Soils composed mainly of organic materials.

  • at least 20-30% organic matter by weight
  • more than 40cm (16 inches) thick


Most histosols form in wetland settings that restrict decomposition.

Often referred to as peats and mucks.

Often mined for fuel and horticultural products.







Lower Coastal Plain, North Carolina

Form in broad, flat areas.







Histosol - Southern Michigan

Highly decomposed muck
overlying undecomposed peat.










Histosol - Idaho


Soils formed in these flat, low-lying areas contain very little mineral material and are composed almost entirely of organic matter.


When drained and cultivated these soils produce high yields.

Once exposed to oxidizing conditions, the begin to decompose rapidly.

Subsidence of the land surface will follow.



Volume Change in Drained Organic Material




Everglades, Florida

Post was installed in 1924, with top of post at land surface.

This photo taken about 1975.

Soil subsided four (4) feet.




Scotland - Histosols used as fuels.

Histosols have an energy value of 8300 BTUs compared to 6000 for wood and 9500 for lignite coal.

Organic matter of this soil ranges from 89% to 96%.