmers sometimes flood their fields to leech out the salt that accumulates.  That takes a lot of water.
Farmers sometimes flood their fields to leech out the salt that accumulates. That takes a lot of water. | Source

Results

As you conduct your experiment, you should record what happens every day on a chart. When your experiment is finished, you will look at the results and write out what happened. You can choose to talk about this in different ways:

  • Describe what happened day by day to each bag.
  • Describe the overall results and then talk about particularly interesting things that happened.
  • Talk about the results for each bag and then compare them.

Sample Table for Results

Solutions:
A: number sprouted
B: number sprouted
C: number sprouted
D: number sprouted
Day 1
 
 
 
 
Day 2
 
 
 
 
Day 3
 
 
 
 
Day 4
 
 
 
 

Conclusion

What do you think about your results? In your conclusion, you explain:

  1. Whether your guess was right or not.
  2. How your results compare to your hypothesis.
  3. Your ideas of why your results came out the way they did.
  4. How you would revise the experiment to make it better.
  5. What experiment would you do next to get more information?
  6. The importance of your experiment to real-world problems.

Abstract

An abstract is a short summary of everything in your experiment. It explains your procedures, your results, and your conclusion briefly. Scientists rely heavily on abstracts when they are researching. They will read the abstract to get an overview of that experiment and decide if they need to read the full article.

Sample Abstract of Experiment and Results: The problem was to determine the effect of salt water on germinating radish seeds, and also to determine if there was a maximum concentration that could be tolerated.

To do this, coffee filters were wet with 1 tablespoon of salt water from cups that increased in concentration by 1/2 teaspoon of salt in each cup of 8 oz. of water. The filters were then placed in the plastic bags. The 50 seeds were then placed on top of the coffee filters, inside the bag. The seeds that germinated were counted and charted. Tap and distilled water without salt were used as controls.

The results were that the germination was 100% with the controls, tap and distilled water. On the groups exposed to salt water, the germination decreased as the salt concentration increased, and no germination occurred at amounts of 1.5 tsp. of salt or higher. This supported the hypothesis, which was, "The more salt in the water, the fewer seeds will germinate."

This information could help gardeners and farmers to know when saline reaches dangerous levels for radish seeds.

Experiment Tips

Start early: It is always a good idea to start your experiment early so that you have time to re-do it if you have any problems. Two of my children did versions of this experiment for our state science fair. Maggie, who did the experiment first, found that none of her seeds germinated! Luckily, she had started her experiment early enough that she had to time revise her procedures, adding less salt in the water, and re-do her experiment.

Tell the Whole Story: In her conclusion and results, Maggie wrote the whole story of her experiment, the original failure, and her second try, which is exactly what my husband does when his experiments don't work the first time!

Be honest: Scientists are always honest about their results. If your experiment doesn't work out but you did everything you said you would do, and you don't have time to revise and do it again, you should still publish your results exactly. What you can put in your conclusion is how you would alter the experiment next time.

Variations

Plants not seeds: You can do a variation on this project by watering plants with water with different concentrations of salt to see how salt water affects the growth of plants. As the coordinator of an elementary science fair, I've seen students do lots of plant watering experiments using different kinds of water, or liquids other than water. but I've never seen a salt experiment.

Different types of seeds: Radish seeds sprout quickly, but many other types of crop seeds could work as well.

Plant the seeds: You could do a longer variation of this project by planting some of the seeds that sprout and continuing to water them with the same salt concentration.


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    • VirginiaLynne profile image
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      Virginia Kearney 6 weeks ago from United States

      Hi Vilda, you probably ought to allow at least 2 weeks for this project, although you might get enough results earlier, depending on how fast the seeds germinate.

    • profile image

      Vilda 6 weeks ago

      Hi! This is a very interesting project. I am wondering how long time it took in total, from the seeding until finished.

    • VirginiaLynne profile image
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      Virginia Kearney 8 weeks ago from United States

      Hi, Amber--Yes, oz. means fluid ounces.

    • profile image

      Amber 8 weeks ago

      When you say oz. do you mean fluid ounces?

    • VirginiaLynne profile image
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      Virginia Kearney 2 months ago from United States

      Hi Amber--that is a very good question. If the seeds are too wet, they can develop mold and that will mean you will have to start the project over again.

    • profile image

      Amber 2 months ago

      Why should the seeds be kept damp and not wet?

    • VirginiaLynne profile image
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      Virginia Kearney 4 months ago from United States

      Hi Brianna! This is an easy experiment to do that is actually about a very important problem that we need to solve. I hope you enjoy doing this and learn something about the environment and how we need to protect it.

    • profile image

      Brianna Brown 4 months ago

      I was looking all over for a project like this one. I never new that I was going to find it I love it thank you!!!

    • VirginiaLynne profile image
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      Virginia Kearney 3 years ago from United States

      Glad you like it Chelsea. One of my younger daughters just did a version of this one for her science fair project in 6th grade. It is easy but has a very important point. Right now in California they have a terrible drought. One of the problems with the fields in California is that they have a lot of salt in them. One of the ways they get rid of the salt is to flood the fields with water to let the salt leech out. Of course they can't do that when they don't get enough water. So finding out about how salt inhibits germination and growth is important.

    • profile image

      chelsea 3 years ago

      I love this experiment

    • VirginiaLynne profile image
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      Virginia Kearney 3 years ago from United States

      Aaliyah--I'm not sure what you mean by dependent and independent variables. The variable in this project is the amount of salt in the water. Everything else is constant. The plain tap water is the control.

    • profile image

      Aaliyah 3 years ago

      Please tell me what are the dependent and independent variables

    • VirginiaLynne profile image
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      Virginia Kearney 3 years ago from United States

      Ladruzzi--Check the filters daily. Only add water if they are getting dry. You want them damp and not wet. Two weeks is just about right.

    • profile image

      landruzzi 3 years ago

      Sounds like a great experiment. My question is, do we dampen the filters on a daily basis or skip a day? I wasn't sure how long you would continue this project as well. Is it about a two week time frame of observing the seeds? Thank You.

    • VirginiaLynne profile image
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      Virginia Kearney 3 years ago from United States

      Yash, If you are looking for an easy way to do it, you might want to have several bar graphs representing the progression of days with the numbers of germinated seeds indicated by different bars under the different salt concentrations.

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      Yash 3 years ago

      Can you help me make a rough graph of seed germinated vs. salt conc. ?

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      That 4 years ago

      Awesome I'm so doing this

    • VirginiaLynne profile image
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      Virginia Kearney 5 years ago from United States

      Nova--thanks so much for telling me! I will pass this along to my daughter, she will be excited to hear about it. My son had his science fair at region yesterday and won first in his category--he gets to go on to state again now. I'm so glad that we have competitions which keep kids interested in science!

    • profile image

      Nova 5 years ago

      Hi,

      My daughter did the experiment about salt n seeds ,she followed some of your ideas and she won first place in her science fair this yr in 2nd grd. Thank you so much, keep posting such inspiring experiments.good job.

    • VirginiaLynne profile image
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      Virginia Kearney 5 years ago from United States

      Great! I'd love to have you come back and share how it worked for you. My daughter got 1st place in her regional for this project and also went to state.

    • learnlovelive profile image

      learnlovelive 5 years ago from U.S.

      No problem, Virginia. I want to thank you for being so professional in your demonstration. The scientific method is so important, people don't even understand. And, "You Rock!" was both a pun and a double entendre. Your Hub was about salt, hence the rock pun and you posted a comment about the effects of music on plants. This is awesome, hence the part about you rocking...and you were actually talking about rocking out with the plants. That rocks, quite literally. Keep up the good work, your approach is well-appreciated and you are good at demonstrating thorough processes.

    • VirginiaLynne profile image
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      Virginia Kearney 5 years ago from United States

      Thanks for stoping by learnlovelive! Hey keithlinpke--I've seen that one too! Or an experiment where people put some plants in a room with rock music, and other plants with classical. Interesting!

    • keithlipke profile image

      keithlipke 5 years ago from Fort Wayne, Indiana

      My science project was talking to plants :)

    • learnlovelive profile image

      learnlovelive 5 years ago from U.S.

      Awesome. You rock.

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