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5 Identification of the Taxonomic Class of a Soil |
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Typic Torripsamments). The key is only application to Aridisols and Entisols identified in Kuwait. Other countries in the GCC can develop their own national soil taxonomy books specific to soils identified in national surveys.
Keywords
Aridisols Entisols Argids Calcids Cambids Gypsids Salids
Taxonomic
5.1Introduction
The soil survey of Kuwait (KISR 1999a, b) was completed at two levels,
(i) Reconnaissance survey at family level of US Keys to Soil Taxonomy hierarchy and; (ii) Semi-detailed survey at soil series level (Soil Survey Staff 1999). During these two surveys, of twelve soil orders identified globally and described in the US Keys to Soil Taxonomy (Soil Survey Staff 2014) only two soil orders (Aridisols and Entisols) have been identified in the State of Kuwait. Therefore, Kuwait Soil Taxonomy is limited to soil taxa identified in Kuwait from Order-suborder-great group-subgroup-family level (KISR 1999a) and to Order-suborder-great group- subgroup-family-series level (KISR 1999b). The user of Kuwait Soil Taxonomy can assign a soil taxon to an in-depth described location by going through the key systematically, starting at the beginning and eliminating one by one all classes that include criteria that do not fit the soil in question until find the matched one. The key is only application to Aridisols and Entisols hierarchy identified in Kuwait. Other countries in the GCC can develop their own national soil taxonomy books based on the soils mapped within their national boundaries. Lately UAE has published United Arab Emirates Keys to Soil Taxonomy (Shahid et al. 2014) based on the results from three soil surveys (i) Dubai emirate (DM 2005), (ii) Soil Survey of Abu Dhabi Emirate (EAD 2009a, b) and Soil Survey of the Northern Emirates of UAE (EAD-MOEW 2012).
5.2Soil Orders Identified in Kuwait
Two soil orders “Aridisols & Entisols” have been identified in Kuwait. According to the Soil Survey of Kuwait (KISR 1999a, b) Aridisols are dominant (70%) soils in Kuwait compared to Entisols (30%) (Fig. 5.1).
5.2 Soil Orders Identified in Kuwait |
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Entisols
30%
Aridisols
Entisols
Aridisols
70%
Fig. 5.1 Relative distribution of soil map units in Aridisols and Entisols
5.2.1 Aridisols
Aridisols, are soils that do not have water available to mesophytic plants for long periods. In hot climate soil moisture is held at potentials less than permanent wilting point or if it is salty, or both. There is no period of 90 consecutive days when moisture is continuously available for plant growth (Eswaran and Reich 2005).
Aridisols is one of the twelve soil orders in US Soil Taxonomy (Soil Survey Staff 2014). Aridisols (from the Latin aridus, for “dry”, and solum) form in an arid or semi-arid climate. Aridisols dominate the deserts. The deserts occupy about one third of the Earth's land surface. Aridisols occupy approximately 12 percent of the Earth's ice-free land. Aridisols are low in organic matter, poor vegetation covers and are water deficient. Soil formation and development of diagnostic horizons (calcic, gypsic, argillic etc.) requires many years to develop. Accumulation of salts at surface is a common feature due to high evaporation and low leaching.