Soil!

Soil is the loose upper layer of the earth’s crust where plants grow.

Soil is made from organic material (decayed plants, animals, broken down rocks and minerals).

Soil makes the outer most layer of our planet. There are 3 main types of soil, sand silt and clay. Clay has the smallest partials and does not have many nutrients, clay feels hard as stone when dry and sticky when wet. Silt is a medium sized partials and has lots of nutrients, silt feels slippery when wet and powdery when dry. Sand is the largest partial found in soil and has medium nutrients sand feels rough and gritty.

Soil is formed over a long period of time in fact soil can take over 1000 years for just 3cm of soil to form! Soil includes rotting plants, fungi, animals and bacteria. How things grow depends on the land and the soil also it depends about climate and weather. There are 5 layers in soil - humus, topsoil, subsoil, and parent material and bed rock. Here is a diagram of soil.

                

Humus is a thick layer of organic matter. Topsoil is a thin layer of organic matter and minerals. Subsoil is made from clay, iron and organic matter.  Parent material is made from mainly large rock.  Bedrock is made from large solid masses of rock.

Soil is very important because we couldn’t grow food, and we would not be able to breathe without soil because plants give us oxygen that is why soil is important.

Written by Eve Bretherton