☕ Kitchen scraps as plant food: the whole packet

☕ Kitchen scraps as plant food · 4th–8th grade · 21 days of testing · about $3 · 20 minutes a sitting

My days, if the fair is 25 days away

Count back from your fair day and write in each date. Fewer days than this? The jobs share days, in this order; nothing is skipped.

Dates from my teacher

• My question is due
• Testing starts
• My results table and graph are due
• My board is due

In this packet

1. 🗓️ My project plan
2. 💭 My hypothesis
3. 🧺 Change, measure, keep the same
4. 🪜 My steps
5. 📊 My results
6. 📓 My logbook
7. ✅ My conclusion
8. ✂️ Board titles to cut out
9. 🏅 The judge's questions and my certificate

If I change what is mixed into the soil, then how tall the tallest blade of grass is on day 21 will ________________, because _____________________________________________

What I think will happen, in my own words:

3 levels × 3 tries at each = 9 tries in all. If anything you keep the same changes, you won't know which change made the difference.

What I need

• 🌾 Grass seed
• 🥤 Paper cups with a hole poked in the bottom: 9, all the same
• 🪴 Potting soil
• ☕ Used coffee grounds, dried: 3 tablespoons, dried
• 🥚 Eggshells, rinsed and crushed: 3 tablespoons, crushed
• 🥣 A big bowl: 2, for mixing
• 🍽️ A baking tray or big plate: 1, to stand the cups on
• 🥛 A measuring cup
• 🥄 Measuring spoons
• 🚰 Water from the tap
• 🩹 Masking tape, to mark lines
• 🖍️ Crayons or markers
• 📏 A ruler

Be safe: 🧼 Wash your hands after · 🚫 Test food is not for eating · 🧽 A bit messy

1. Rinse some eggshells, let them dry, and crush them into tiny bits.
2. In one bowl, stir 3 cups of potting soil with 3 tablespoons of dried coffee grounds.
3. In a second bowl, stir 3 cups of potting soil with 3 tablespoons of crushed eggshell.
4. Fill three cups with plain soil, three with the coffee soil and three with the eggshell soil.
5. Label the cups plain, coffee and eggshell, and stand them on a tray.
6. Sprinkle a teaspoon of grass seed on top of each cup, and cover it with a thin layer of its own soil.
7. Water each cup with a quarter cup of tap water, and set them all on the same sunny windowsill.
8. Every other day, give each cup the same quarter cup of water.
9. On day 21, measure the tallest blade of grass in each cup in centimetres.
10. Write each height in your table, and note if the grass is pale, bright or dark green.
11. Find the mean height for each soil and draw a bar graph.
12. Wash your hands well after touching the soil, the coffee grounds and the eggshells.

Write each number in your results table the moment you measure it.

I changed: Soil   I measured: how tall the tallest blade of grass is on day 21 (cm)

MY GRAPH (a bar graph: soil along the bottom, cm up the side)

What I noticed: ______________________________________________

Write something every day you work on it, even the days you only gather things. More days? The three-page logbook prints from peabody.kids/science-fair/templates/logbook.

My hypothesis was ☐ right ☐ partly right ☐ not right.

I know because my numbers show:

What surprised me, or what might have gone wrong (7th and up):

Next time I would test:

Idea: Change a second thing: use one, two and four tablespoons of coffee grounds in each 3 cups of soil, and graph the height against the amount.

1. What made you want to ask this question? Say something like: I wanted to know: which kitchen scrap helps a plant grow most?
2. What did you think would happen, and why? Say something like: I thought changing what is mixed into the soil would change how tall the tallest blade of grass is on day 21, and I wrote down why.
3. What did you change, and what did you measure? Say something like: I changed what is mixed into the soil (Plain soil, Soil with coffee grounds, Soil with crushed eggshell) and measured how tall the tallest blade of grass is on day 21 in cm.
4. What did you keep the same, and why does that matter? Say something like: I kept the same amount of grass seed, a teaspoon in each cup and the same potting soil and cups the same, so only what is mixed into the soil was different.
5. How many times did you test it? Say something like: 3 times at each of my 3 levels, and I found the middle number.
6. What did you find out? Show me in your numbers. Say something like: Look at my table: Plain soil and Soil with crushed eggshell gave different numbers, and here's the pattern.
7. Was your hypothesis right? How do you know? Say something like: My numbers show whether I was right, partly right or not, and I can show you where.
8. Did anything go wrong, or surprise you? Say something like: One try was odd, so I did it again and wrote it in my logbook.
9. If you did it again, what would you change or test next? Say something like: I'd change a second thing: use one, two and four tablespoons of coffee grounds in each 3 cups of soil, and graph the height against the amount.