The main objective of this work was to investigate the impact of using two
irrigation systems, i.e., modified surface irrigation with cement gated passers
(flooding) and sprinkler irrigation on the pattern distributions of soil moisture
and salts as related to plant characteristics and grain yield of wheat (Triticum
aestivum L., Sakha 93 cv.) grown on a desert sandy skeletal soil at Inshas area
that was reclaimed and cultivated since 1959 A.D.
The obtained results showed that irrigation water was classified as C1S1,
i.e., ECiw value = 0.35 dS/m or 0.75 dS/m and SAR 1.42 or < 6, indicate that the
used irrigation water have no soil salinity or sodicity problems are expected.
Also, the studied soil is characterized by a relatively coarse texture grade. i.e.,
sandy loam that characterized by low capacity to retain either soil moisture or
nutrients to the grown plants. By using a parametric evaluation system for
irrigated agriculture land, it was found that soil texture represents a limiting
factor for its productivity as well as the studied soil belongs to a moderately
suitable class (S2) in both current and potential conditions. Meanwhile, it could
be evaluated as marginally (S3) and moderately (S2) suitable adaptations for
winter wheat at the current and potential conditions, respectively.
It was also showed that the actual consumed value of irrigation water
required for the grown wheat plants under the prevailing conditions of the
experimental soil was 1775.5 m3 fed-1 vs 2683.0 under modified surface
irrigation and 2104.7 m3 fed-1 under sprinkler systems, with water saving of
about 21.55 % in irrigation water for the later one. That was true, since such
saving of water is more attributed with the water efficiency use values that were
66.18 and 78.47 % for modified surface irrigation and sprinkler, respectively.
Moreover, the data indicated that the soil salinity levels were liable to
seasonally change with different efficiencies of salts removed reached about 22-
25 vs 16-19 % throughout soil profile layers under the modified surface and
sprinkler irrigation systems, respectively. Practically, soil moisture contents
reached almost values of wilting point at the eleventh and fifth days after
irrigation under the applied irrigation systems of modified surface irrigation and
sprinkler, respectively. Consequently, the corresponding best irrigation intervals
were 11 and 5 days under the prevailing environmental conditions of the current
experiment, respectively.
Wheat vegetative growth parameters, i.e., plants intensity in m2, plant
height, No. of tillers/plant and dry weight/plant as well as harvest parameters,
i.e., spike length and No. of grains/spike, grain and straw yields were affected
by both applied irrigation systems, with successfully parameters for plants
irrigated with sprinkler system. This was more attributed with the uniformity of
soil-water distribution a certain stage of germination and seed response, may be
due to easily irrigation water flow among whole field with high efficiency use in
short time with low losses either by down movement under such relatively
coarse textured soil or evaporation under hot-arid climate.