Organic Soil

This includes a range of soil classifications, depending upon the relative proportion of organic matter, degree of humification and moisture content. Soils that are wet will have low rates of decomposition and this results in a build-up of organic material, resulting in bogs or fens, both being peats. Organic soils will typically have a depth of at least 400mm and provide a mechanism to capture and store significant quantities of carbon dioxide, helping to mitigate climate change, and also storing vast quantities of water helping to reduce flood risk.

The percentage of organic matter within an organic soil will vary depending on the classification type, but typically a minimum of 20% organic matter is need for a peaty loam, increasing to at least 50% for a peat soil.

These soils are dark in colour, often acidic (but can be more neutral in soil pH) and nutrient poor, although if extracted for the making of composts and rootzones or top-dressings then they are capable of improving nutrient and moisture retention, aiding plant growth. Due to significantly declining area of peatlands within the UK the extraction of peat is environmentally questionable and usually undesirable for many situations.