Introduction: (Initial Observation)
Plants absorb water and nutrients from the soil and light from the sun to grow. Nutrients for plants are also called fertilizers. All nutrients will be carried in to the plant roots and stem and leaves by water. Water can also carry harmful material in to the plant. Good nutrients can help plants grow faster, however harmful material can have a reverse effect and slow down the plant growth. Knowing what material can help plant growth and what material are harmful for plants can help us to protect our plants and produce healthier plants.
Many studies have been done to see how different material, specially material that are food for people may affect plant growth.
In this project we will study the effect of vinegar on plant growth.
Find out about plant nutrients and plant growth. Read books, magazines or ask professionals who might know in order to learn about the effect of acids and salts on plant growth. Keep track of where you got your information from.
Following are some useful links:
United States department of agriculture has a research laboratory specialized and focused on saltwater related studies. To visit their website click on http://www.ussl.ars.usda.gov/
What is the effect of Vinegar on a plants growth? We all know that plants get watered by fresh water, however, would Vinegar do the same job? Will the plants grow better or die because of the Vinegar?
When you think you know what variables may be involved, think about ways to change one at a time. If you change more than one at a time, you will not know what variable is causing your observation.
In this project our variable is watering liquid. It can be either water or vinegar. Although other variables such as temperature and light can affect the plant growth, we will keep those variables constant (unchanged). In other words all of our test plants will grow at the same temperature and the same light. In this way we know that any change in plant growth may not be caused by variation in light or heat.
Since vinegar is an acid, it can damage the plant or slow down the plant growth.
The instructions below outline a protocol for conducting plant growth experiments in the laboratory. You may want to make adaptations for use in home, a greenhouse or outdoors.
- pots or planting trays
- potting soil (compost + soil)
- light source (sunlight or artificial lighting)
1. Plant your seeds, water them, and place them in a well-lit location. Many type of seeds will work, but radish or lettuce are often chosen because they grow quickly. We have used soybeans in the following example.
2. Keep all the pots in the same setting to minimize any variation in temperature, lighting, pests, and other environmental factors. Even when the environmental conditions are kept as constant as possible, it is a good idea to randomize the grouping of plants rather than placing all the plants that are receiving the same treatment together in one group. This helps to further minimize the effect of any environmental differences.
3. Record on a daily basis the number of seeds that have germinated, plant growth, and observations about plant health such as color, vigor, or damage due to pests and diseases. You can decide what measurements to use as indicators of plant growth; possibilities include plant height, number and size of leaves.
- Get four pots and 12 soaked soybean seeds.
- Fill each pot about 2/3 full with potting soil.
- In each pot , plant 3 soybean seed covering them loosely with about 1 cm. of soil (approximately the width of the seed).
- Label two pots with control.
- Label two pots with vinegar
- Place all four pots in a tray and water with tap water until plants reach a height of 18 to 20 cm. (This will take a week to 10 days.) Make and record observations of height and any other important observation.
- When all plants have reached a height of 18 to 20 cm. , continue with the final stage of your experiment.
- Water two pots as usual with tap water. Water two other pots with vinegar instead of tap water. continue to make observations for another week.
- For a very low acidity rain, you may mix one-cup vinegar with 9 cups water.
- For a very high acidity rain you may use pure vinegar with no added water.
Materials and Equipment:
- Soybean seeds
- Small pots
- Distilled water or tap water
- Potting soil
- Metric rulers
- Trays for plants
- Watering cans
Results of Experiment (Observation):
Record the result of your observation in a table like this:
|Height before||Height after||# of Live to Dead Leaves|
|Control 1||7 in.||8 in.||25/0|
|Control 2||6 in.||7 in.||23/0|
|Control 3||7 in.||6 in.||24/0|
|Control 4||6 in.||6 in.||23/0|
This table will not show the initial plant growth period. It will show the conditions of the plant before and after using vinegar instead of water (in 2 out of 4 pots). The last column shows total number of leaves and the number of dead leaves.
Numbers in the table are not real numbers and are written here just as an example.
No calculation is required for this project.
Summary of Results:
Summarize what happened. This can be in the form of a table of processed numerical data, or graphs. It could also be a written statement of what occurred during experiments.
It is from calculations using recorded data that tables and graphs are made. Studying tables and graphs, we can see trends that tell us how different variables cause our observations. Based on these trends, we can draw conclusions about the system under study. These conclusions help us confirm or deny our original hypothesis. Often, mathematical equations can be made from graphs. These equations allow us to predict how a change will affect the system without the need to do additional experiments. Advanced levels of experimental science rely heavily on graphical and mathematical analysis of data. At this level, science becomes even more interesting and powerful.
Using the trends in your experimental data and your experimental observations, try to answer your original questions. Is your hypothesis correct? Now is the time to pull together what happened, and assess the experiments you did. This is a sample conclusion:
Vinegar affects the growth of the plant. My hypothesis was correct and two plants watered with vinegar had lower growth and got damaged. The reason that such damage was not fast is that vinegar contains about 95% water. I believe a similar test with a stronger acid can damage and destroy the plant in a much shorter time.
Related Questions & Answers:
What you have learned may allow you to answer other questions. Many questions are related. Several new questions may have occurred to you while doing experiments. You may now be able to understand or verify things that you discovered when gathering information for the project. Questions lead to more questions, which lead to additional hypothesis that need to be tested.
If you did not observe anything different than what happened with your control, the variable you changed may not affect the system you are investigating. If you did not observe a consistent, reproducible trend in your series of experimental runs there may be experimental errors affecting your results. The first thing to check is how you are making your measurements. Is the measurement method questionable or unreliable? Maybe you are reading a scale incorrectly, or maybe the measuring instrument is working erratically.
If you determine that experimental errors are influencing your results, carefully rethink the design of your experiments. Review each step of the procedure to find sources of potential errors. If possible, have a scientist review the procedure with you. Sometimes the designer of an experiment can miss the obvious.
Write a list of your references at this section. You will need to visit a local or school library and see some books about about plants, irrigation, growth and reproduction. If you see any related material in these books, add them to your report or use them in your project.
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