Mar 19, 2025 · Soil, the biologically active, porous medium that has developed in the uppermost layer of Earth’s crust. It is one of the principal substrata of life on Earth, serving as a reservoir of water and nutrients, as a medium for the filtration and breakdown of wastes, and as a participant in the cycling of elements.

Mar 19, 2025 · Soils have a unique structural characteristic that distinguishes them from mere earth materials: a vertical sequence of layers produced by the combined actions of percolating waters and living organisms.

Mar 19, 2025 · The evolution of soils and their properties is called soil formation, and pedologists have identified five fundamental soil formation processes that influence soil properties. These five “state factors” are parent material, topography , climate , organisms, and time.

Feb 21, 2025 · horizon, a distinct layer of soil, approximately parallel with the land surface, whose properties develop from the combined actions of living organisms and percolating water. Because these actions can vary in their effects with increasing depth, it is often the case that more than one horizon exists beneath the surface of any soil area, at ...

Mar 19, 2025 · Central to both systems is the notion of diagnostic horizons, well-defined soil layers whose structure and origin may be correlated to soil-forming processes and can be used to distinguish among soil units at the highest level of classification (see the table of primary diagnostic horizons).

Soil is not as solid as rock. It has many small spaces, called pores, that hold water and air. In some places on Earth, a thin layer of soil only 6 inches (15 centimeters) thick lies on top of rock. In other places, though, soil may be hundreds of feet deep.

Mar 19, 2025 · Climate influences soil formation primarily through effects of water and solar energy. Water is the solvent in which chemical reactions take place in the soil, and it is essential to the life cycles of soil organisms. Water is also the principal medium for the erosive or percolative transport of solid particles.

Mar 19, 2025 · Soil - Structure, Composition, Properties: The grain size of soil particles and the aggregate structures they form affect the ability of a soil to transport and retain water, air, and nutrients.

In soil: Parent material …and promotes the development of E horizons (the leached lower regions of the topmost soil layer). The fine texture of basaltic rocks, on the other hand, yields soils with a loam or clay-loam texture and hinders the development of E horizons.

Soil fertility is the quality of a soil that enables it to provide compounds in adequate amounts and proper balance to promote growth of plants when other factors (such as light, moisture, temperature, and soil structure) are favourable.