Gleyed soil and stagnosol (pseudogley)

Gleying means that rainwater is temporarily held in the soil above a slowly permeable layer. The soil alternates between waterlogged and dry, and its profile shows typical marbling - a mosaic of grey and rusty mottles caused by the alternating reduction and oxidation of iron. Where this process is the defining feature, the soil is a separate soil type, pseudoglej (a Stagnosol in the international WRB classification). Unlike gleysols, which are shaped by a high groundwater table, stagnosols are affected mainly by rainwater.

How to recognise it in the BPEJ code

Decree No. 227/2018 Coll. expresses gleying in the description of the main soil unit (second and third digits of the BPEJ code):

• 42 and 45: gleyed brown earths, prone to temporary waterlogging
• 43 and 46: gleyed luvic brown earths and luvisols
• 44 and 47: stagnosols on loess and slope loams
• 50 and 52 to 54: stagnosols and gleyed cambisols on hard rocks and on sediments, often clayey or marly

What it means for a buyer

Agriculturally these are mostly lower-yield soils. Under Decree No. 48/2011 Coll., codes with stagnosols most often fall into protection classes III to V, gleyed brown earths into classes II to IV.

For a house and garden, gleying is a warning about water. In spring and after rain, water may stand on the plot, roof water soaks away poorly and a cellar without good waterproofing may become damp. If you plan rainwater soakaways or construction, allow for a survey of infiltration and foundation conditions. Waterlogged farmland may have been drained with field drains; whether a plot has any is explained under land drainage.

Watch out for

A BPEJ code describes the whole mapped unit, not a specific parcel. Under a house or in a garden the soil may have been altered by fill. Actual infiltration conditions can only be confirmed by an on-site survey.