Soil Structure

Soil Fertility Life Beneath

Damaged soil structure will reduce grass yields, limit grazing days and also cost money because of the costs of remediation. Read more about the cost of poor soil structure

Soil Block - StructureThe pore space in soil controls the balance of oxygen and water available to plant roots and soil organisms. Clay soils usually have more small pores than sandy soils that and can hold on to more water for longer. Soil structure depends on how the mineral particles are aggregated together with soil organic matter.

Bigger (transmission) pores in which water moves easily are >150 μm in diameter (just thicker than a human hair) and in topsoil these pores are usually filled with air, but plant roots can effectively extract water from pores as small as 0.2 µm (smaller than a bacterial cell).

Plant roots and some soil organisms (known as ‘ecosystem engineers’) change the structure of soil by moving through the soil, moving soil particles around and extracting water. Along with a range of physical processes, these biological interactions have a central role in soil structure development and create micro-habitats for other soil organisms; in temperate agro-ecosystems, earthworms are very dominant within this group.

Supporting the biological processes of structure formation and increasing soil organic matter content have been shown to help create resilient soil structures that can both absorb heavy rainfall and hold water in drought; however, the mechanisms supporting structural resilience are not yet well understood.

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