الفهرس 
Material and methodsOnly 14 pages are availabe for public view
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Abstract
The aim of the current investigation is to evaluate some soils located in
north Delta for the agricultural purpose. These soils occupy an area runs
generally from Damietta branch in the east to Rosetta branch in the west,
penetrating the old cultivated lands in the south and stretching between longitudes
30° 20- and 31° 50’ east and latitudes 31° Ifrand 31° 36- north.
The area is characterized by three geomorphic units, namely, coastal
barrier plains and beaches, fluvio marine deposits and recent Nile alluvial
deposits. To fulfill the purpose of this study, thirty one soil profiles were dug
along five transects within the studied area to represent all the possible variations
between the soils consisting the three geomorphic units. Soil profiles were
morphologically described and subjected to the physical and chemical analyses
required to attain qualitative and quantitative evaluation for the studied area. The
following is a brief summary of the obtained results:
1- Soils of coastal barrier plains and beaches, fluvio marine deposits and
recent Nile alluvial deposits were sandy, clay and clay loam to clay,
respectively.
2- CaC03 content ranged from 0.08 to 0.84; 0.17 to 8.38 and 0.22 to 2.94%
whereas gypsum content varied from 0.11 to 3.65; 0.11 to 2.09 and 0.09
to 0.52 % in the soils of coastal barrier plains and beaches, fluvio marine
deposits and recent Nile alluvial deposits, respectively.
3- Organic matter content was very low in all soil profiles and ranged from
0.06 to 0.72; 0.55 to 2.40 and 0.10 to 2.66% in the soils of coastal
barrier plains and beaches, fluvio marine deposits and recent Nile alluvial
deposits, respectively.
4- Bulk densities ranged from 1.67 to 1.78; 1.14 to 1.51 and 1.20 to 1.60
g/cnr’ in soils of the abovementioned three geomorphic units, respectively.
5- Total porosity ranged from 32.32 to 36.98; 44.49 to 58.09; and 40.30 to
55.71 % in the soils of the respective three geomorphic units.
6- Hydraulic conductivity varied widely from one geomorphic unit to
another. It fluctuated between 11.375 and 19.960 in soils of the coastal
barrier plains and beaches; 0.025 and 0.614 in the fluvio marine deposits
and 0.053 and 2.285 cm/hr in the soils of the recent Nile alluvial deposits.
7- Soil moisture contents at field capacity, wilting point and available water
increased by increasing silt, clay and organic matter contents. The highest
values of moisture contents at field capacity, wilting point and available
water were 45.73, 25.85 and 21.07% in the soils of fluvio marine
deposits, while the lowest ones were 6.14, 3.28 and 2.02 % in the soils of
coastal barrier plains and beaches.
8- Soil salinity differed widely from one locality to another. EC values
ranged between 1.3 and 78.9; 1.1 and 27.8 and 1.1 and 3.7 in the soils
of the coastal barrier plains and beaches, fluvio marine deposits and recent
Nile alluvial deposits, respectively. Soluble cations were dominated by
Na” followed by Mg’ ”, Ca” ” and K+ in the soils of the coastal barrier
plains -and beaches and fluvio marine deposits. In the soils representing
the recent Nile alluvial deposits, Ca” ” dominated over magnesium.
Soluble anions generally followed the descending order: CI” > 5°4-- >
HC03-· C03-- was not found in any detectable amount.
9- Soil reaction of the studied soils (pH) was slightly to moderately alkaline
conditions of all the soils representing the different geomorphic units
where these values fluctuated between 7.4 and 8.2.
10- SAR values ranged from 2.1 to 93.1; 1.6 to 69.1 and 1.3 to 9.7 in the
soils representing the coastal barrier plains and beaches, fluvio marine
deposits and recent Nile alluvial deposits, respectively.
11- The values of cation exchange capacity were in the order of fluvio marine
deposits> recent Nile alluvial deposits> coastal barrier plains and
beaches and had the averages of 48.80, 35.08 and 2.38 me/IOOg soil,
respectively. The exchangeable cations of the soils of coastal barrier
plains and beaches and fluvio marine deposits followed the descending
order: Mg’ ” > Cat” > Na” > K+. However, calcium dominated over
magnesium in the soils of the recent Nile alluvial deposits. ESP values of
soils representing the recent Nile alluvial deposits were less than 15%
whereas the ESP values of the soils representing the other two geomorphic
units exceeded 15% (except for the soil profiles No.2, 8 and 13 in the
coastal barrier plains and beaches and proftles No 4, 9, 10 and 17 in the
fluvio marine deposits.
12- Total nitrogen content ranged from 39.7 to 272.2; 179.8 to 1655.8 and
124.7 to 1740.2 with the averages of 96.9; 556.3 and 555.6 ppm in the
soils of coastal barrier plains and beaches, fluvio marine deposits and
recent Nile alluvial deposits, respectively. Highly significant positive
correlations were established between total N and organic matter content
of all the soils representing the three geomorphic units. Available
nitrogen ranged between minimum values of 3.5; 21.4 and 22.9 and
maximum ones of 32.9; 167.8 and 175.1 and averaged 14.7; 61.6 and
63.9 ppm in the soils of the respective three geomorphic units. Highly
significant positive correlations were found also between total and
available N contents of the soils representing the three geomorphic units.
13- Total phosphorus content ranged from 172.5 to 401.2; 683.4 to 1312.2
and 505.9 to 1148.2 with averages of 280.8; 863.7 and 761.9 ppm in the
soils of coastal barrier plains and beaches, fluvio marine deposits and
recent Nile alluvial deposits, respectively. Highly significant positive
correlation were established between total P and clay content in the soils
of the three geomorphic units. Available P ranged from 1.3 to 8.7; 4.5
to 28.4 and 4.8 to 23.5 corresponding to averages of 4.0, 12.1 and 12.6
ppm in the soils of the respective three geomorphic units. Significant
negative correlation was found between available P and soluble Mg’ ” in
the soils representing the coastal barrier plains and beaches.
14- Total potassium content ranged from 2.1 to 7.1; 17.4 to 30.6 and 12.8 to
23.9 with averages of 3.9,24.1 and 18.9 me/lOOg in the soils of coastal
barrier plains and beaches, fluvio marine deposits and recent Nile alluvial
deposits, respectively. Highly significant positive correlations were found
between total K and soil clay content of all the geomorphic units.
Available K content ranged from 0.09 to 0.88; 0.74 to 5.0 and 0.38 to
1.41 and averaged 0.39; 2.46 and 0.91 mellOOg in the soils representing
the respective three geomorphic units. Significant positive correlations
were established between available K and soil clay content of all the
geomorphic units.
15- Total iron content ranged from 1.12 to 2.15; 5.30 to 6.95 and 4.13 to
6.60% in the soils of coastal barrier plains and beaches, fluvio marine
deposits and recent Nile alluvial deposits, respectively. The corresponding
computed weighted mean of total Fe ranged from 1.15 to 2.00; 5.52 to
6.76 and 4.89 to 6.37%. Highly significant positive correlations were
found between total Fe and each of clay, sum of clay + silt and organic
matter content. In contrast, total Fe was negatively highly significantly
correlated with soil sand content of all the geomorphic units. The DTPAextractable
Fe ranged from 2.1 to 5.1; 2.1 to 25.1 and 2.9 to 26;7 ppm
in the soils representing the respective three geomorphic units.
16- Total manganese content ranged from 73.5 to 187.4; 599.0 to 1143.0 and
483.0 to 976.0 ppm in the soils of coastal barrier plains and beaches,
fluvio marine deposits and recent Nile alluvial deposits, respectively. The
corresponding computed weighted mean ranged from 83.07 to 169.78;
759.17 to 1068.11 and 555.33 to 880.83 ppm. Total Mn was positively
highly significantly correlated with sum of clay + silt and negatively
highly significantly correlated with soil sand content of all the geomorphic
units. The DTPA-extractable Mn ranged from 0.5 to 4.7; 2.6 to 11.6 and
2.1 to 5.4 ppm in the soils representing the three geomorphic units,
respectively.
17- Total zinc content ranged from 38.9 to 68.9; 96.7 to 179.1 and 89.9 to
158.1 in the soils of coastal barrier plains and beaches, fluvio marine
deposits and recent Nile alluvial deposits, respectively. The corresponding
computed weighted mean ranged from 43.21 to 58.83; 98.15 to .164.68
and 99.01 to 154.48 ppm. Highly significant positive correlations were
established between total Mn and soil clay content of all the studied
geomorphic units. In contrast, total Mn was negatively highly
significantly correlated with soil sand content. The DTPA-extractable Mn
ranged from 0.2 to 1.6; 0.8 to 4.2 and 1.1 to 4.4 ppm in the soils
representing the three geomorphic units, respectively.
18- Total copper content ranged from 28.4 to 46.8; 69.4 to 92.4 and 62.1 to
88.5 ppm in the soils of coastal barrier plains and beaches, fluvio marine
deposits and recent Nile alluvial deposits, respectively. The corresponding
computed weighted mean ranged from 29.03 to 39.99; 69.65 to 87.47 and
66.60 to 85.98 ppm. Highly significant positive correlations were
established between total Cu and each of clay and sum of clay + silt. In
contrast, total Cu was negatively highly significantly correlated with sand
content of all the soils representing the three geomorphic units. The
DTPA-extractable Cu ranged from 0.1 to 1.1; 3.4 to 8.2 and 2.5 to 8.1
ppm in the soils representing the respective three geomorphic units.
19- Total boron content ranged from 12.5 to 38.1; 70.5 to llO.3 and 47.7 to
69.5 ppm in the soils of coastal barrier plains and beaches, fluvio marine
deposits and recent Nile alluvial deposits, respectively. The corresponding
computed weighted mean ranged from 13.34 to 32.74; 73.32 to 100.38
and 49.70 to 58.60 ppm. Total B was positively highly significantly
correlated with total soluble salts content of the soils of the coastal barrier
plains and beaches and fluvio marine deposits. The hot water soluble
boron ranged from 0.9 to 7.4) 1.0 to 7.1 and 0.5 to 1.5 ppm in the soils
representing the three geomorphic units) respectively.
20- Based on the abovementioned soil characteristics and recognized
agricultural limitations) qualitative land capability classification was
performed according to the USDA system (1973) and FAD framework of
land suitability classification (1976). Qualitative land capability
classification was also worked out following both the modified Storie
index (Nelson, 1963) and Sys and Verheye’s system (1978).
According to these systems) the soils of the studied area could be classified
as follows:
A. The area suitable for agriculture utilization.
1. Using the USDA system, an area equals 204449 feddans, representing
96.63 % of the studied area, is suitable.
2. Using the FAO system) an area equals 191949 feddans, representing
90.72 % of the studied area, is suitable.
3. Applying modified Storie index, the suitable area equals 120799
feddans, representing 57.09 % from the studied area.
4. Applying Sys and Verheye’s system, an area amounting to 142289
feddans, representing 62.25 % from the studied area, is suitable.
B. The non suitable area recorded with the different systems can be swnmarized
as follows:
1. Using the USDA system, the non suitable area equals 7141 feddans,
representing 3.37% of the studied area.
2. Using the FAO system, the non suitable area equals 19641 feddans,
representing 9.28% of the studied area.
3. Applying modified Storie index, an area equals 90791 feddans,
representing 42.91 % of the studied area, is non suitable.
4. Applying Sys and Verheye’s system, an area equals 69301 feddans,
representing 32.75 % of the studied area, is non suitable.
c. Results may suggest that the quantitative systems more suitable under the
Egyptian conditions, where theirresults are compatible with the studied area
conditions.
D. Sys and Verheye’s system, could be considered as favourable system under
the conditions prevailing in the soils of Egypt.
As a general conclusion, it can be said that the soils of north Delta vary
widely in their suitability for the agricultural purpose. A consequent detailed or
semi detailed survey is required to attain reliable evaluation for such a wide area.