الفهرس 
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Abstract
The current investigation aims to study the pedological
characteristics of some desertic soils of the northern part of Egyptian
Eastern Desert. The studied area is bounded by longitudes 310 30’ and
32” 30’ East and latitudes 30° 00’ and 30° 31 t North. It is characterized
by the presence of three geomorphic units, i.e., old deltaic plain,
structural plain and coastal plain. To get more soil information on such
area, 13 soil profiles were selected to represent the prevalent three
geomorphic units. Soil profiles were morphologically described and their
physical, chemical and sand mineralogical properties were evaluated.
The main results could be briefly summarized as follows:
a. Physical and chemical properties:
I. Soil texture ranges between sandy clay loam and sand in both the old
deltaic plain and the structural plain soils, while it ranges from clay to
sand in the coastal plain soils.
2. Soil gravel content reaches 1.25-26.51 %, 7.69-37.12% and 1.46-
44.14 % of soil components in the old deltaic plain, the structural plain
and the coastal plain soils, respectively. Thus, it appears to change
soil texture that becomes gravely sand. gravely loamy sand, gravely
sandy loam in layer attains 20% gravel or more. It is not detected in
profile 2 and in the deepest layer of profiles 3 and 10.
3. Calcium carbonate is found in a content of 0.22-5.70%, 5.70-22.70%
and 0.22-32.60% for soils of the old deltaic plain, the structural plain
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and the coastal plain, successively.
4. Gypsum content is 0.02-1.72%,0.03-1.72% and 0.01-10.25% of soil
components in soils of the old deltaic, the structural and the coastal
plains, respectively. It is not detected in the deepest layer of profiJe I
and the surface [ayers of profiles 2 and 7.
5. Organic matter content is generally very low and ranging between
0.07 and 0.23 % of soil components. That is due to the high
temperature and the prevailing aridity of the area.
6. Soil reaction is slightly alkaline to alkaline as shown by pH values
which range from 7.4 to 8.4 in the studied soils.
7. Soil salinity ranges from non saline to extremely saline as electrical
conductivity values (Ee) range widely from 1.50 to 97.44 dSlm.
8. Soil sodicity ranges from non sodic to sadie as exchangeable sodium
percent (E.S.P.) ranges from 3.51 % to 36.33% of cation exchange
capacity.
9. Soluble cations follow the orders of Na” or Ca”” > Mg++ > K+ in
the old deltaic soils and Na” > Ca” ” > Mg” ” > K+ in both soils of
the structural and the coastal plains. Soluble anions usually follow the
orders of CI- or S04 = > HC03- in both soils of the old deltaic and the
coastal plains and CI- > S04 = > HCOJ’ in the structural plain soils.
C03 = is not detected in the studied soil profiles.
10. Cation exchange capacity (C.E.C.) values fall in the range of 1.45-
. 19.12, 3.30-19.10 and 2.85-31.93 m.e.llOO g soil in soils of the old
deltaic, the structural and the coastal plains, respectively. C.E.C.
depends on clay plus silt and organic matter contents. Exchangeable
- --- --- -_. - .__._. --
--- .._.. -- _.
- -’- ,-- - ’_ .. _-------
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calcium is the dominant cation in the studied soil profiles and is
followed by Mg” ” or Na”, while K+ is the least abundant.
b. Mineralogy of the sand fraction:
1. Light minerals:
The mineralogical examination of the sand fraction shows that
quartz predominates the light minerals content and constitutes more than
95.00 %. Other associated minerals are orthoclase, plagioclase and
microcline which are detected in minute amounts.
2. Heavy minerals:
Heavy minerals are dominated by opaques. Non opaques were
dominated by amphiboles, pyroxenes, epidote and zircon, while rutile,
tourmaline, garnet, staurolite and biotite are detected in few amounts and
the remaining minerals are of less pronounced occurrence or not detected.
c. Uniformity of soil parent material:
This is tackled through heavy minerals and weathering ratios.
Distribution of resistant minerals and weathering ratio indicates that the
studied soils are heterogenous either due to their multi-origin or due to
the subsequent variations along the course of sedimentation and therefore
the studied soils are considered young from the pedological viewpoint.
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d. Grain size analysis and media of transportation:
Statistical size parameters indicate that water, wind and the
combined action of both water and wind are the main factors affecting
transportation and deposition of the soil materials. Thus, there is a maltidepositional
regime, as well as, a markedly variation in sediments
constituting soi Is of the considered area.
e. Soil classification:
According to the Soil Taxonomy (USDA, 1975), the obtained soil
classification could be introduced as follows:
I. Order: Entisols.
Suborder: Psanunents.
Great group: Torripsamments.
(Profiles 2 and 13).
Suborder: Orthents.
Great group: Torriorthents.
(Profiles 1, 3, 4, 5, 6, 7 and 12).
2. Order: Aridisols.
Suborder: Orthids.
Great group: Calciorthids.
(Profiles 8, 9 and 11).
Great group: Gypsiorthids.
(Profile 10).
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f. Land evaluation:
Tentatively evaluation shows that:
1. According to the Storie Index Rating system:
a. Soils represented by soil profiles 1, 2, 3, 5, 7, 9 and 13 are
poor soils.
b. Soils represented by soil profiles 4,6, 8, 10, 11 and 12 are very
poor soils.
2. According to the Sys and Verheye system:
a. Soils represented by soil profile 9 are moderately suitable for
irrigation.
b. Soils represented by soil profiles 1, 3, 4, 5, 6,7,10,11,12 and
13 are marginal suitable for irrigation.
c. Soils represented by soil profiles 2 and 8 are currently not
suitable for irrigation but its limitations can be corrected.
It is recommended that an economical study should proceed for the
evaluation of the whole area.