الفهرس 
Material and methodsOnly 14 pages are availabe for public view
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Abstract
5. Summary and Conclusion
This work was carried out to investigate the effect of the
quality and quantity of irrigation waters on some chemical
properties of three soils of Egypt as well as on dry matter yield
and chemi ca 1 components of sorghum p1ant grown on these soi 1s.
Such a study which involved the interaction between irrigation
water soil and plant might provide important measures in assessing
the suitability of different waters for irrigating different
soils.
To fulfill the purposes of this study, soil samples were
taken from three different locations (Moshtohor, Meet-kenana and
Ameriah). These soils varied widely in their physical and chemical
properties and were used in conducting the pot experiment.
The pots were divided into two groups, the first one was perforated
from the bottom to allow drainage and the second contained
inperforated pots. The studied soil samples were packed
uniformly in the pots and planted with sorghum as an indicator
plant. The irrigation treatments involved three salt concentrations
in the used waters , namely, 500, 2000 and 5000 ppm. and
each concentration contained three SAR values, namely, 1, 10 and
20. Irrigation waters were appl ied to the soi ls in quantities
corresponding to their field capacities in the inperforated pots
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and 1.3 fold of field capacities in the perforated ones. Dai ly
applications of irrigation waters were carried out to replenish
the water depletion occurred due to evapotranspi ration and
drainage.
At the end of experiment which extended 60 days, sorghum
plants were harvested, oven dried, digested and analyzed to
determine their contents of Ca++, Mg++, Na+, k+, Nand P. Also,
the upper (0-15cm) and lower (15-30 cm) soil layers in each pot
were air dried, crushed, sieved through a 2 mm sieve and chemically
analyzed to determine EC, soluble cations and anions and
exchangeable cations. The obtained results can be summarized in
the following:
1 - Increasing salt concentration in the used water increased
the electrical conductivity of the studied soils, regard-
1ess to the ir SAR va 1ues .Th is increase was rna re pronounced in
the soils packed in the inperforated pots due to salt accumulation
in thesesoi 1s owing to the absence of leaching. The SAR
value of irrigation waters showed contradictory effects on soils
salinity. However, the upper soil layers tended, generally, to
maintain a relatively higher amount of soluble salts than the
lower one due to evaporation.
2- Taking into consideration the initial concentration of the
soluble cations and anions in the investigated soils, it can be
noticed that:
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a) Increasing salt concentration of the applied water to the
soils packed in the inperforated pots increased their contents of
so 1ub 1e Na+, K+, Ca++ and Mg++. Also, increas ing the SAR values
was associated with an increase in soluble Na+ and a corresponding
decrease in Ca++ content.
On the other hand,increasing the Quantity of water applied
to the soils packed in the perforated pots although caused a
relatively lower increase in soils contents of Na+ and Ca++ I the
K+ and Mg ions either, slightly increased or reduced according to
the soil type, salt concentration and SAR values of the appl ied
water.
b) The studied saline waters did not affect the soils content
of soluble CO--s which remained almost, the same, while HC03
ions increased in the sandy and clay soils with increasing salt
concentration in the applied water above 500 ppm. The increase in
soluble HCOs- seemed to be associated with the increase in SAR
values of irrigation water.
c) Increasing the Quantity of ~pplied water, regardless to
its salt concentration or SAR value, reduced the soil content of
504 - - •
d) Exchangeable Na, generally, increased in the upper layers
of the studied soi ls, and this increase was more pronounced by
increasing salt concentration in the applied water. Also clay
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soil contained the highest exchangeable Na+. Increasing the SAR
value of irrigation water was associated always by increasing the
soils content of exchangeable Na+.
e) Increas ing both salt concentration and SAR value of the
applied waters decreased the exchangeable Ca++ content of the investigated
soils. However, the content of exchangeable CaH in
the upper layer of ca1ceareaus soil increased.
f) However, soil contents of Mg++ were high in the calcareous
soils, the lowest Mg++ content was obtained in the sandy
soil. In most cases, soil content of exchangeable Mg++ tended to
decrease with increasing the SAR va1ue.of irrigation water.
g) Increasing the applied quantity of irrigation water up to
1.3 soil field capacity, decreased to a great extent, exchangeable
K+ content in the sandy soi 1. Also, neither the salt concentration
nor the quantity of irrigation water appear an effect
on exchangeable K+ content in the calcareous soil.
3 - Dry matter yield of sorghum plants grown on clay soil was the
highest and followed by that of calcareous soil and finally that
of sandy soil. It was found also that, increasing salt concentration
in the applied water reduced the dry matter yield in
all the investigated soils. While SAR values of irrigation water
appeared no effect on dry matter yield.
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4- Plants grown on sandy soil and irrigated up to either field
capacity or 1.3 field capacity did not continue and died after 4
weeks upon utilization of the highest saline irrigation water.
5- Chemical constituents of the sorghum plants grown on the clay
soil can be summarized as follows:
Increasing salt concentration in the applied water increased
the plant content of Na+ ions. Irrigation by waters of SAR equals
10 and increasing salt concentration from 2000 up to 5000 ppm increased
Na+ content in the plant by three tines.
Plant content of Na+ seemed to be related to the status of
Na+ in the soil solution which was increased with increasing the
salt concentration and BAR value of the applied water.
Plants content of K+ decreased by increasing salt concentration,
however, SAR value and quantity of irrigation water had no
effect in this regard. Therefore, the dominant factor which affected
appreciably the plant content of K+ was the salt concentration
of the applied water.
Calcium content in the plants irrigated either up to field
capacity or 1.3 field capacity increased by increasing salt concentration
in the applied water. However, increasing the SAR
value reduced the plants content of Ca++.
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Magnesium content in the plants irrigated up to field
capacity tended to decrease with increasing salt concentration of
the irrigation water. However, there was no effect due toSAR
value of the water.
The plant content of N was lower at the treatment irrigated
up to field capacity than that of 1.3 fold of the field capacity.
While, plant content of P was not affected by salt concentration,
SAR value or quantity of the applied water.
6 - The results of chemical constituents of the plants grown on
the sandy soil, can be summarized as follows.
Plant contents of both Na+ and Ca++ ions increased with increasing
salt concentration of the irrigation water. However,
upon irrigation with any salt concentration of the applied water,
plants content of Na+ increased by increasing the SAR values of
irrigation water. but that of Ca++ decreased. Also, plant contents
of Na and Ca were higher upon irrigating the plants up to
field capacity as compared with the other irrigation treatment
(1.3 field capacity).
Plant content of K+ decreased by increasing the salt concentration
in irrigation water. On the other hand, plants content
of Mg varied according to salt concentrations in the applied
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--_ .._ ...._----~-----------------------------------
water, as well as its quantity, however, no trend was observed
due to the variation in SAR values of the water. Also, Mg content
in the plants irrigated up to field capacity was higher than that
in the plants irrigated up to 1.3 field capacity.
Plants content of nitrogen decreased by increasing salt
concentration in irrigation water and upon irrigation up to field
capacity. However, an apposite trend was observed in the soil
irrigated up to 1.3 of its field capacity. On the other hand,
the plant content of N was increased by increasing the salinity
of applied water. In this regard, SAR values of the applied water
seemed to exert no effect on plants content of N.
Phosphorus content in plants grown on soil irrigated up to
1.3 fold of its field capacity increased with increasing the
salt concentration of the applied. water from 500 to 2000 ppm, but
it decreased sharply when the salt concentration raised up to
5000 ppm.
7-· Concerning the chemical constituents of the plants grown on
calcareous soi 1, the obtained results show that increasing the
salt concentration of the water whether that applied in quantities
equivalent to the soil field capacity or 1.3 fold of its
field capacity increased the plants contents of Na+ and Ca++
ions. However, at any of the used salt concentrations, increasing
the BAR value increased plants content of Na+ and decreased Ca++
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content. The plant contents of Na+ and Ca++ upon uti 1ization of
quantities of water equivalent to 1.3 field capacity, were relatively
lower as compared with the former irrigation treatment.
Plant content of K+ upon irrigating the soil up to filed
capacity, tended to decrease with increasing salt concentration
of the applied water, while, SAR value seemed to have no certain
effect. Also increasing the quantity of irrig:ation water up to
1.3 field capacity ,increased the plants content of K+.
The plants content of Mg was high upon irrigating the soil
with the highest salt concentration of water (5000 ppm) and low
upon the use of the lower salt concentration of water (2000
ppm) •
On the other hand, N content in the plants grown on the inperforated
pots was relatively lower than that grown on the perforated
ones. Increasing the salt concentration of the appl ied
water increased the plant content of N upon irrigating the soil
up to 1.3 fold the field capacity. While, there was no effect
due to various SAR values or concentration of the app1 ied water
upon irrigation with a quantity of water equivalent to soil field
capacity.
The highest plants content of P was found upon utili zat ion
of the intermediate salt concentration of the applied water (2000
ppm). However, there was no influence of SAR values on the
plants content of P.