الفهرس 
Experimental ProceduresOnly 14 pages are availabe for public view
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Abstract
Two pot experiments were carried out under greenhouse conditions of the National Research
Center (N.R.C.) to study the effect of heavy application of phosphate fertilizers and intervals
of their addition on the growth along with phosphorus, cadmium and fluorine contents of both
peanut (as a summer crop) and bean (as a winter crop) plants grown on different soils.
Soil analyses showed a wide variation in the figures of either total or available phosphorus
extracted from different studied soils; the highest values were encountered with both clay and
loamy samples with calcareous and sandy ones being lowest. Contents of both total and available
phosphorus in all studied soils were positively correlated with both silt and clay soil fractions
but negatively correlated with CaC03 content,
longer period favorable for or sandy soils.
of superphosphate application being both indicated forms in either calcareous
Almost similar trend was obtained for responses of
·both cadmium and fluorine to either rate or duration of superphosphate application.
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Obtained results showed that regardless to soil type. increasing the rate of applied
P-fertilizer or duration of fertilization resulted in a corresponding increase in dry matter
content of the studied peanut plants. Values were higher with clay soil samples compared to
either sandy or loamy ones. calcareous soil samples being inferior. This is true in spite of
relatively less
responses
to relatively heavy
fertilization or relatively longer periods of fertilizer application possibly due to interaction
between available phosphate and other ions present in soil.
Results also showed that increasing the rate of applied P-fertilizer gave a corresponding
increase in the dry matter content of faba bean plants: loamy soil was
relatively
to sandy or clay ones.
with
calcareous soil samples being inferior. This is true in spite of relatively lower responses of
plants to the high applied rate. again possibly due to interaction of available phosphate with
other ions present in the concerned soil. Significant responses for faba bean plants to duration of
superphosphate application were also obtained. responses being more pronounced in calcareous
soil than in sandy one.
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Phosphorus status in plants of both showed similar. positive responses
studied crops to · phosphate
fertilization; such response was again more pronounced as
the rate of applied phosphate ferti1izer W<1S higher ·with calcareous soil being least affected
and sandy one most responded. Obtained positive response of P status was suggested to be due to
relatively higher levels of available P present in soil, variations of studied soils being
explained on the basis of relatively high P fixation capacity of calcareous soils when compared
with sandy ones.
Status of cadmium in the studied plants followed a trend similar to that of phosphorus. It showed
clear
differences
among the different
studied
soils with
positive responses
to either
rate of
applied
superphosphate or
duration of its fertilization, sandy
soils being less responded if compared to calcareous ones.
Again, status of fluorine in the plants of both concerned crops showed clear differences among
the different studied soils with positive responses to either applied superphosphate or duration of
its fertilization, calcareous soils being less responded if compared to
sandy ones.