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Brown Earths

Brown Earth Soil Profile
Doune Series: Brown forest soil developed on acidic, fluvioglacial deposits

Brown soils, often referred to as brown forest soils or brown earths, are well drained with brownish subsoils where iron oxides created through weathering processes are bonded to silicate clays.

Other properties such as texture and level of fertility depend on the nature of the parent material and the degree of alteration it has undergone. In Scotland, their occurrence is restricted to the warmer, drier climate characteristic of eastern areas but they also occur in sheltered highland glens at lower elevations and on areas of base-rich parent materials. Under natural conditions the soils would form under broadleaf forest which promotes rapid decomposition of plant residue and consequent recycling of plant nutrients.

Profile Characteristics

Ah Surface horizon, usually relatively thin with organic material (mull humus) incorporated throughout mineral matrix.
Bw Brightly coloured mineral subsoil, with good structural development, generally merges into:
C Relatively unaltered parent material, usually brightly coloured or colour inherited directly from parent rock.

Distribution of Brown Earths

Two factors have influenced the development of these soils:

  • Sufficient depth of soil parent material, which is neither extremely siliceous nor extremely calcareous, and which is permeable to permit free aeration.
  • A bioclimate regime, which promotes rapid decomposition of plant residues and recycling of plant nutrients. Where this happens the plant residues are broken down by fungi/ bacteria
    to be incorporated into the soil by earthworms to create MULL humus. If the breakdown is slower, moder humus is formed. Subsequently hydrous iron oxides inherited from the parent material or formed by weathering remain attached to any silicate clays.

UTILISATION

Given the deep nature of these soils, their free drainage and often high levels  of natural fertility, brown soils are often cultivated.

These soils at lower levels in the Straths and glens of the Highlands are often cultivated for fodder crops or support the better quality grassland.

Learning & Resources


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The James Hutton Research Institute is the result of the merger in April 2011 of MLURI and SCRI. This merger formed a new powerhouse for research into food, land use, and climate change.