The clumping of the soil textural components of sand, silt and clay forms aggregates and the further association of those aggregates into larger units forms soil structures called peds. The soil structure affects aeration, water movement, conduction of heat, plant root growth and resistance to erosion. Water has the strongest effect on soil structure due to its solution and precipitation of minerals and its effect on plant growth.

The original definition of the solum was the topsoil (‘A’ horizons) + subsoil (‘E’ and ‘B’) horizons; where the ‘C’ horizons were defined as strata with little evidence of pedogenesis. The “effective” soil depth then was considered the solum thickness. However, roots and biological activity occurs often in the C horizon and soil depth should hence include this layer. In practice soil surveys use arbitrary depth limits (eg 200 cm) to study soils.

The moisture stored in or flowing through the soil affects soil formation, structure, stability and erosion and is of primary concern with respect to plant growth.

When a field is flooded, the air space is displaced by water. The field will drain under the force of gravity until it reaches what is calledfield capacity (FC), at which point the smallest pores are filled with water and the largest with water and air. Field capacity corresponds with a suction equivalent of 1/3 bar. Plants that use the water must produce increasingly higher suction, finally up to 15 bar. At 15 bar suction, the soil water amount is called wilting point (WP). At that suction the plant cannot sustain its water needs as water is still being lost from the plant by transpiration; the plant's turgidity is lost, and it wilts. The amount of water remaining in a soil drained to field capacity and the amount that is available are functions of mainly soil texture. The available soil moisture can be determined in the laboratory as shown in the soil moisture retention curves.

The mineral components of soil, sand, silt and clay, determine a soil's texture. Soil texture affects soil behavior, in particular its retention capacity for nutrients and water.

Soil components larger than 2.0 mm are considered as rock and gravel and can be included in textural class.For example, a sandy loam soil with 20% gravel would be called  a gravelly sandy loam. When the organic component of a soil is substantial, the soil is called organic soil rather than mineral soil.