Soil structure

Soil structure is the architecture of the soil. It is usually described by the size, shape, and stability of units (called aggregates, crumbs, blocks or peds) in which the particles (sand, silt, clay, and organic matter) of the soil are held together.

Crop growth relies on good soil aeration (for respiration), drainage, and the efficient supply of nutrients and water.

Soil drainage (how quickly water drains from the land) is determined by soil texture and soil structure. Well-structured sandy and light silty soils tend to drain more quickly than medium-textured soils, and medium soils more rapidly than heavy soils.

However, if the soil is compacted, drainage can be slow, irrespective of the soil texture.

Better structured soils:

• Are less prone to erosion and surface run-off
• Increase opportunities to access land and the duration of the cultivation window (improved timeliness)
• Reduce irrigation costs
• Reduce tillage costs (in terms of tractor hours, number of passes, and size of tractor and implements required)
• Can improve the uniformity and overall yield of commercial crops

Biological interactions in the topsoil help maintain soil structure in the rooting zone. It is important to maintain good air-filled porosity.

Poorly structured or compacted soils reduce water infiltration and can lead to surface run-off and erosion.

Soil moisture should be assessed before cultivations to avoid structural damage. 

If you would like to order a hard copy of Principles of soil management, please use our online order form or call 0247 799 0069.