1. by Me Period ? Science Fair 2010
Caustic Compost
by Me
Period ?
Science Fair 2010
The first slide should contain your project title and your name. Notice that the project title is not the same as your question.

2. Introduction
My family just moved into a new house, and the soil around the house is very bad. It has lots of clay and rocks, so my dad is adding grass clippings and leaves to the soil to help it grow grass in the future.
I’ve also noticed that nothing grows
under my grandma’s walnut trees
and her pine trees.
The Introduction slide should explain why this topic is important to YOU.
Is this an observation that you made?
Does this involve an activity that you like to do?
Is this something that you have heard your parents talk about?
A good introduction logically leads to the question.
Pictures are a great way to draw your audience in to the presentation.
MAKE THIS LIKE A STORY!

3. Background Research
Internet research showed that plants need nutrients in the soil to grow, as well as water and carbon dioxide. Plants also need a neutral pH in the soil to grow best.
pH is a measurement of how
much acid is in something
pH of the soil can be changed
by chemicals or by plants.
(See citations section for details)
Add the SCIENTIFIC portions of your literature research next.
Make sure you KNOW the science behind what you are about to do.
This part is vital to form a good hypothesis.

4. Question What are the effects of leaf type on compost pH?
This could also be written as…
Does the type of leaves added to a compost pile change the pH of the compost?
A great question contains both the independent variable and the dependent variable. If you can write it in the form, “What are the effects of ___ on ___? Do so. (The first blank is the independent variable, the second blank is the dependent variable.)
The question should be detailed enough that the reader can guess what the rest of the project will involve.
The question should flow naturally from the introduction.
DO NOT ask questions that begin with “Can I…”
DO NOT ask questions that begin with “How does a ____ work?”
These are not testable questions.

5. Hypothesis
If walnut leaves are added to potting soil, then the pH of the mixture will be lower than plain potting soil because walnut trees seem to prevent growth of other plants.
Remember to write your hypothesis in If…then…because format.
This makes for a lengthy sentence or two, but a well written hypothesis lets the audience know exactly what is going to happen and ties the background information in to the question.
Do not use first person pronouns (I, we, us, me) The story part of your presentation is over, now, this should be scientific.

6. Variables and Controls
Independent Variable : type of compost
Dependent Variable: pH measurement
Constants: amount of soil, amount of compost, amount of water, type of cup, length of time to decompose, stored at same temperature, measured in the same way
Control: cup with soil only and no compost
This slide proves that you know your stuff. You don’t have to read off every word, but if a judge asks, you should know WHY you have a control group, and what these big vocabulary words mean in general.

7. Human Subjects
Use this slid if you need it.

8. Materials List 2 liters distilled water
1 liter each of walnut leaves, apple leaves, aspen leaves, maple leaves, poplar leaves, fir needles, and grass clippings
8 gallon-size Ziploc bags
24 clear plastic cups
24 plastic spoons
20 liter bag of potting soil
pH meter
scissors
Make sure to list sizes, quantities, amounts, and types of materials you will be using.
Start out with a basic list, and as you do the experiment, add in anything that you use which was not on the list.
Be sure to use scientific names of instruments.

9. Procedure
Gather 1 liter (approx) of each leaf type. This includes aspen, poplar, maple, walnut, apple, fir needles, and grass clippings.
Place each type of leaves in a separate gallon-size Ziploc bag.
Let the leaves decompose inside the sealed bags for 4 weeks
In your verbal presentation, you will summarize the procedure with a few sentences.
The PowerPoint, however, should have VERY DETAILED instructions which tell exactly how you conducted your experiment. The procedure should list quantities of materials, instruments to use, math formulas used, number of repeated trials, and drawings of experiment set-up if necessary. (Draw on paper and scan to create a digital image.)
If you can, take photos of you DOING the experiment to include in your presentation. Looking at a 29-step procedure in just text is very boring!

10. Procedure Continued
Prepare the cups by mixing 150 ml of potting soil with 100 ml of distilled water in each cup. Mix with a clean plastic spoon.
Use scissors to cut up each type of leaves into pieces no larger than 1 cm. Mix 100 ml of each type of leaves into three soil cups. Mix with a clean plastic spoon each time.
Put no leaves into the three control cups.

11. Procedure Continued
Measure the pH of the soil/compost mixture in each cup, rinsing off the meter with distilled water in between each test.
Record the results and keep the cups for Phase 2 of testing.

12. Ph OF VARIOUS TYPES OF LEAVES MIXED WITH POTTING SOIL
Data
Ph OF VARIOUS TYPES OF LEAVES MIXED WITH POTTING SOIL
pH measurement
Use Excel or another spreadsheet program to create a graph. This takes some practice, so don’t wait until the last minute.
When you have the graph looking the way you want, insert it into your PowerPoint.
Make sure each axis is labeled and the graph has a title which explains what the experiment was.
This graph is missing a legend that shows that orange is trial one, brown is trial 2, and white is trial 3.
LEAF TYPE

13. Results
The data shows that the pH of the walnut leaves and soil mixture was the lowest, which means that walnut leaves have the most acid.
It was surprising to see that almost all of the soil samples had very close to the same pH.
Make a summary of your results in paragraph format too.

14. Conclusion
This experiment predicted that if walnut leaves were added to potting soil, then the pH of the mixture would be lower than plain potting soil because walnut trees seemed to prevent growth of other plants.
The data showed that walnut leaves lowered the pH the most - from neutral to just slightly acidic.
The conclusion may take more than one slide it should have 3 parts:
A. restate the hypothesis, change the verb tense
B. tell what happened – use past tense
C. state if the hypothesis was supported or not

15. Conclusion Continued
The hypothesis was partially supported because although the pH was lowest with the addition of walnut leaves, the change in pH was not significant.

16. Future Research
The acid in the walnut leaves was not enough to cause plants not to grow under the trees. There must be something else in the leaves besides acid that prevents seeds from growing. Phase 2 of the project will be to actually plant seeds in the soil cups and see which type of compost produces the most plant growth.
In real science (which this is!) an experiment usually sparks another idea, or another question, or something that happened which was not expected.
Winning projects end with ideas for future experimentation, or other avenues to explore.