A green house pot experiment was conducted on a newly
reclaimed clay loam calcareous soil at the eastern edge of Tamia
district, El Fayoum Governorate. It was cultivated with barley
(Hordeum vulgare, Giza 123) and irrigated with water of different
salinity levels, i.e., 750, 1500, 3000 and 4500 mg/L, prepared from
NaCl, Na2CO3 and Na2SO4 salts. The current study aimed at
identifying the response of both soil and grown barley characteristics
to the total salt concentration as well as specific anion effects.
The obtained results showed pronounced increases in the values of
bulk density and soil strength vs decreases in soil total porosity,
hydraulic conductivity and available water range with increasing
irrigation water salinity levels. Also, the negative effect depends upon
salinity level and specific anion, however, both NaCl and Na2SO4 salts
exhibited slightly hazardous effect vs an extremely one for Na2CO3,
may be due the formation of false soil aggregates in the first case and
the destroyer effect in the later one. The hazardous effect of the
accompanied anions was arranged as follows: CO32- > Cl- > SO42-. In
general, increasing applied water salinity levels resulted also in an
increase for each of soil pH and ESP vs decreases in the released
available nutrients for grown plants.
Results indicated that the hazardous effect of applied NaCO3
solution was extended to the grown barley characteristics. Barley
vegetative growth parameters (plant height, No. of tillers/plant, No. of
leaves/plant, leaf area/plant and leaves dry weight/plant) showed
gradual decreases with increasing water salinity levels. Also, it is
evident that the relatively high soil salinity leads to an uptake
inhibition of plant roots for all nutrients, due to the inability of
subcellular osmotic units to adjust the relatively high osmotic pressure
and ionic strength.
Similar trends were noticed for barley yield (straw and grains)
and its components (No. of grains/spike, 1000 grain weight, protein
content % and nutrients uptake by plant). It is noteworthy to mention
that reductions in yield resulted from the decreases in the number of
grains per spike rather than the decrease in 1000 grain weight, which
seems to be almost stable against the change of the unfavourable
conditions of irrigation water salinity levels. Also, the reductions in
straw yield, which amounted about 24-39 % at the highest water
salinity level, were a function of the decrease in plant height in a
minor magnitude due to tillering capacity of relatively major
magnitude.