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What is Soil Structure

So now you are up to speed on soil texture and what the individual particles in your soil are.

SOIL STRUCTURE is simply referring to the arrangement of these soil particles into larger aggregates of different sizes and shapes and the pore spaces that are left between them. It is into these spaces that root hairs will grow and extract the water and oxygen from the soil.

Sand Grains  Clay

Good soil structure for plant growth is one that has stable aggregates between 0.5 and 2mm in diameter. This results in a good network of soil pores that have good aeration and drainage that allows for rapid exchange of air and water with plant roots.

The processes of root penetration, wetting and drying cycles, freezing and thawing, and animal activity combined with inorganic and organic cementing agents produce soil structure.

In sandy soils, aggregate stability is often difficult to maintain due to low organic matter, low clay content and resistance of sand particles to cementing processes. In clay soils, aggregates may be so large that there is insufficient pore space to allow root hairs to grow between them.

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