ELI5: Explain Like I'm 5

Soil horizon

Imagine that the ground outside is like a big, yummy cake. When bakers make a cake, they often do it in layers. They put frosting in between the layers to make it taste even better. Well, the ground is sort of like that. The ground has layers called soil horizons, and each one is a little different.

The very top layer is called the "O Horizon." This is the layer that has leaves and other things that fall to the ground. It's kind of like a layer of cake crumbs on top of the frosting.

Next comes the "A Horizon." This layer is made up of a mix of minerals, organic material (like dead plants), and tiny living things like bugs and worms. It's kind of like the cake part of the layer cake.

The "B Horizon" is next. This layer is made up of bigger rocks and minerals that were broken down by weather and time. It's kind of like the crunchy nuts you sometimes find in cake.

Under the B horizon is the "C Horizon." This is a layer of rocks that is not really affected by the weather or other stuff above it. It's sort of like the cake plate that the whole cake sits on.

These soil horizons are important because they help plants grow. Each layer has different nutrients and minerals that plants need to survive. So, soil horizons are like the ingredients that make a cake taste great - if you don't have the right ingredients, the cake won't turn out very good.
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