Salic Horizon - Soil Geography of the USA: A Diagnostic-Horizon Approach - page 215

Chapter 20
Salic Horizon

20.1 Introduction

The definition of the salic horizon in Soil Taxonomy (Soil Survey Staff 2010 ) started
with taxonomic placement problems from field mapping of soils with a high
temporary water table and abundant salts in NV in the late 1950s (Blackburn
2000 ). In the USA, these soils are unsuitable for agricultural uses unless they are
leached of salts, an expensive undertaking, especially if there is no natural outlet for
the drainage water. In the USA, most of these soils are used as rangeland, wildlife
habitat, or auto racing.
However, elsewhere in the world, soils with a salic horizon may be drained and
used for growing rice, barley, maize, and citrus crops. Saline soils comprise 2.6 %
of the world land surface, mainly in the Russian Federation, China, Argentina, Iran,
India, and Paraguay (Abrol et al. 1988 ). A key concern with the management of
soils with a salic horizon is salinization of soils and groundwater, the cost of which
has been estimated worldwide at $12 billion per year (Ghassemi et al. 1995 ). There
is a large body of data on saline soils in Eurasia (Abtahi 1977 ; Pfisterer et al. 1996 ;
Schofield et al. 2001 ; Alvarez Rogel et al. 2001 ; Khresat and Qudah 2006 ; Kotenko
and Zubkova 2008 ; Lebedeva et al. 2008; Sierra et al. 2009 ; Chernousenko
et al. 2011 ; Ubugunov and Ubugunova 2012 ). However, in the USA only a few
studies have addressed the distribution, classification, and genesis of soils with a
salic horizon (e.g., Reid et al. 1996 ; Joeckel and Clement 2005 ).
In Soil Taxonomy (Soil Survey Staff 2010 ), the requirements for a salic horizon
include (1) a thickness of 15 cm, (2) an electrical conductivity (EC) in a saturated

paste of 900. In the World

Reference Base for Soil Resources (IUSS Working Group WRB 2007 ), the salic
horizon must have a thickness of

30 dS/m, and (3) the product of EC and thickness of

15 cm, an EC of 15 dS/m, and the product of

Bockheim, J.G., Hartemink, A.E. 2013. Salic horizons in soils of the USA. Pedosphere
23(5):600-608. Acknowledgment is given to Elsevier Publishers for allowing a revision of
this article to be published herein.