Long‐term Changes in Soil Macro‐ and Micromorphological Properties Under the Influence of Peat Debris

Abstract

Summary Field morphological examination and thin section observations were made to document the effects of varying additions of acid peat debris to a mineral topsoil after a period of 25–30 years. Additions up to 3 cm improved soil physical properties and faunal activity relative to the unamended topsoil. Additions of 5–8 cm caused acidification, structural alteration and iron mobilization. Further additions, ranging up to 30 cm, caused progressive increase in acidification, reduction, structural collapse, faunal inactivity, etc. The formation of thick humus coatings (organans) and diffuse subsurface impregnations in the mineral soil is highlighted.