الفهرس 
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Abstract
SUMMARY
To study the effect of cultivation practies
on the properties of newly reclaimed soils, two
soils groupS were shosen at Nubariya region which
contains 5 to 17% calcium carbonate content, and
Ismailya region which contain 1 to 2% calcium
carbonate. Within each group, five soil profiles
were selected; one representing a virgin soil and
four representing different cultivation intervals,
one, two or three, five and ten years. Changes
in some soil physical and chemical properties were
recorded and evaluated.
Results obtained can be summerized as follows:
Soil Texture:
The textural classes of virgin soils at Nubariya
are in the range of loamy sand and sandy clay loam,
whereas that at Ismailya is sand. Soil under cultivation
at Nubariya were very loW in the clay fraction.
Some removal of clay fraction is might have occurred
upon cultivation. However, the decrease in clay
fractino is more pronounced in upper 20 cm layers
rather than the deeper ones and in soils at their
earlier stages of· cultivation rather than at their
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latter ones. On the other hand. higher clay contents
are generallY shown by the cultivated soils of
Ismailya compared with the virgin soil especiallY
in the surface layers.
Organic Matter:
The organic matter contents of Nubariya soils
tend to accumulate in the surface layers and gradually
decreased with depth. In cul~ivated soils. the
organic matter content waS hi~her. On the other
hand. the soils of Ismailya cfntain less organic
matter content as compared tOithose of Nubariya.
In cultivated soils the org nic matter content
of Ismailya soils is also highe than in the virgin
soil.
Carbonate Distribution:
The carbonate contents are in the range of
11.59 to 17.39% in the virgin soils of Nubariya
region. They tend to decrease in cultivated soils.
However. they are much lower decrease in soils
at their earlier stages of cultivation and in the
surface layerS. Very low contents of carbonates
are detected in the soils of Ismailya region which
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are in the ranqe of 0.70-1.30% in the virgin soils.
In cultivated soils, carbonates tend to be slightly
higher.
Total Soluble Salts:
The Ec of the virgtn soils at Nubariya are
in the range of 2.5 to 5.98 ds/m. In cultivated
soils contents of soluble salts were lower reaching
minimum values in soils at: two years of cultivation.
In soils of five years· of cultivation the salts
tend towrds the accumulation. This holds true for
the surface as well as the deeper layers. On the
other hand the soils of Ismailya region are generally
characterized by less salt contetns with a slight
increase in cultivated soils.
Distribution of Soluble Anions:
The soluble sulphate are the dominant anions
in all layers of .....- ..t.h.e virgin soils at Nubariya •
In soils cultivated for 3
bicarbonates and chlorides
cultivated for 10 years
dominant.
to 5 years both soluble
were dominant. In soils
the soluble sulphates was
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The individual distri.bution of soluble anions
in the virgin soils at Ismailya region show that
characteristic pattern, in which chlorides dominate
the other soluble anions in the uppermost
layers. Deeper in the soil profile the sulphates
become the dominant anions followed by bicarbonates.
In cultivated soils the chlorides ar.d bicarbonates
were dominant.
Distribution of Soluble cations:
The distribution of soluble cations in the
virgin soil at Nubariya region show that the soluble
sodium is the dominant cation followed by calcium.
The soluble magnesium is lower than both sodium
and calcium in all layers and soluble potassium
is lowest. In soils having one and two years of
cultivation much of the soluble sodium. seems to
have been leached out of soil profile and soluble
calcium was dominant. In soils having 5 and 10
years of cultivation soluble calcium and sodium
become in equal quantiti~s and they both dominate
soluble cations. In the virgin soil of Ismailya,
the soluble calcium is the predominant cations
in most soil layers, espe<:ially in the surface,
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8”~l
followed by soluble sodium and magnesium. In cultivated
soils soluble sodium tends to accumulate and appro
xi
-
mately equals to soluble calcium.
Cation Exchange Capacity and Exchangeable Cations:
The cation exchange capacity of the virgin
soils is 19.83 and 15.57 me/1009 for surface and
subsurface layers respectively at Nubariya region.
In the soils cultivated for one year cation exchange
capacity increases up to 21.85 and 16.85 me/1009
for both surface and subsurface layers respectively.
The values of exchange capacity for Nubariya soils
tend to be high for fine-textured soils and low
for coarse-textured ones. They were higher in cultivated
soils. The increase of CEC on cultivation,
is more pronounced in the surface rather than the
deeper layers. The distribution pattern of individual
exchangeable cations of Nubariya soils is in the
order of Ca>mg >Na>K.
The cation exchange capacity of Ismailya region
also’ increases in cultivated soil. The distribution
pattern of exchangeable cations of Ismailya soils
is similar to that of Nubariya soils.
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Soil Bulk Density:
The soil bulk density of the virgin soil is
in range of 1.49 to 1.56 g/cm3 and of 1.74 to
1.89 g/cm3 for Nubariya and· Ismailya soils respectively.
Within the soil profile the bulk density
values in both soils tend to increase with depth.
Also bulk densities tend to decrease on cultivation
in both surface and subsurface layers for both
soils. However, the decrease in bulk density upon
cultivation is more pronounced in the surfac~ layerS
rather than the deeper ones. The bulk densities
of Nubariya soils are lower than that those of
rsmailya soils.
Total porosity and Void Ration
The total porosity of virgin soil and that
of the one-year cultivated soils is higher for
Nubariya than for Ismailys soils. In soils cultivated
for 2 to 10 years the values of total porosity
are higher for Ismailya than for ~ubariya soils
particularly in deeper layers. Generally in both
t
soils total porosity tend to be higher in the sur.race
layers than in the deeper ones. The total porosity
seems to have increase upon cultivation. Void ratio
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87
behaves in a similar way as total porosity. It
seems to have increased upon cultivation.
Pore Size Distribution:
In . general the water-holding pores (W. H.P)
predomina~te the other types, while the fine capillary
pores (Foe.p) represent the lowest portion. Quickly
drainable pores (Q.DoP) and slowly drainable pores
(S.D.P) followed the water holding pores (W.H~_.
Q.D.P tends seems to have decreased on cultivation
to reach their lowest in soils cultivated for 10
years. .In contrast, the other types of pores (i. e 0
slowly· 7 drainable, water holding and fine capillary
pores } seem to have increased on cultivation. This
was more pronounced in soils at their earlier rather
than latter stages of cultivation. The quickly
drainable pores (QoD.P) tend to increased with
depth. The comparison between pore size distribution
of Nubariya and Ismailya soils show that the soils
at Ismailya region are characterized by higher
values of WoH.P and lower values of S.D.P as compared
to those at Nubariya region. The difference are
more detectable in soils urJder cultivation for
2 to 10 years.
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Hydraulic conductivity:
Hydraulic conductivity values of Nubariya
soils are very low in the virgin soil and the soil
for
cultivated / one year. They are sharply greater in
soils cultivated for 2 to 10 years. Hydraulic conductivity
seems to have been affected by cultivation
as well as soil depth. with increasing of cultivation
period. the hydraulic conductivity seems to have
decreased.
This holds true for both surface and
subsurface
in soils of more further years of cultivation and
layers. Changes are more detectable
at deeper’ rather than surface layers. The hydraulic
conductivity of the soils at Ismailya region exhibits
a similar pattern of changes as thos at Nubariya.
Comparing Nubariya and Ismailya soils the hydraulic
conductivity tends to be higher in the latter.
especially in virgin soils and those under cultivation
for 2-3 years.
Soil Moisture Constants:
The soil moisture constants at Nubariya region
seems to have been mainly affected by soil texture
J which must have been changef on cultivation. Where
the soil texture tend to be finer, the soil moisture
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constants exhibit higher values. The values of
field capacity of Nubariya soil are in the range
of 31.29 to 41.85% in virgin and one year cultivated
soils and 16.58 to 29.46% in soils cultivated for
2 to 10 years.
Similar trends are achieved for the other
two moisture constants, i.e. wilting point and
available water. However r values tend to be higher
in soils cultivated for shorter period~ especially
at surface layers. The effedt of cultivation on
moisture constants is more .pronounced on field
capacity rather than on wilt~ng point. The result
is an increase in available moisture. The effects
of soil depth on moisture constants are more pronounced
in cultivated soils especially those under shorter
periods of cultivation.
Regardless the soil texture, the
constants of Nubariya soil seem to have
on cultivation. At Ismailya region the
of soil moisture constants are similar
at Nubariya region.
moisture
increased
patterns
to those