PLACE OF HORIZONS IN THE NEW FRENCH REFERENTIEL PEDOLOGIQUE

In 1986 the ''Association Francaise pour l'Etude du Sol (A.F.E.S.)'' started a project to replace the former soil classification introduced in 1967 by the ''Commission de Pedologie et de Cartographie des Sols (C.P.C.S.)''. The new system owes much to advances made in the past twenty years and is the collective work of more than sixty scientists with additional material derived from various other sources. It conforms to the usually accepted morphogenetic approach, nevertheless two major innovations have been introduced: (i) the real objects under investigation are ''Soil Mantles''; (ii) the system is not hierarchical but typological. The ''Referentiel Pedologique'' (abbreviated as R.P.) is yet to be fully developed and a fourth version will be published in 1992. Nevertheless, his general principles are well defined and are explained below. The R.P. is based on four basic notions: ''Soil Mantles'', ''Solums'', ''Reference Horizons'' and ''References'' (fig. 1).