Science Buddies: "Ask an Expert"

Good morning,

My daughter is doing her 8th grade science fair project, her topic question had to be turned in today. Her original project which she was very excited about was regarding video games and how they may cause an adrenalin response in the players, but she was told she could not use this project because it involved people. She is not allowed to have any topic that uses people, animals, chemicals, testing consumer products on people or animals, or putting anything into someone's mouth (not sure how this works since you cant use people anyway). She had done a lot od research for her original idea and went to turn it in early and as told, with one day left to find something new that her idea was unacceptable. Anyway....after a great deal of brainstorming last night she determined she would like to do something regarding acid rain effect on plants, specifically lima beans.

Here is where our question comes in, this project seems very elementary. Simply making 2 to 3 concentrations of "acid rain" and testing them on plants v/s a control of distilled water. it seems like something that should be done at a much lower grade level, but she was very limited by the rules of the fair this year and was unable to locate something she liked more. Can this idea be "kicked up" a bit to make it a more advanced project in some way? What other questions could be asked?

Any help that you can offer would be greatly appreciated.

Thank you.

Pam

I agree with you that just looking at the effect of ‘acid rain’ on plant growth is not very exciting. What I would suggest to spice it up a bit is to study the effect of acid on the formation of bacterial nodules on pea plant roots. Are you familiar with legume inoculation to improve crop yield? Here’s an article that explains what it’s about: http://davesgarden.com/guides/articles/view/2429/

The pea inoculant can be bought at most garden stores and is a dry powder. Inoculants contain active Rhizobium bacteria and are specific to a certain species so alfalfa inoculant won’t work on peas. When I plant peas I soak the seeds for a few hours or overnight then toss them in a jar with some of the inoculant and plant them. The powder sticks to the seeds and after they germinate, the bacteria colonize the roots of the peas and form visible nodules. These bacteria are able to convert nitrogen gas from the air into nitrates that the peas can use—like fertilizer. This is good for farmers because it means they don’t have to apply as much expensive nitrate fertilizer to their plants.

The hypothesis I would test is: A low soil pH caused by acid rain reduces Rhizobium colonization of peas.

You will have to do some pre-experiments with just soil to determine how much ‘acid rain’ to apply. As I understand it, acid rain forms from pollutants mainly from coal-fired power plants and contains mostly sulfuric acid. To mimic the real-life acid rain conditions, then, you should water the plants with a weak solution of sulfuric acid. You said your daughter was not allowed to use chemicals, but did they mean not use chemicals on human beings or other animals, or just not use chemicals at all?

In the atmosphere, sulfur dioxide from the burning of high-sulfur coal reacts with water to form sulfuric acid that can fall as acid rain [http://en.wikipedia.org/wiki/Sulfur_dioxide] [http://en.wikipedia.org/wiki/Acid_rain]. As a substitute you can use a weak solution of sodium bisulfite. If the science project rules won’t let you do this then you can buy a soil acidification product from the garden store [https://www.rhs.org.uk/advice/profile?PID=82]. I would not use vinegar because it is chemically too different from acid rain.

Use plain topsoil for your plants that contains no fertilizer or other additives. If peas get nitrogen fertilizer then the nitrogen-fixing bacteria won’t colonize them as well. You can add some bone meal to supplement phosphorus that will help them grow better. You will also need to buy a soil test kit to measure the pH.

I know you have to submit your proposal tomorrow, so I’ll cut this short and post it so you can ask more questions if necessary.

Good luck!

Sybee

Good morning,

I am in the 8th grade and I am conducting an experiment regarding the affects of acid rain on plants. I am growing flowers (specifically petunias). I plan to have 3 groups of flowers, the control watered with distilled water, a low acid solution and a higher acid solution. Here are my questions.

1. Since I am planting these flowers from seeds, should I give regular water (distilled with no acid) to each group until they start to sprout then introduce the levels of acid rain, or should each plant be given its specified solution from the time of planting. I have found procedures on other similar experiments that stated to give the plants regular water until leaves sprouted, but I feel this may contaminate the results.

2. Would simply "misting" each plant with a water bottle filled with the solution be representative of rain? I had thought of making a terrarium for each group of plants but that turned out to be cost prohibitive. If spraying the leaves is not a good method can you please offer another suggestion. I would like to create something that would mimic rainfall (like a terrarium) but is not expensive or overly difficult to build.

3. Is there anything I can do to make this project a little more difficult? This was chose at the last minute because my other 3 ideas were rejected by my school. I do not feel this is "hard" enough for my level, but cant think of anything else to make this more interesting/involved.

Thank you for your assistance.

KM

Thank you so much for your response. Sadly I did not see this until after her proposal had to be turned in. We rain into a few snags, and had to change the type of plant being used. Apparently this is not a good time of year to find the lima beans to plant, we called many locations around town and were not able to find anything. We do have several types of flower seeds already at home and ready to go. Petunias, Moring Glories, Cosmos, and several others.

As for the "acid rain" I am not sure if she would be allowed to use actual chemicals or not. If she is able to use them, I'm not sure that I would be able to purchase a lot of extra materials for her to use at this point. Part of the reason she picked her initial project (the one that was turned down) was because we already had the necessary items, and the only costs would be materials to create her board.

She spoke to her teach who told her that she would be able to tweak her hypothesis if necessary. At this point she is very discouraged and not really wanting to participate because she feels lost and I cant say I much blame her.

That you for your suggestions, but I am afraid that I don't know how we would implement any of them.

I did post another questions earlier today, to be honest I had forgotten that we have placed a question here previously.

Thank you for your help.

Hi!

I think this sounds like a great project! And thank you for the information and they way you asked your questions, it makes it so easy to respond to you. Hear are my thoughts:

1. Acid rain would effect both the leaves of the plants and the parts of the plans in the ground. One thing you could do to make your project more complex, would be to have 5 groups of flowers. One that is always watered with distilled water, one that is watered with distilled water until leaves sprout and then is misted with low acid, one that is watered with distilled water until leaves spout and then is misted with high acid, one that is watered and misted with low acid, and one that is watered and misted with high acid. That should tell you the effect of acid rain on spouting and mature plants.

2. I think misting is a great way to deliver the acid rain to your plants. Just make sure you the same type of spray containers, on the same setting, and the same number of squirts (or whatever) to ensure consistent delivery.

3. Another thing you could try would be to use regular tap water instead of distilled water to see what effect that has on sprouting and mature plants. Also, in your "groups of flowers," you'll want to have at least 3 plants per group if you plan to do statistics. The more plants you have in each group, the better for research purposes. And finally, you could test different types of plants to see if some are more prone the effects of acid rain than others.

Good luck! Let me know if you have any other questions. I'd love to hear how your experiment went.

-Lisa

Thank you so much for your help. I had initially wanted to do a "crop" type plant, like lima beans or green beans, but I was unable to find seeds in my area this time of year.
I have 2 more questions if you don't mind offering just a little more help.

1 - Do you think that I should use multiple flowers? I have several seed varieties that I could use. Perhaps 3 different types of flowers, with 3 flowers in each group? Or would that be too much?

2- , I know that acid rain is primarily made of sulfuric acid. I was reading some procedures that use vinegar to simulate the sulfuric acid. I know that vinegar is acetic acid with a totally different chemical make up. I do not have access to pure sulfuric acid, but someone suggested using sulfuric acid drain cleaner. I did some searching and most of the labels say something like "A 93% inhibited virgin sulfuric acid drain opener with metal inhibitors" This is not pure so I'm not sure what it would do. What is something I can use, that is not expensive, (and hopefully easy to find) to simulate the acid? I also found this link showing sulfuric acid used as a pool cleaner. http://www.lesliespool.com/taylor-sulfu ... c-acid.htm Could something like this be used?

Thank you again for your help and I will be sure to let you know how the experiment goes.

Good questions.

I don't think the flowers are as important as the leaves. I guess having a plant that flowers would be useful because then you could monitor the leaves and the flowers. I would think beans would be a pretty easy thing to grow. They are easy to incubate in a window seal with damp papertowels in a ziploc bag.

Check these project ideas for types of plants you could use. These might also give you ideas on how to monitor the growth of your plants.
https://www.sciencebuddies.org/science- ... p023.shtml
https://www.sciencebuddies.org/science- ... p005.shtml
https://www.sciencebuddies.org/science- ... p036.shtml

It looks like you can buy simulated acid rain from Carolina Biological: http://www.carolina.com/pdf/msds/ACIDRAIN.pdf
If you want to try something that contains sulfuric acid, check the safety requirements of your local science fair. I think it should work, and you could always compare it to vinegar as well (since you want to increase the complexity of your project anyway).

Happy to answer more questions as you get them. Just post here, I'm monitoring this post.

Good luck!

-Lisa

Thanks for letting me know what’s happening with the science project. I’m sorry to hear that your daughter is having so many problems developing an interesting topic that is doable, but that means you have to use the greatest tool you have—the human mind!

So you don’t have money for seeds or fertilizer—just go out in the yard and dig up a square section of grass and cut it into equal pieces (How many? Depends on how many different acid rain exposures you decide to do.). Replant the grass in a clear patch of dirt with about 8 inches of space between each clump. This will be your test patch. The ‘acid rain’ can be imitated using vinegar (http://www.google.com/url?sa=t&rct=j&q= ... 0786,d.eXY)

The twist that I am thinking of for this test is to use a spray bottle to apply the vinegar solution just to the leaves rather than the roots. In areas with acid pollution, the acid is in the air regardless of whether or not it rains, so it is possible a plant’s leaves will be exposed to acid mist more often than acid rain. As a control, just spray with water. Be sure to do at least three clumps per test so you can get an average. This will make your data more statistically accurate.

You will have to decide how many spritzes to give each clump. You want to make sure the grass blades are wet with the mist but that there is not a lot of liquid running into the soil. Try to give the same amount of spray to each clump.

I would do two acid sprays—one weak acidity and one stronger. You’ll have to decide on the pH for each but I would think maybe 5 for weak and 3 for strong (see the link above). I’m not sure how often to spray—every other day?

Your hypothesis will be something like this: Acid mist from atmospheric pollutants retards growth in grass. Growth can be measured as height of the blades and maybe putting out of new grass runners. This is a project where photos are critical and you need to take a picture of the test patch from the same position and the same time of day every day. Additional close-up photos with a ruler showing growth should also be taken.

I hope this helps. When resources are limited, you have to get creative. Good science can be done with very simple tools.

Let us know if you need more help.

Good luck!

Sybee

I am hoping that you will see this, since this post is now older. I started my project using the following procedure. But apparently did something wrong, and now I am unsure what to do and an very worried.

I planted a total of 18 petunia seeds in potting soil according to package directions. Actually, it was a little more than 18 exact seeds. Each cup had 3 or 4 seeds to make sure something would sprout.

(there are 3 plants per group)
Group 1 - Control. These seeds and plants will be sprayed with only water during the experiment.
Group 2 - These seeds will be sprayed with water until sprouts appear, at which time they will begin to be sprayed with lemon juice/water solution with a pH 5.
Group 3 - These seeds will be sprayed with water until sprouts appear, at which time they will begin to be sprayed with lemon juice/water solution with a pH 3.
Group 4 - These seeds and plants will be sprayed with only a lemon juice/water solution of pH5 during the experiment.
Group 5 - These seeds and plants will be sprayed with only a lemon juice/water solution of pH3 during the experiment.

I sprayed each plant with 2 sprays from a 28oz. spray bottle. (I did measure the amount from each spray but don't have that information in front of me right now) every third day (Water Mon, Thursday, Sunday etc.). After about a week I started to notice growth in several of the cups, but was surprised to see that the control group was the last to sprout. I noted this in my journal and took measurements of each plant. I continued to repeat this. I noticed the soil seemed dry, but did not think it was too dry for my seeds. I checked my plants yesterday and noticed that the plants are gone. Not just dead but I can not see a trace of them in any of the cups. The sprouts were small, so it is possible if they died and withered I would not be able to easily see them. I don't know what caused them to die. It could be lack of water, temperature in my home (we did have a cold snap in FL last week) or perhaps my cat got into the cups. I have no evidence for this like over turned cups, but she has been known to eat house plants before.

My project is due in 2 1/2 weeks. I do not have time to redo the experiment with new seeds and I don't know what to do. At this point I have little data to show, and no plants. I know that advancing to the regionals for my area is out of the question this year with results like this, but at this point I am more concerned about my grade. I have nothing to show my teacher, no data to present.

Can you please offer a suggestion for what I can do? Any ideas or suggestions would be wonderful.

Thank you.

I am hoping that you will see this, since this post is now older. My daughter started her project using the following procedure. But apparently did something wrong. And we don't know what to do from here.

She planted a total of 18 petunia seeds in potting soil according to package directions. Actually, it was a little more than 18 exact seeds. Each cup had 3 or 4 seeds to make sure something would sprout.

(there are 3 plants per group)
Group 1 - Control. These seeds and plants will be sprayed with only water during the experiment.
Group 2 - These seeds will be sprayed with water until sprouts appear, at which time they will begin to be sprayed with lemon juice/water solution with a pH 5.
Group 3 - These seeds will be sprayed with water until sprouts appear, at which time they will begin to be sprayed with lemon juice/water solution with a pH 3.
Group 4 - These seeds and plants will be sprayed with only a lemon juice/water solution of pH5 during the experiment.
Group 5 - These seeds and plants will be sprayed with only a lemon juice/water solution of pH3 during the experiment.

She sprayed each plant with 2 sprays from a 28oz. spray bottle. (we did measure the amount from each spray but don't have that information in front of me right now) every third day (Water Mon, Thursday, Sunday etc.). After about a week she started to notice growth in several of the cups, but was surprised to see that the control group was the last to sprout. She noted this in her journal and took measurements of each plant. She noticed the soil seemed dry, but I told her I thought it was ok and to continue watering as she planned. We checked the plants yesterday and noticed that the plants are gone. Not just dead but I can not see a trace of them in any of the cups. The sprouts were small, so it is possible if they died and withered I would not be able to easily see them. I don't know what caused them to die. It could be lack of water, temperature in my home (we did have a cold snap in FL last week) or perhaps my cat got into the cups. I have no evidence for this like over turned cups, but she has been known to eat house plants before.

The project is due in 2 1/2 weeks. She does not have time to redo the experiment with new seeds and I don't know what to do. She is very stressed out and was crying last night. She said she knows that advancing to the regionals is out of the question this year with results like this, but is more concerned about her grade. She has little data and nothing to really show for her work.

Because we don't know what caused the plants to die, there is really nothing that I know to tell her. Can you offer any suggestions?

Thank you.

Since you do have a little time, why don't you simply buy some lettuce or cabbage plants from a store and try spritzing them with your 'acid rain'? Instead, you could simply dig up some plants from outside, but it would be a little harder to get ones that are all about the same size and maturity.

If you buy plants, put each one into a plastic cup with the same weight of soil. You can weigh the pot, dirt and plants after you have planted them to get a starting weight. I would water the plants well about once a week but spritz them every day to imitate acid pollution. Weigh them at one week and two weeks and hopefully that will be long enough to see a difference if there is one. Be sure to take good photos of each plant several times so you can document if there is any visible change.

Keep the plants warm, inside in front of a sunny south window and away from curious felines!

I hope this helps.

Good luck!

Sybee

PBeck,

I'm sorry to hear about your plants. In terms of your grade, my suggestion would be to start over with a different type of seed and keep closer tabs on your plants. Perhaps put them someplace where the cat can't get them. Also, when seeds are germinating, they usually like a lot of water. It could be that 2 sprays isn't enough to get them to germinate.

I found this on http://www.burpee.com/flowers/petunias/ ... 10254.html.

PETUNIA SEEDS OR PLANTS?

There are many, many kinds of petunias available as transplants in the spring either mail order or at local garden centers. You can also start petunias yourself if a certain type or color is not available as a transplant.

Be advised that growing seedlings of any plant is something of an art and it takes some extra knowledge and equipment to produce sturdy, healthy plants. Petunia seeds are notoriously slow to germinate, so start them ahead indoors in order to have seedlings ready when warm planting weather arrives. Petunias are also very tiny, so mix the seed with some dry sand so they sprinkle evenly on the growing medium.

Six to ten weeks before the date of the last expected frost in your area fill 2-inch deep flat boxes or peat pots with moist seed starter mix or soilless potting mix. Then sow the petunia seeds, pressing down lightly on them to be sure they are in contact with the growing medium.

Do not cover petunia seeds with soil, because they need light to germinate. Water from below so the seeds are not disturbed. Petunias will germinate in 5 to 15 days at normal indoor house temperatures, sooner if set on a heat mat. For optimum growth, place new sprouts under fluorescent lights for 12 hours daily to simulate late spring light conditions.

So, looking for fast germination, you could use the papertowel method shown here: https://www.youtube.com/watch?v=7D16VBtWAXw

Here's a post that talks about the quickest germinating seeds: http://homeguides.sfgate.com/plants-gro ... 53378.html

I've germinated lima beans successfully using the papertowel method. You might wish to try those: http://www.doityourself.com/stry/3-step ... -indoors#b

The great thing about using the papertowel method is that you could set the papertowels with your different treatment groups, and the ziplog bags will keep them cat proof. Then you'll at least have germination data for your experiment. If you tried a variety of seed types, then you might get enough data to get yourself to regionals using the effects of acid rain on germination.

Please write back and let me know how it goes. I'm interested! And yes, I'm keeping track of this post. I'll get an email every time you add to it. I was just out of town last week so didn't get to reply as quickly.

Good luck!
-Lisa

And I meant to say "wet the papertowels" with your different treatment groups. Then once you transplant them, you could spray the leaves (if you get that far).

Hi,
I don't know if you saw my post to your other thread about this project so i am pasting it here in case my information might be useful to you:



Re: Questions regarding project difficulty. How to beef it up

Postby SciB » Thu Nov 27, 2014 9:37 pm

Since you do have a little time, why don't you simply buy some lettuce or cabbage plants from a store and try spritzing them with your 'acid rain'? Instead, you could simply dig up some plants from outside, but it would be a little harder to get ones that are all about the same size and maturity.

If you buy plants, put each one into a plastic cup with the same weight of soil. You can weigh the pot, dirt and plants after you have planted them to get a starting weight. I would water the plants well about once a week but spritz them every day to imitate acid pollution. Weigh them at one week and two weeks and hopefully that will be long enough to see a difference if there is one. Be sure to take good photos of each plant several times so you can document if there is any visible change.

Keep the plants warm, inside in front of a sunny south window and away from curious felines!

I hope this helps.

Good luck!

Sybee

PBeck, we noticed there were two separate threads open for the same topic. Please keep all questions to one thread so that our experts can best help you based on what has already been discussed. We have merged the two threads, and you have received excellent advice from our experts so far.

Good luck, and thank you for using Science Buddies!