Soil is just rock that has been weathered. Weathering is when wind, water, or other natural agent wears away at rock. This take millions of years to happen. As the wind or water etches away at the rock, the pieces of soil or rock that come off get carried to someplace new. Soil is not just these rocks and minerals, but is also has organic or living things in it. The organic matter is called humus (pronounced hue-muss). It has tiny fungi and bacteria and lots of nutrients. These nutrients, like nitrogen or phosphorus, get deposited into the soil because of the decomposition or breaking down of dead plants and animal waste. This is what soil is!