What on Earth is Soil?

Soil is the thin layer of material on the Earth’s surface. It is made up of many decayed plant and animal matter. I heard it takes more than 1000 years for one small amount of soil to form.

Soil makes almost everything on Earth possible Soil makes almost everything on Earth possible. Soil holds heat, water and food for plants. Soil provides shelter and food for animals. People use soil to farm and grow food. I help the soil. I eat decaying plants and break them down. I love to make tunnels in the soil to help air and water reach plants.

Did you know that soil is not all the same? Really!

That doesn’t sound good! Sandy soil is loose and has tiny pieces of rock. It cannot hold enough water or nutrients for my friends and I to grow well in. That doesn’t sound good!

It must be hard for your roots to grow in the clay. Clay is wet and sticky and has fine grains. Clay has many nutrients but plants do not grow well in it. It must be hard for your roots to grow in the clay.

What about silt? Silt has grains that are smaller than sand but larger than clay.

This loam looks like a great place for me, you and your friends to grow. You are right! Loam is a mixture of sand, clay and silt. Loam is good soil for farming. It has many nutrients and holds water.

Soil is our home and my friends and I have a big job. Our roots help break up rocks which become part of new soil. Our roots loosen the soil, allowing oxygen to penetrate. This helps animals living in the soil. Our roots hold soil together and help prevent erosion.

My friends and I have a big job too! Earthworms digest organic matter, recycle nutrients, and make the surface soil richer.