Short explainers. Each card includes a kid-friendly version.
A vertical slice of soil shows layers called horizons. O is the surface litter, A is topsoil rich in organic matter, B holds minerals leached from above, and C is weathered parent material sitting on bedrock (R).
🐛 For kids
Soil is like a cake with layers. The top is like frosting made of leaves, then dark yummy soil where plants love to live, then lighter layers, then rocks at the bottom.
Soil texture is the mix of sand, silt, and clay. The USDA texture triangle plots those three percentages and names the result — loam, sandy loam, silty clay, and so on.
🐛 For kids
Some soil is gritty like sand at the beach, some is silky like flour, and some is sticky like clay. Most soils are a mix of all three!
Nitrogen, phosphorus, and potassium cycle between plants, microbes, and minerals. Composting, cover crops, and healthy soil biology keep these cycles running without synthetic inputs.
🐛 For kids
Plants eat tiny bits of food from the soil. Worms and bugs help turn old leaves back into food. It's a giant recycling program.
pH runs from 0 (very acidic) to 14 (very alkaline). Most plants prefer 6.0 to 7.5. Blueberries want acid (4.5–5.5), while lavender tolerates alkaline (7.0–8.5).
🐛 For kids
pH tells you if soil is sour or sweet. Most plants like it just in the middle — not too sour, not too sweet.