Science 4º CEIP Alto Ebro: SOIL

Soil is the top layer or the Earth´s surface. It is made up of rocks, sand, minerals, air, water and humus.

Humus is the remains of dead plants and animals.

Soil is very important for plants, animals and humus.

Soil is made up of different layers:

TOPSOIL: This layer contains sand, clay, water, air and humus. Small animals, such as moles, snails, worms and ants live here.

SUBSOIL: The rock fragments are bigger. There is less water, less air and very little humus. There are very few living things.

BEDROCK: This layer is made up of large rocks. There are no living things, and very little water or air.

There are different TYPES OF SOIL because they contain different mixtures of rocks, minerals and humus.

Fertile soil contains a lot of water, air and humus. Plants grow well here.

Poor soil contains very little water, air or humus. Only a few plants, like olive trees and cereals grow well here.

Arid soil. This is very poor soil, for example, soil in the desert. It is made up of rocks and sand and no humus. Only plants like cactuses can grow here.

Classify the materials of the soil

Science 4º CEIP Alto Ebro