Proposal for a new diagnostic horizon for WRB Anthrosols Carmelo Dazzi ⁎, Giuseppe Lo Papa, Vanessa Palermo Dipartimento di Agronomia Ambientale e Territoriale – Università di Palermo Viale delle Scienze, 90128 Palermo, Italy abstract article info Article history: Received 19 January 2009 Received in revised form 10 March 2009 Accepted 13 March 2009 Available online 16 April 2009 Keywords: Anthropedogenic processes Diagnostic horizons WRB qualifiers Geomiscic horizon Soil classification To investigate man's role in the creation and evolution of soils in areas of large scale farming, and to investigate the main morpho-descriptive aspects of the related soils, a survey was carried out in south eastern Sicily, Italy, where, as common to other regions of the Mediterranean basin, there are wide areas with anthropogenic soils due to large scale farming activity. The complex genesis pattern of these anthropogenic soils, which shows a double sequence of man-made horizons, sideways oriented to the soil surface, does not allow their classification as Technosols, because their composition is not dominated or strongly influenced by artefacts or human-made materials as is the case for Technosols. According to the principles of the WRB (World Reference Base for Soil Resources), these soils should be regarded as being within the Anthrosols reference soil group (RSG). For their classification, the “geomiscic” horizon, not listed among the diagnostic horizons of the WRB, is proposed as a new diagnostic horizon for the Anthrosols RSG. The geomiscic horizon can be succinctly defined as “a horizon that develops when a layer, at least 30 cm thick of different kinds of earthy materials, is added to the soil using earthmoving equipment. For farming purposes this layer is subsequently deeply mixed into the underlying soil using heavy machinery. Its colour is related to the source materials and generally the layer is not parallel to the surface of the soil”. © 2009 Elsevier B.V. All rights reserved. 1. Introduction In recent decades man's role in soil formation has become a matter of great concern among soil scientists (Dudal et al., 2002). Man is now considered a soil-forming factor and anthrosolization is recognised as a soil-forming process (Bockheim and Gennadiyev, 2000; Bryant and Galbraith, 2003) that consists of a collection of geomorphic and pedological processes resulting from human activities. These human activities include deep working, intensive fertilization, the addition of extraneous materials, irrigation with sediment-rich waters and wet cultivation (Kosse, 1990). The genetic peculiarity of human-influenced soils, as well as their features and properties, was shown in several soil surveys carried out in various environments: urban areas (Short et al., 1986a,b; Agarkova et al., 1991; Burghardt, 1994a,b), mining areas (Ciolkosz et al., 1985; Indorante et al., 1992; Haering et al., 2005), iron and steel production areas (Buondonno et al., 1998), agricultural areas (Dazzi and Monteleone, 1999, 2007), forested areas (Andres-Abellan et al., 2005) and recreational areas (Arroyo and Iturrondobeitia, 2006). The anthropogenic soil-forming processes, relating to long-term agricultural use, influence soil properties over hundreds of years. In the case of soils affected by land use changes in large scale farming, the anthropogenic processes can be extremely fast-acting (Dazzi and Monteleone, 2007). Over the last few years, such anthropedogenic processes have left a mark not only on many traditional vine-growing areas of Mediterranean Europe, where the capital income derived from vineyard cultivation is substantial (Dazzi et al., 2004; Pla Sentis et al., 2004; Coulouma et al., 2006; Costantini and Barbetti 2008), but also on new vine-growing areas outside Europe (Fairbanks et al., 2004). This study, carried out on a large scale vine-growing area in south eastern Sicily, Italy, was aimed at: i) illustrating the anthropic processes that, in a short period of time, have characterized the formation of anthropogenic soils and, ii) following the WRB rules (IUSS Working Group WRB, 2006), proposing a new diagnostic horizon to classify such anthropogenic soils within the Anthrosols group. 2. Study area The study area is located in the Acate river valley, south eastern Sicily, Italy (Fig. 1). Here, during the late 1970′s, vineyards spread copiously and produced a large increase in capital income (Lo Verde, 1995). At present, most of the farms in the area are vine-growing. The climate is Mediterranean, with average monthly temperatures that reach a maximum in August (25–26 °C) and a minimum in January (10–11 °C) and with an average annual rainfall of about 450 mm. From a geomorphological point of view, the landscape is characterized by a Geoderma 151 (2009) 16–21 ⁎ Corresponding author. Tel.: +3909123862211; fax: +39 09123862239. E-mail address: dazzi@unipa.it (C. Dazzi). 0016-7061/$ – see front matter © 2009 Elsevier B.V. All rights reserved. doi:10.1016/j.geoderma.2009.03.013 Contents lists available at ScienceDirect Geoderma journal homepage: www.elsevier.com/locate/geoderma