My hypothesis is that the salt water will help the soil and leaves but not the height. The regular water will advance in height more than anything else but it will also be slow.

The salt water causes the plant to lose water as the salt in the soil will suck water out of the roots and can also burn the roots due to it being made of sodium and chloride which are toxic to plants. A normal plant pulls water up through its roots since the concentration in the roots is higher that the concentration in the soil the water goes into the roots, when we put salt in the soil that reverses and the water leaves the roots.

Independent - Salt water - One plant will be watered with salt water and one with regular water. Dependent - Plant Growth and Height - Measured using ruler from the top of pot. Controlled - Amount of water, Temperature, Light, Type of Plant - equal amount of water for both plants and they will be placed in the same place.

1. Place plants in a set place for control
2. Water both plants with 1/4 cup of water
3. Control plant should have regular water and test plant should have 1 tbsp of salt added to water
4. Measure the height of the plant from top of the pot
5. Record all values
6. Repeat steps 2 - 5 every other day

Data 

As seen above we can see the growth between the 2 plants differ, the plant with salt water (Plant A) saw a decrease in size as the time went on. The biggest thing seen was Plant A dying towards the end. This shows that not only had the salt water stopped and reduced growth but had killed the plant as well. There were leaves falling off and the plant had lost all of its color.

Before: Leaves falling off:

After:

The graph shows that the salt water which was the only variable between the 2 plants had killed the plant. The graph can be used to see directly how the height which was mainly based on the main stem had decreased. This shows how the stem had died and ended up falling over by the end. The data shows that plant A was actually growing from day 1 - 6 and started dying after which may have been caused by the salt in the soil becoming enough to start truly effecting it. On average the lost 0.75 cm per 2 days, while decreasing 1.54cm per 2 days in the last 7 days.

My hypothesis was incorrect because plant A decreased in height and died while my hypothesis predicted that it would not effect the growth. This was caused by the roots losing water to the highly salt filled soil in order to balance concentrations. This took water out of the plant and caused it to die mainly by dehydration.

This experiments results could be applied in many situation. We can look at the data to prove the dehydration effect of saltwater, the experiment could be altered to see how much salt is in an environment by comparing concentration of salt water before and after. We could also look at plants in nature and compare them to plants in a controlled environment and see how they deal with the effect of salt or other things that effect that area.

Measurement was made using a standard ruler which introduces the chance of measurements being slightly off. The plants were as close to the same as possible with simpler size, branches, and leaves however factors that were there before I got the plants which how much water they got or the sunlight could have changes things for either plant. More plants could reduce this source of error by creating more data.

https://www.youtube.com/watch?v=5eA56DZtN0g&t=12s

https://watereuse.org/salinitymanagement/le/le_2.html#:\~:text=Due%20to%20osmosis%2C%20water%20naturally,Next%20page%20%C2%BB

https://www.jennychem.com/blogs/news/does-salt-kill-weeds

N/A

https://www.youtube.com/watch?v=5eA56DZtN0g&t=12s

https://watereuse.org/salinitymanagement/le/le_2.html#:\~:text=Due%20to%20osmosis%2C%20water%20naturally,Next%20page%20%C2%BB

https://www.jennychem.com/blogs/news/does-salt-kill-weeds