clab-tem4

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Broad Question
How do plants grow?

Specific Question
Can salt in a rye seeds environment effect it's growth?

Independent Variable:
Amount of salt in the water.

Dependent Variable:
Amount of growth

Variables That Need To Be Controlled:
Amount of light Amount of water Brand of paper towels Source of water (Tap) Additives to salt (no iodine)

Hypothesis
I hypothesize that the bag with the smallest amount of salt (that still has salt in it) will grow the fastest.

General Plan
My experiment will determine the effects of salinity on the growth and germination of rye. I will conduct the experiment at my house. I will be the only one involved in this experiment, and I will be doing all of the steps on my own. There will be six seeds in each bag, and there will be five bags, making there a total of thirty trials. I will record the information digitally while doing the experiment on a Google documents spreadsheet. I will document the experiment using pictures, that I will either form into a slide show, or paste onto my presentation.

Materials List

 * Kosher salt
 * 5 plastic resealable bags
 * Rye seeds
 * Well water
 * Unprinted paper towels
 * Box or container that wont let in light
 * Graduated cylinder
 * Ruler (mm)
 * Microscope or magnifying glass
 * Triple beam balance or electronic scale
 * 5 cups

Detailed Procedure

 * 1) Measure out 32ml of water 5 times, and add each to its own cup
 * 2) Measure 18g 8g, 4g, and 2g of salt.
 * 3) Stir each salt amount into a different container; label each one.
 * 4) Soak a paper towel square lightly in a salt mixture until moist, and place in a bag; Label the bag.
 * 5) Repeat step 4 with other salt solutions.
 * 6) Place six seeds in each bag with the paper towels, giving each seed its at least an inch of space from one another.
 * 7) Seal the bags and place in box. Let sit for at least 2 days.
 * 8) Remove seeds from box and measure the amount of growth on each seed. Record.

Background Research

 * Some salinity in the soil can promote absorption of nutrients; to much can weaken the plant and leave it susceptible to disease.
 * In coastal pastures, in such places as Louisiana, plants die from lack of water, since the water they’re given is full of salt
 * In places where the soil salinity is too high, plants die of water stress even if they are given a generous amount of water.
 * 20% of land in the United States is suffering from high soil salinity.
 * Sodium chloride (NaCl) and sodium sulfate (NaSO4) are the two most harmful salts to plants.
 * Salt robs plants of essential nutrients.
 * Rye is generally drought resistant, and its stems and leaves have a high calcium content to help prevent wilting, making rye less susceptible to salt.
 * Too much salt in the soil mimics drought conditions for the plants.

Data Table
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Graphs
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Photos




Conclusion
The purpose of the is experiment was to see how soil salinity would effect the growth of rye seeds. The growth was determined the length of the rye shoot after 5 days. The results showed that even a small amount of salt can slow down or completely stop a rye seed from germinating and growing. The Salt-less bag showed about an average 50mm of growth. All other bags (M2mg, 4mg, 8mg and 12mg) showed no growth what so ever. Each salt amount had six seeds, and each had it own space. They all were given the same amount of water (32 ml) time and light exposure.

Discussion
My hypothesis was that the bag with 2mg of salt would grow the most. My results do not support my hypothesis. There is a relationship between the dependent and independent variables. A pattern my data show is that any amount of salt in the water stunts the growth of the seeding completely. for example, the saltless bag was the only one that showed growth, while all other bags didnt grow at all. I think the test i did went smoothly with minor problems. It took me a few tries to get started, and the seeds took longer than expected to grow. If i could improve my experiment, i would give the seeds a longer time to grow to see if the bags with salt would grow at all or use have lower salinity levels for the seeds to grow in. An interesting future study might involve using different additives besides salt, like sugar or alum, to see if they would aid or stunt growth like salt.