الفهرس 
Material and methodsOnly 14 pages are availabe for public view
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Abstract
SUMMARY
The purpose of this investigation was to study the effect of
pollution on the soil of Abu Rawash farms due to continuous
irrigation with sewage water.
Change in some physical and chemical properties were
recorded and evaluated. Fifteen soil profiles were selected to
represent four locations irrigated with sewage water for
different periods. namely 2. 4, 8 and 10 years. and one location
to represent control soil (unirrigated with sewage water). Soil
samples representing the subsequent layers of the investigated
profiles were analysed for evaluating properties of the studied
soils. Results obtained could be summarized as follows;
***
The colour of surface layers changed from very pale brown to
very dark gray brown in dry soil, and changed from yello
ish
brown to very dark brown in moist with increasing period of
irrigation, w~ereas that of subsurface layers changed slightl~
_** Irrigation of soil nth. sewage water for a period less than two
years di.dnot markedly affect soil texture. However. continuous
irrigation wi.th sewage water was associated wi. th a sli.ght change
.I in. texture 0 f the surface layer from sandy to loamy sand and change
extended to the deeper layers up to 30 em depth with time.
On the other hand, no changes in texturel classes occurred in layerf
deeper than 30 em.
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*** Soil organic matter content significantly increased.due to
the irrigation with sewage water. Accumulation ·oforganic
matter was more pronounced in the surface soil layers
compared to the sUbsurface ones.
*** Calcium carbonate content was slightly influenced by
continuous irrigation with sewage water.
***
Soi~ Bulk. density values decreased with increasin.g period 0 f
irrigation. and lower layers were generally of ~gher values than
the surface ones.
Maximum Water Capacity increased with increasing period of
irrigation with sewage water. and values of maximum water
capacity of the surface layer of soils were higher than those of
the subsurface ones.
*** Permeability decreased by using sewage water for irrigation
due to the presence of suspended materials.
*** Soil PH decreased by using sewage water for irrigation’
GenerallY,surface layers with higher content of organic
matter persisted to shoW lower values of pH than the
subsurface layers.
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*** Applying sewage water up to 8 years led to a decrease in soil
salinity due to washing out most of salts from the virgin
sandy soi Is~fter that, there was a gradual increase\ in soi 1
sal inity v~w1th the length of the period of sewage water~wage
.utilization. tion .
•*. As a result of leaching out salts upon. applying sewage water for.
period of two years, a sharp decrease accurred in soil content of
soluble Ca++, Mg++,Na +and K+• However, Ca++ and ria+ were the
uominant cations in the solution followed by Mg++and K+ •
*** The HC03 tended to I increase with the length of applying
sewage water. After 8 years of sewage water utilization
504 followed the same trend of HC03. Also. Cl content
decreased as period of irrigation increased. 504 was the
dominant anion in the soil solution followed by HC03 and Cl.
** Irrigation with sewage water was associated with increase in
the cation exchange capacity and exchangeable Ca.Mg.Na and K
especially in the surface layers.
Exchangeable Ca and Mg dominated the exchangeable cations
due to the higher affinity of the investigated soils for Ca
and Mg than Na and K.
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*** Utilizing sewage water for a periud of 10 tears led to an. increase
in total and soluble H and total and available P.
The.accumulation. of these two nutrients was usually confined to
the top and sharply decreased with depth.
*** There was a gradual increase in soil content of total and
available K by prolonged period of irrigation with sewage
water.
*** There was a significantly increase in soil content of total
and available N. P and K with soil organic matter.
*** Generally. soil content of micronutrient elements (Fe. Mn, Zn
and eu) increased with prolonging time of irrigation with
sewage water and the accumulation tented to take place
mostly in top layers.
*** There was a significantly positive correlated between soil
content of total and available micronutrient (Fe.Mn, Zn, eu)
and soil organic mater and silt+clay contents. Also, There
were significantly negative correlated between
micronutrients and soil pH.
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***
***
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Generally. the heavy metal content (Pb. Cd.Co.Cr.and Ni)
increased with prolonging periods of irrigation with sewage
waters. and the accumulation of heavy metal content was more
pronounced in the surface soil layers compared to in the
subsurface ones.
There were a significantly positive correlated between total
Fe.Ni.Co,Cd and Cr contents and organic matter contents and
silt+clay contents, except total Cd content with
silt+clay.Also, there were a significantly negative
correlated between previous heavy metal and soil pH.
*** There were a significantly positive correlated between
available Fe, Ni.Co.Cd and Cr contents and organic matter
contents and silt+clay contents. Also. there were a
significantly negative correlated between previous available
heavy metals and soil pH.
*** There were a significantly positive correlated between
previous total heavy metals contents and available
ones.
forms
*** Generally. the prolonged period of irrigation with sewage
waters has markedly increased the amount of trace elements
in plant. but the trace element levels in the leaves and
juice fruit citrus and field crops (Faba-bean.Lupin) are
below the standard level values.
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