🌱 Grass roots and washed-away soil: the whole packet

🌱 Grass roots and washed-away soil · 4th–8th grade · 14 days of testing · about $3 · 40 minutes a sitting

My days, if the fair is 18 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 covers the soil, then how deep the washed-away mud is in the cup after 15 minutes 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

• 🍽️ Paper plates: 9 sturdy ones, all the same
• 🟫 Soil dug from the garden or yard: 9 cups
• 🌾 Grass seed
• 🥄 Measuring spoons
• 🚰 Water from the tap
• 🥄 A spoon
• 🌿 A leafy bush or tree outside, or a big potted plant: for a handful of dry fallen leaves
• 📦 Flat cardboard: a flat piece, about 40 cm
• 📚 Some books: 2
• 🩹 Masking tape, to mark lines
• 🥣 A big bowl: a big one
• 🥛 A measuring cup
• 🥛 Clear plastic cups, all the same size: 9 tall ones
• 📏 A ruler

Be safe: 🌳 Outside · 🧼 Wash your hands after · 🧽 A bit messy

1. Fill nine paper plates with garden soil right up to the rim, and pat it flat with a spoon.
2. Sprinkle a teaspoon of grass seed over three of the plates and press it in gently.
3. Stand all nine plates in one bright, sheltered spot, on trays or plastic bags to catch the drips.
4. Every day for fourteen days, give each plate two tablespoons of water.
5. On day fourteen, lay one flat layer of dry leaves over three of the bare plates.
6. Work outside or at the sink: prop one end of the cardboard on two books, its other end at a table's edge.
7. Tape a plate to the low end so that its edge hangs over a big bowl.
8. Pour one cup of water slowly onto the top of the soil while you count to ten.
9. Pour the muddy water into a tall clear cup, and label it grass, leaves or bare.
10. Test all nine plates the same way, mixing up the order of the three kinds.
11. Leave the cups still for 15 minutes, then stand a ruler against each and measure the mud in mm.
12. Muddy water is never for drinking: pour it onto the garden when you've finished.
13. Find the mean mud depth for each cover and draw a bar graph.
14. Wash your hands after touching the soil.

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

I changed: Soil cover   I measured: how deep the washed-away mud is in the cup after 15 minutes (mm)

MY GRAPH (a bar graph: soil cover along the bottom, mm 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: let the grass grow for 7, 14 and 21 days before you test it, and graph the mud depth against the days.

1. What made you want to ask this question? Say something like: I wanted to know: do grass roots stop soil washing away?
2. What did you think would happen, and why? Say something like: I thought changing what covers the soil would change how deep the washed-away mud is in the cup after 15 minutes, and I wrote down why.
3. What did you change, and what did you measure? Say something like: I changed what covers the soil (Bare soil, Grass grown for two weeks, A cover of dry leaves) and measured how deep the washed-away mud is in the cup after 15 minutes in mm.
4. What did you keep the same, and why does that matter? Say something like: I kept the same garden soil, patted down the same way and the same slope for every plate the same, so only what covers 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: Bare soil and A cover of dry leaves 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: let the grass grow for 7, 14 and 21 days before you test it, and graph the mud depth against the days.