Soil structure is a measure of the arrangement of these soil particles and the spaces between them. Soil structure is somewhat dependent on soil texture.
There are two main types of structureless or non-structured soil:
- Single grain – like sands, and
- Massive – like compacted clays.
There are four main types of soil structure:
- Crumb structure – which has small rounded aggregates of soil particles loosely adjoining other aggregates. This soil is therefore porous and permeable, yet retains moisture. It is the most ideal soil structure.
- Prismatic structure – which forms aggregates in columns with flat tops and separated by deep cracks. Aggregates usually form larger units called clods. Permeability is variable – better around the deep cracks and poorer inside columns.
- Blocky structure – aggregates are blocky and soil is moderately permeable.
- Platey structure – flat horizontal laminated aggregates like alluvial floodplain soil. Drainage and permeability are poor.
