Characteristics of fragipan B horizons developed on different parent material in North-Western Italy

ABSTRACT A Fragipan (Bx) is a soil horizon hard when dry and brittle when moist, that undergoes slaking upon water immersion, forming a barrier to roots and limiting land use. Brittleness and slaking depend on soil porosity and particle arrangement, but still no agreement exists on the inorganic components responsible for such arrangement. We hypothesized that the same kind of particle arrangement may originate from different soil components, ultimately depending on the lithology of parent material, and evaluated the soil and clay characteristics that best differentiate Bx from B horizons. Thirty-six samples were taken from Typic Fragiudalfs developed on the two sides of an alluvial fan characterized by different amounts of ultramafic materials. Discriminant Analysis evidenced that pedogenic Fe oxides were fundamental in discriminating Bx from B horizons on pure ultramafic parent material, while clay mineralogy was more important in soils with less ultramafic materials. In the first case, the association between clay minerals and self-assembling oxides systems may lead to brittleness, while in the second case the higher abundance of kaolinite may contribute to weak associations between pH-dependent sites and negatively charged surfaces. The only common feature to fragipans on both river sides was a higher degree of weathering.

[1]  B. Hajek,et al.  Mineral Occurrence in Soil Environments , 2018, SSSA Book Series.

[2]  D. Dent.  International Soil Reference and Information Centre (ISRIC) , 2017 .

[3]  E. Bonifacio,et al.  Contrasting environmental memories in relict soils on different parent rocks in the south-western Italian Alps , 2016 .

[4]  V. Melo,et al.  Clay mineralogy and genesis of fragipan in soils from Southeast Brazil , 2015 .

[5]  R. Bryant.  Physical Processes of Fragipan Formation1 , 2015 .

[6]  E. Knox,et al.  Identification, Role in Soil Taxonomy, and Worldwide Distribution of Fragipans1 , 2015 .

[7]  J. C. Ker,et al.  FORMAS DE FERRO, SILÍCIO E, OU, ALUMÍNIO NA GÊNESE DE FRAGIPÃS E HORIZONTES COESOS DOS TABULEIROS COSTEIROS , 2015 .

[8]  Jones Arwyn,et al.  World reference base for soil resources 2014International soil classification system for naming soils and creating legends for soil maps , 2015 .

[9]  M. Freppaz,et al.  Early stages of soil development on serpentinite: the proglacial area of the Verra Grande Glacier, Western Italian Alps , 2015, Journal of Soils and Sediments.

[10]  J. Bockheim,et al.  Soils with fragipans in the USA , 2013 .

[11]  G. Falsone,et al.  Influence of serpentine abundance on the vertical distribution of available elements in soils , 2013, Plant and Soil.

[12]  W. Szymański,et al.  Origin of reversible cementation and brittleness of the fragipan horizon in Albeluvisols of the Carpathian Foothills, Poland , 2012 .

[13]  I. Daniells.  Hardsetting soils: a review , 2012 .

[14]  G. Falsone,et al.  The effect of clear cutting on podzolisation and soil carbon dynamics in boreal forests (Middle Taiga zone, Russia) , 2012 .

[15]  M. Wilson,et al.  Location and expression of fragic soil properties in a loess-covered landscape, Southern Illinois, USA , 2010 .

[16]  Anònim Anònim.  Keys to Soil Taxonomy , 2010 .

[17]  G. Falsone,et al.  Pore‐size distribution and particle arrangement in fragipan and nonfragipan horizons , 2009 .

[18]  Mohammed Baalousha,et al.  Aggregation and disaggregation of iron oxide nanoparticles: Influence of particle concentration, pH and natural organic matter. , 2009, The Science of the total environment.

[19]  Z. Hseu,et al.  Weathering sequences of clay minerals in soils along a serpentinitic toposequence , 2007 .

[20]  G. Corti,et al.  Clues to the genesis of a discontinuously distributed fragipan in the northern Apennines, Italy , 2007 .

[21]  M. Forno,et al.  La successione stratigrafica del settore destro del Conoide di Lanzo e il suo significato per l’utilizzo del territorio. , 2007 .

[22]  Deutsche Ausgabe.  World Reference Base for Soil Resources 2006 , 2007 .

[23]  Park,et al.  Fragipan Formation within Closed Depressions in Southern Wisconsin, United States , 2006 .

[24]  Yu-Hsing Wang,et al.  Structure characteristics and mechanical properties of kaolinite soils. I. Surface charges and structural characterizations , 2006 .

[25]  G. Falsone,et al.  DESTABILIZATION OF AGGREGATES IN SOME TYPIC FRAGIUDALFS , 2006 .

[26]  M. Wilson,et al.  Weathering of the primary rock-forming minerals: processes, products and rates , 2004, Clay Minerals.

[27]  Robert Charlier,et al.  Chemo–mechanical interactions in clay: a correlation between clay mineralogy and Atterberg limits , 2004 .

[28]  M. Aide,et al.  FRAGIPAN GENESIS IN TWO ALFISOLS IN EAST CENTRAL MISSOURI , 2002 .

[29]  L. Norton,et al.  Effect of exchangeable Mg on saturated hydraulic conductivity, disaggregation and clay dispersion of disturbed soils , 2002 .

[30]  Mozart Martins Ferreira,et al.  Revista Brasileira de Ciência do Solo , 2000 .

[31]  Cheng Dong,et al.  POwderX: Windows-95-based program for powder X-ray diffraction data processing , 1999 .

[32]  D. P. Franzmeier,et al.  Role of Free Silicon, Aluminum, and Iron in Fragipan Formation , 1999 .

[33]  C. Shang,et al.  Organic Matter Stabilization in Two Semiarid Tropical Soils: Size, Density, and Magnetic Separations , 1998 .

[34]  L. P. van Reeuwijk,et al.  Procedures for soil analysis , 1995 .

[35]  D. P. Franzmeier,et al.  Clay mineralogy and chemistry of argillic horizons, fragipans, and paleosol B horizons of soils on a loess-thinning transect in southwestern Indiana, USA , 1994 .

[36]  R. Payton.  Fragipan formation in argillic brown earths (Fragiudalfs) of the Milfield Plain, north‐east England. III. Micromorphological, SEM and EDXRA studies of fragipan degradation and the development of glossic features , 1993 .

[37]  R. Payton.  Fragipan formation in argillic brown earths (Fragiudalfs) of the Milfield Plain, north-east England. II. Post Devensian developmental processes and the origin of fragipan consistence , 1993 .

[38]  U. Schwertmann.  Relations Between Iron Oxides, Soil Color, and Soil Formation , 1993 .

[39]  F. Plana,et al.  How mudrock and soil physical properties influence badland formation at Vallcebre (Pre-Pyrenees, NE Spain) , 1992 .

[40]  R. Langohr.  Fragipans: Their occurrence, classification, and genesis , 1991 .

[41]  K. Mcsweeney,et al.  Identification and genesis of fragipans in Ochrepts of North Central Wisconsin. , 1990 .

[42]  J. Torrent,et al.  Fragipan Bonding by Silica and Iron Oxides in a Soil from Northwestern Italy , 1989 .

[43]  A. Islam,et al.  Quantitative mineralogical analysis of some Bangladesh soils with X-ray, ion exchange and selective dissolution techniques , 1986, Clay Minerals.

[44]  C. Neyra.  Crystal Structures of Clay Minerals and Their X-ray Identification , 1983 .

[45]  J. Foss,et al.  Genesis of Maryland soils formed from serpentinite , 1982 .

[46]  D. P. Franzmeier,et al.  Silica Associated with Fragipan and Non-Fragipan Horizons1 , 1982 .

[47]  R. Langohr,et al.  Correlation between fragipans and permafrost with special reference to silty Weichselian deposits in Belgium and northern France , 1981 .

[48]  C. T. Hallmark,et al.  The Effect of Extractable Aluminum, Iron, and Silicon on Strength and Bonding of Fragipans of Northeastern Ohio , 1979 .

[49]  G. W. Petersen,et al.  Fragipans in Pennsylvania soils: a statistical study of laboratory data. , 1970 .