Muck soil containing . . . . . . . . organic matter.

Muck is sapric soil that is naturally waterlogged or artificially drained. These soils are deep, dark coloured, and friable. Muck soil is used for growing specialty crops such as onion, carrots, celery and potatoes.
Muck soil contains about 20 - 50% organic matter. Muck farming on drained swamps is an important part of agriculture.