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Atlas of Jordan

Myriam Ababsa

Chapter one - Constraints and Resources

The Soils of Jordan

Bernhard Lucke, Feras Ziadat et Awni Taimeh

Texte intégral

1Up to now, no nation-wide and reliable soil map exists for Jordan that is up-to-date although several soil surveys have been conducted. The first general soil map for Jordan – now outdated and using old terminology (see Reifenberg 1947) – was prepared by the Food and Agriculture Organisation (FAO) of the United Nations (Moorman 1959). Other soil surveys were done by the Wadi Ziqlab soil survey (Fisher et al. 1966), by the Baqa’a valley survey (West 1970), by the Zarqa river dam project (GTZ 1986), by the National Soil Map and Land Use Project , and by the Jordan Valley soil survey (GITEC 2005). These surveys used different classification systems (table I.4). The German Geological Mission, which carried out the first national survey of geology, also produced a soil map (Bender 1974), that for some time was the only available nation-wide soil map despite its uncommon terminology and limited detail (see this soil map in RGCJ 1984). The National Soil Map and Land Use Project produced the nation-wide soil database Jordan Soil and Climate Information System (JOSCIS) and maps at different scale for selected areas, but not a simplified nation-wide map. Neither the database nor the maps were adequately published so far. Based on the JOSCIS database information, we drew a strongly simplified nation-wide soil map (fig. I.17) that presents the dominating soil suborders of the respective areas, which we consider the most accurate, though simplified, nation-wide soil map of Jordan that is available until now. It should be noted that some of the soil names that were determined according to the 4th edition of the USDA soil taxonomy (1990) are now obsolete and should be replaced by the classifications according to the 11th edition (USDA 2010) as explained in the text. In the future, the World Reference Base for Soil Resources (WRB) could be used in Jordan too.

Table I.4  — Comparative soil names used during Jordan’s major soil surveys.

Reifenberg, 1947; Moorman, 1959; Bender 1974

Fisher et al., 1968

GTZ, 1986

West, 1970; USDA, 1990 (used in the NSM&LUP, 1993 and by GITEC)

WRB, 2007

Terra Rossa Red
Mediterranean Soil
Basalt Soil

Terra Rossa
Brown Limestone Soil
Brown Slope Soil
Brown Cherty Soil
Brown Bench Soil

Red And Dark
Cracking Clays

Inceptisol (Xerochrept)
Vertisol (Chromoxeret)
Alfisol (Xeralf)
Entisol (Xerothent)

Vertisol (Vertic, Calcic, Chromic, Luvic, Haplic, Cambic)
Luvisols were not confirmed in Jordan.

Mountain Marl
Regosols and Lithosols

Grey Limestone
Soil Grey-White Slope Soil
Yellow Brown Slope Soil

Clay Loams With a Surface Crust

Inceptisol (Xerochrept)
Entisol (Torriorthent, Torripsamment)
Aridisol (Camborthid, Calciorthid)


Yellow Mediterranean Soil
Chernozemic-like Soils


Red And Brown Non-Cracking Clays

Inceptisol (Calcixerollic Xerochrept)


Yellow Soil
Yellow Steppe
Soil Grey Desert Soil



Entisol (Torriorthent, Torripsamment)
Aridisol (Camborthid, Calciorthid)


Jordan Valley soils
Alluvial Soils

Alluvial Soil


Entisol (Torrifluvent)


Gypsum Soils



Aridisol (Salorthid, Gypsiorthid)


Comparative overview of roughly corresponding soil names used during Jordan”s major soil surveys and their equivalent names in the World Reference Base for Soil Resources (WRB), and referring to our map drawn on the basis of the database of the National Soil Map and Land Use Project of Jordan (see fig. 1.17). However, table neither provides a complete summary of soils occurring in Jordan, nor can the names of the different classification systems directly be «translated» from one to another system (Source: B. Lucke).

Figure I.17  — Jordan Map of Soils.

Figure I.17  — Jordan Map of Soils.

2The distribution of soils in Jordan follows closely the climate and topography. Specific soil orders can be found within the dry and hot subtropical, subhumid-semiarid, semiarid-arid, and arid regions. The soils of the dry and hot subtropical Jordan Valley are dominated by the soil orders Inceptisols and Entisols. The main Great Groups are: Ustochrepts (the suborder Ochrepts is now obsolete; these soils are mainly part of the Ustepts and Udepts soil suborders in the 11th edition), and Ustifluvents north of the area which receives more than 250 mm of annual rainfall, while the area with less than 250 mm rainfall and north of the Dead Sea is dominated by Torrifluvents. The area south of the Dead Sea to Aqaba is dominated by Torripsamments and Torrifluvents (Taimeh 2012) (table I.5).

Table I.5  — Strongly simplified description of the soil orders present in Jordan.

USDA soil order/great group



Soils with aridic (i.e. dry) moisture regime, weak soil development, often enrichment of calcium carbonate and/or gypsum or other salts






Deep cracking soils, mostly red, very high clay content, shrink and swell with moisture variations (mixing the solum)



Very weakly developed, initial soils, mostly A-C horizons or no horizons, sometimes similar to crushed bedrock, shallow and/or rich in stones or gravel





Moderately developed soils, in Jordan mostly red, with clay-rich B-horizon, often rich in primary or secondary calcium carbonate


3The sub-humid to semiarid (Mediterranean) climate in the north-west (locally known as Highland region) is dominated by three soil orders. The first one is Inceptisols which occupy level slopes, with the main Great Group Xerochrepts (USDA 1990), or Haploxerepts (USDA 2010). The second suborder is Entisols, with the main Great Group Xerorthents, which occupy areas with steep slopes. The third order is Vertisols, with the main Great Group Chromoxerets (USDA 1990), or Chromic Haploxererts (USDA 2010). Vertisols can be found in areas with more than 250 mm rainfall and slopes of less than 6% (Taimeh and Khresat 1988).

4The semiarid-arid steppe region is dominated by Inceptisols, Entisols, and Aridisols. Inceptisols of this region are silty soils with high carbonate and low organic content, while Entisols are shallow soils which occupy slopes steeper than 10%. Aridisols and Entisols dominate the arid region. The main Great Groups of Aridisols are: Calciorthids, Camborthids, Gypsiorthids and Paleorthids (USDA 1990), or Haplocalcids, Haplocambids, Haplogypsids, and Petrocalcids (USDA 2010). Entisols in the arid regions are weakly developed soils, which can be found on steep or eroded slopes, or in areas dominated by sandy parent rocks. They frequently resemble crushed bedrock which also determines the colour (Lucke and Bäumler 2007). The main Great Groups include: Torriorthents and Torripssaments (USDA 1990, 2010), and Torrifluvents where periodic floods in basins (Qa’as) create mudflats, or in buried old water ways that filled with sediments.

5Soil properties mirror the variability of the current climate, which varies from sub-humid Mediterranean climate in the northwestern part of the country to arid desert climate in the East over a distance of less than 100 km. They also reflect the relief (Ziadat et al. 2010). Buried paleosols, however, point to different rainfall distributions in the past. Paleosols are extensively found in the today semiarid-arid and arid regions, mostly buried below a thick silty layer. This silt could have formed as a result of rock weathering, or represents Loess (Cordova 2007), covering about 10% of the country and appearing as a white strip in north-south direction on satellite images east of the Highland region.

6An important part of Jordan’s soils formed on limestone or basalt and shows red colour (Terra Rossa or Red Mediterranean Soil in old classification systems; Vertisols and Incepitsols orders due to their high clay and oxides contents in the USDA soil taxonomy). Their genesis indicates that they were influenced by a sequence of climatic changes, especially after the formation of the Jordan Rift Valley (Khresat and Taimeh 1998). As well, slope and colluvial activities (erosion by water) seem to have played a most significant role in their formation. The presence of soils with deep profile and high clay content rich in oxides and clay films indicate that part of these soils was formed in a more humid climate (Taimeh 1984). This is further supported by buried paleosols in the steppe and desert, even in areas where the current average annual rainfall is less than 30 mm. However, the genesis of Terra Rossa is not completely clarified: it is discussed whether it is mainly derived from the bedrock, from aerosols, or forms by metasomatic processes (Lucke 2008, 56-132). Isovolumetric replacement could be confirmed for some Terrae Rossae in north-west Jordan, indicating that the genesis of these soils could take place during shorter periods and require less rock dissolution or aerosols than previously thought.

7Soil fertility generally varies from one soil order to another. The most fertile soils are those of the Inceptisols and Vertisols, due to their high clay content and high caption exchange capacity. However, these soils suffer from low organic matter and nitrogen contents, and sometimes iron, zinc and phosphorus deficiency due to high carbonate content. The Vertisols induce physical stress on plant roots due to cracking which is driven by swelling and shrinking due to moisture variations. Therefore, they are suitable only for field crops, while trees are not recommended. Slopes are often covered by Xerorthents, which are generally shallow soils and recommended for forest plantation. Even if irrigation water is available, Aridisols in the dry regions pose various problems for cultivation that result from high carbonate, gypsum or salt contents. Entisols are difficult to cultivate as well because they are dominated by sandy, gravelly, stony, or shallow substrate (Taimeh 2012). Although some agricultural studies concluded that the cultivated soils in Jordan were strongly eroded and degraded due to man-made mismanagement in the past (Lowdermilk 1944), historic erosion-sedimentation cycles in Jordan might in fact relate more strongly to climatic fluctuations (Lucke 2008). Overall erosion in Transjordan might not have exceeded the geological rate and the country could be in the stable state of completed erosion (Ionides and Blake 1939; NSM&LUP 1993, 43).

Table des illustrations

Titre Figure I.17  — Jordan Map of Soils.
Fichier image/jpeg, 199k

© Presses de l’Ifpo, 2013

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