1. It is mostly covered by sand, soil, water, and even ice
Answers
Answer:
Soil is loose material which lies on top of the land. It has many things in it, like tiny grains of rock, minerals, water and air. Soil also has living things and dead things in it: "organic matter". Soil is important for life on Earth.
Surface-water-gley developed in glacial "till", Northern Ireland.
Loess field in Germany (loess is wind-blown dust that is mostly silt)
This is a diagram and related photograph of soil layers from bedrock to soil.
A, B, and C represent the soil profile; A is the topsoil; B is a loose soil; C is weathered rock; the bottom-most layer is the bedrock.
Because soil holds water and nutrients, it is an ideal place for plants to grow. Soil holds the roots, and lets plants stand above the ground to collect the light they need to live. Almost as important are the fungi. There are fungi which grow into plant roots, a symbiosis known as mycorrhiza. This helps trees grow. There are many other fungi that live by breaking down dead organic material: the remains of other living things. The broken down material is a main source of plant nutrients.
Many animals dig into the soil and make the soil their home. The large animals use soil to make dens for sleeping and giving birth. The small animals live most of their life in the soil. Earthworms are famous for improving soil. This is because the holes they make let air go into the soil. The holes also let water go through.
The soil also has many microorganisms living in it. Many of them eat the organic material in the soil. They use oxygen and release carbon dioxide. They also release mineral nutrients into the soil.
Soil is different in different places on Earth. This is because the climate and rocks in the Earth are different in different places on Earth. Soils are usually thicker in places where ice sheets covered the ground during the Pleistocene ice ages. This is because the ice sheets ground the rock into powder as they slowly moved over the surface.