Soil doesn't cover all of the Earth. Soil is a mixture of organic matter, minerals, and gases that support plant growth. It covers only the Earth's land surfaces and is typically found in the upper layer of the Earth's crust.

The total land area of the Earth is approximately 148 million square kilometers, which is about 29 percent of the total surface area of the planet. Soil covers a significant portion of the land area but is not present everywhere. Some areas, such as deserts, mountains, and polar regions, have little to no soil.

The thickness of soil can also vary greatly, ranging from a few millimeters to several meters. The deepest soils are typically found in river basins and other areas where sediment has been deposited over a long period of time.