What are the Effects of Acid Rain on Germination?

Researched by Cody J.


The purpose of this experiment was to determine the effect  of acid on seed germination.

I became interested in this idea because I know that  acid rain is becoming  a factor in pollution around the world.  I know this from books I've studied and news articles Iíve read.

The information gained from this experiment may warn people that acid rain can affect  seed germination.  Perhaps will show people that they need to reduce the amount of acid that is released into the atmosphere.


My hypothesis is that the percentage of seeds that germinate will decrease as the amount of acid added to the water during germination time increases.

I base my hypothesis on the following quote from Microsoft Encarta 98: "Forest lakes, ponds, and other terrestrial and aquatic environments throughout the world are being severely damaged by the effects of acid rain." And other News Articles that Iíve read.


The constants in this study were:

The manipulated variable was the concentration of the acid solution.

The responding variable was the percentage of plant seeds that germinated in fourteen days.

To measure the responding variable the number of carrot seeds that germinated were controlled to determine the percentage of the total. My definition of germination is when s green stem appears from the seed.


Quantity  Item Description
500  Carrot Seeds (packaged)
1 Roll of 29 1/2 cm X 23 1/2 cm plastic wrap
Roll of 27 1/2 cm X 23 1/2 cm paper towel
5 Containers of Acid Rain  pH solution of H20 and nitric acid
1 Graduated Cylinder
5 Glass canning jars ( 1 Quart)


1.  Take two 27 1/2 X 23 1/2 cm paper towels and tear at perforated line.
2. Tear one sheet of plastic wrap that is 29 1/2 X 23 1/2 cm.
3. Take one 1/2 gallon milk carton and cut the top of it off.
4. Make sure to wash the carton thoroughly with antibacterial soap and rinse well.
5. Measure out 500 ml. of water and pour into the clean milk carton.
6. Count 100 carrot seeds.
7. Lightly dampen the two paper towels.
8. Sure that they are both wet to the touch.
9. Place the 100 seeds in a horizontal line on the skinny sides on one paper towel.
10. Roll the paper towel up with the seeds in it.
11. Get two stripes of tape 3 centimeters long.
12. Take the other paper towel and wrap it up around the other paper towel with the seeds in it.
13. Take the sheet of plastic wrap and you wrap it around the paper towels.
14. Pull the plastic up about an inch leaving one inch of paper towel without plastic on it at the bottom.
15. Fold the excess at the top over the top of the paper towel.
16. Tape the plastic to the other side of the plastic so it doesn't unravel label as ìTrial 1î
17. Set the paper towel roll, inside the milk carton
18. Repeat steps 1-17 2 more times, except label as ìTrial 2î and ìTrial 3î
19. Repeat steps 1-18 four more times and
20. For one of the containers put 0 ml. of nitric acid in the water, put 2ml. in the second one, put 4 ml. in the third one, put 6 ml in the fourth one and 8 ml in the last one.
21. Sure to add acid into the water inside the milk container.
22. Wait 14 days with the paper towel roll in the carton at all times.
23. At the end of the 14 days take the paper towels out of the water and lay them down.
24. Carefully slide the plastic off of the paper towels.
25. Slowly unroll the paper towels.
26. Calculate the percentage and record how many seeds germinate to the point that a green root is exposed.


The original purpose of this experiment was to determine if the sulfuric and nitric mix of acid affected the seeds germination.

The results of the experiment were as I had predicted.  The trial with no acid had a higher number of seeds germinate. The trial with all acid had the lowest percentage of  seeds that  germinated. Finally, the trial with half acid and half water was in the middle of the three germination rates.


My hypothesis is that the percentage of seeds that germinate will decrease as the amount of acid added to the water during germination time increases.

I accept  my hypothesis because of the results of this experiment, I wonder what would happen  to germination when usuing a stronger acid level. I also wonder what would happen if a researcher were to record data for a lot longer than just the germination stage.  What would happen  to its growth as the plant grew and became mature in an acidic enviornment.

If I were to conduct this project again  I would have additionally used an acid mixture that was twice as strong as the acid that  I used. Then the data  collected would be better, because it would include a more extreme treatment.  That would have made the results of the experiment a little more complete and believable.



Acid rain can be very dangerous and very harmful. People need to know how dangerous acid rain is to our society us and our environment. Maybe then people will do something
about it.


Parts of a Plant

Plants are very simple organisms, they rely on food that is produced throughout their leaves.  They absorb sunlight through the leaves and it powers the creation of protein and nutrients. It is then transported through the plant by the Xylem cells and the nutrients are given to the Xylem tissue for plant use. The roots intake nutrients from the ground such as water and other  minerals found in the ground. The nutrients from the roots are then transported throughout the whole plant.  The nutrients are usually used to repair or create new cells. There are three kinds of stems: herbaceous stems are flexible and soft, woody are hard wood stems (also be called trunks), and rhizones are stems that grow underground.

Food and Energy

 Cells and tissue need a lot of nutrients to repair damage and create new cells for the plants growth.  Photosynthesis is a process in which the leaves  absorb sunlight and transform it into food for the plant.  The sun supplies the energy for the change, meaning that the plant just uses the sunlight to transform chemicals.  Carbon dioxide gas (that plants take in) is mixed with water and when combined produces sugar and oxygen.  Then the sugar and oxygen are transported throughout the plant.  Sometimes the sugar is changed into starch.  The sugar in the plant is used to make cellulose.  Plants purify the air by intaking carbon dioxide and releasing oxygen  into the atmosphere.  They then combine sugar and carbon dioxide, this chemical equation is called respiration. The chemical equation is:
C2H12O6 (sugar) + O2 (oxygen) combined  into CO2 (carbon dioxide) + H2O
Cellulose is in grass and mostly all other plants.  The grass or other plant is digested by the animal, in the form of food.


 A carrot is scientifically classified as  ìDaucus Carota.î  The carrot belongs in the Umbelliferea family.  The carrot is a biennial that only sprouts once a year.  When a carrot sprouts it forms a very small rosette by the seed which stores a surplus of food.  The root becomes very big and fleshy, which is harvested later in the year.  The carrot grows a branch that is usually 91 to 152 cm tall.


 For a plant to germinate it needs adequate water, oxygen and adequate temperature.  The seed has been dry during its dormant stage.  First water soaks into the embryo completely soaking it.  Then the seed coat swells and pretty soon the coat breaks open.  Then the oxygen is absorbed through the plant and starts to grow.  Stored food is eventually broken down by enzymes and transported throughout embryo.  The radicle is usually the first to break out of the embryo.  The radicle absorbs water by root hairs and attaches to soil.  The hypocotyl lengthens bringing the plume.  When the leaves finally sprout the process of photosynthesis starts.

Acid Rain

 Acid rain is considered any precipitation with a ph lower that 5.6.  The affect of acid rain is increasing the pH of lakes, streams and soils that are becoming very acidic. Acid rain was first recognized in the 1800ís.  Acid rain is caused when pollutants enter the air and get trapped into clouds which have  moisture in them. Acid rain is usually a combined mixture of Sulfuric and Nitric Acid. The pollutants are smoke and other gasses from engines  and  factories.

Sulfuric Acid

 Sulfuric acid is a fairly strong acid.  The concentrated acid destroys skin and flesh, and can even cause blindness if it gets into eyes. Though the acid is very harmful it has been very commercially important. Sulfuric acids chemical name is H2SO4.

Nitric Acid

 Nitric acid is a very powerful acid and is a strong oxidizing agent. The concentrated acid only contains about 71% HNO3 (Nitric acid) and the rest is water. Medieval alchemists called the acid ìaqua fortisî, meaning strong water. Calcium, sodium, potassium, and ammonium nitrates are used in fertilizers to provide a source of nitrogen for plant growth.


 Plants generate their  own  food by absorbing light and sending it throughout  its whole system. Germination is the process of a seed transforming into a full grown plant. The water  it takes in starts the process. Acid rain was know in the 1800ís but people didnít  do anything about it. Pollution is the biggest cause of acid rain. Sulfuric acid and nitric acid are both  components of acid rain and are very damaging.


ìCarrot,î Microsoft Encarta 98. 1998

DiMichele, William A, ìPlant,î World Book Encyclopedia. 1995. Vol. 15 pp. 516-517

Heimler, Daniel Locklard, Focus on Life Science Columbus, Ohio: Merill Publishing

Newman, David E., Nagel, Rob, Travers, Bridget, ìAcid Rain,î U.X.L Encyclopedia of Science. 1998. Vol. 1 pp. 9-10

ìSeed Germination,î Microsoft Encarta 98. 1993-97

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