الفهرس 
Material and methodsOnly 14 pages are availabe for public view
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Abstract
The current investigation was carried out to study
the effect of organic m a n u re , mineral f e r t i l t z e r s and
artificial feed on both different soil properties and
fish production. Moreovert the effect of different
stoc ing rates on the fish production was also studied.
(A) To achieve the first p u rp o se , five ponds in
El-$ row Fish Farmt Dakahlia Governoratet were chosen to
carr out the following treatments:
1. T e first pond was fertilized with organic manure
a ly.
2. T~e second pond was fertilized with two mineral fertilizers
i.e ammonium sulphate and superphosphate.
3. T~e third pond was fertil i ze d with organic manure
t~gether with mineral fertilizers.
4. A~tificial feed was used in the 4th pond alone.
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5. T~e fi vth pond wa s control t i. e no fert i 1 izers or
artificial feeds were used.
All these ponds were stocked with Tilapia s pp .,
Cyprinus carpio and Mugil cephalus at the rate of 1800
fish per feddan for a growth period of 160 days.
To study the effect of di fferent treatments on
somej soil physical and chemical properties, soil samples
we reii t a ken fro m 0 - 10 , LO- 2 5 and 2 5 - 6 0 c m s 0 i 1 d e p t h 5
at: lt he beginning of the study, after three months and
i
a t tl h e end 0 f stu dy, i .e aft e r h a r v est i ng the f ish and
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dryilng ponds of the farm.
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Al so, water samples were taken monthly for anal
y s ns from the five ponds and from the source and drainage
water. In the same time, random samples from all
reared fish species were taken and weighted every month
from June 1989 to November 1989.
The obtained results can be summarized as follows:
(I) The effect of di fferent treatments on some
soil physical properties:
1. Particle size distribution was not affected by the
used treatments.
2. The values of soil bulk density were decreased in all
fertilized ponds, except in the pond recieved mineral
fertilizers. So i 1 bulk dens i ty increased wi th
increasing soil depth. The values of soil bulk density
were significantly and negatively correlated
with OM%, AS% and EMgP. While they significantly and
positively correlated with both of Sol-Na ESP.
Moreover, the addition of organic manure with or
wi thout mineral fertil izers significantly increased
total soil porosity.
3. No clear trend was observed, concerning the effect of
different treatments on the values of soil hydrau’iiC
conductivity (K). They decreased on most ponds and
increased in few ones.
4. The values of DSA% of 4.8-2.5 mm in diameter were
increased by the addition of organic manure with or
without mineral fertilizers. While, both mineral fertiz1iers
and artificial feed did not significantly
affected DSA%. On the other hand, a significant and
negative correlations were found between DSA% and
both of AU and ESP, while the opposite was true for
5. WSA% of 1.6-0.8 mm and 0.8-0.4 mm in diameter were
increased by manuring in the surface soil layer,
also the WSA% of 0.8-0.4 mm and 0.4-0.2 mm in
diameter were increased in the deepest one. It was
also found that, the addition of organic manure plus
mineral fertilizers raised the values of WSA% of
0.8-0.4 mm and 0.4-0.2 mm in diameter in the surface
and subsurfae soil layers.The opposite trend was
found in the case of mineral fertilizers and
artificial feed where, their additions lowered the
WSA% of 0.8-0.4 and 0.4-0.2 mm in diameter in all
soil depths. The values of WSA% were significantly
and positively correlated with OM%, EMgP and ECaP.
While, they significantly and negatively correlated
with rc, Bd and ESP.
3. Soluble cations and anions:
a) Soluble Na was decreased in most experimental
ponds especially in the surface layer and in the
presence of organic manure. The concentration of
Sol-Na at the end of the study was between one to
four fivth of the original levels.
b) Soluble-K followed nearly the same trend of Sol-Na.
c) The changes of Sol-Ca were unlimited, and there was
no clear trend concerning the effect of different
treatments at the end of study.
d) Soluble-Mg was decreased by about 10% to 68.64% at
the end of study and as a result of different
treatments.
e) Soluble-Cl was decreased rapidly in the ponds
initially contained high concentration of Cl-,
f) There was no measurable amounts of C03,
The values of HC03 were decreased in the fertil ized
ponds~ while~ they increased in the pond treated with
artificial feed in the surface layer. The opposite was true
for the deep layers.
g) Soluble-S04 decreased in all experimental ponds in all
all soil depths.
4. OM% was considerably increased in most ponds, The
percentages of increase were 10.31% and 12.22 in the
ponds fertilized with organic manure only or organic
manure plus mineral fertilizers, respectively. OM%
was significantly and positively correlated with AS%,
while it negatively correlated with soil pH.
5. The values of soil CEC increased in most investigated
ponds, but this increase was not significant. As
a general trend, soil CEC increased with increasing
soil depth.
6. Soil ESP slightly increased (0.42-15.69%) at the end
of study in the pond fertilized with organic manure,
while, it decreased by about 4.99 and 50.19% in the
other ponds.
Similar trend was also noticed for EKP.
7. The values of both ECaP and EMgP were increased in
most investigated ponds at the end of experiment. The
observed increases of both ECaP and EMg P were correlated
with the increases of soluble calcium and magnesium
in the pond1s water.
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( I I I ) Effee t a f d iff ere n t t rea t men t son f ish
production:
Results of the first experiment showed that:
1. The growth rates of different fish species reared in
the pond fed wi t h art i f i cia 1 feed were higher than
that reared in the fertilized ponds.
2. The addition of organic manure to the fish pond gave
best production of Mugil cephalus as compared with
mineral fertilizers which were not useful.
3. Total fish production of fish reared in the pond fertilized
with organic manure plus mineral fertilizers
was less than that of the pond treated with artificial
feed. But it was higher than the production of
the ponds fertilized with either organic manure or
mineral fertilizers alone.
4. Statistical analysis showed that, there was no significant
difference between the fish production in
the pond fertil ized with organic manure alone and
that fertilized with organic manure together with
mineral fertilizers. The lowest production was
obtained in the pond fertilized with mineral
fertilizers alone.
So it can be said that, the addition of mineral
fertilizers to the fish farms is not important. While,
it can be recommended the use of organic manure - with
care _ in the fish farms instead of the artificial feed
to reduce the cost of production.
(B) In order to realize the second purpose of the
study, i.e. the effect of different stocking rates on
fish production. three ponds were chosen. These ponds
were stocked with Tilapia spp .• Cyprinus carpio and
Mugil cephal us in polyculture system with three
different stocking rates i.e, 2100, 3150 and 4200 fish/
feddan. The ratios between the three fish species were
75 : 18.3 and 6.7% for Tilapia Cyprinus carpio and M.
cephal us, respectively.
The reared f is hes were fed wi th a mi xture of
organic manure, mineral fertilizers and artificial
feed. The experiment lasted 160 days.
The obtained results can be summarized as follows:
1. Growth rates of Tilapia spp. decreased with increasing
the stocking rate, while the total production
was increased.
Statistical analysis showed that, although the
final weight of tilapias in the lowest stocking rate
was higher than the other two rates, the difference
between their final weightrwere not significant.
it can be recommended the use of organic manure _ with
care - in the fish farms instead of the artificial feed
to reduce the cost of production.
(B) In order to realize the second purpose of the
study, t . e . the effect of different stocking rates on
fish p r o duc t t nn , three ponds were chosen. These ponds
were stocked with Tilapia spp., Cyprinus carpio and
Mug;l cephalus in polycu1ture system with three
different stocking rates i.e, 2100, 3150 and 4200 fish/
feddan. The ratios between the three fish species were
75: 18.3 and 6.7% for Tilapia Cyprinus carpio and M.
cephal us, respectively.
The reared fi shes were fed wi th a mi xture of
organic manure, mineral fertilizers and artificial
feed. The experiment lasted 160 days.
The obtained results can be summarized as follows:
1. Growth rates of Tilapia ~ decreased with increasing
the stocking rate, while the total production
was increased.
Statistical analysis showed that, although the
final weight of ti1apias in the lowest stocking rate
was higher than the other two rates, the difference
between their final weightt!were not significant.