556
2.4 Jordan
A field experiment on supplemental irrigation was conducted by ICARDA and the
National Center for Agricultural Research and Extension (NCARE) at Marrou
Agricultural Station during the 2013–2014 and 2014–2015 growing seasons. Two
durum wheat cultivars, ACSAD (V1) and Cham-1 (V2), and one bread wheat culti-
var, Ammon (V3), were used as plant material. Each cultivar was subjected to four
water (supplemental irrigation) levels: (I) 100 % FC, (II) 75 % FC, (III) 50 % FC,
and (IV) rainfed control (R). The area of each subplot was 20 m^2 with 21 rows, with
25 cm line spacing. Hand planting was done on December 23, 2013, and November
30, 2014, at a rate of 200 seeds per line. The whole experiment was fertilized with
DAP at a rate of 10 g m−^2.
Irrigation was applied using a drip irrigation system. Water amounts needed to
apply the specified water level was based on the soil water content at 0–60 cm mea-
sured by the gravimetric method using a time domain reflectometry (TDR)
instrument.
The first growing season (2013–2014) was relatively dry with total growing-
season rainfall of 321.5 mm compared to a long-term average of 400 mm. The sec-
ond growing season was wetter-than-normal with total growing-season rainfall of
539.4 mm. Accordingly, the need for supplemental irrigation differed between the
two years with more water applied in the first year compared to the second.
During the first growing season, irrigation treatment I (100 % FC), cultivar
Ammon (V3) produced the highest biological and grain yield followed closely by
Cham 1 (V2) for the same irrigation treatment. For the wetter-than-normal second
growing season, irrigation treatment II (75 % FC), cultivar Cham 1 (V2) produced
the highest biological and grain yield. For first growing season (2013–2014), crop
yield increased by as much as 92 % by switching from rainfed to full supplemental
irrigation, and for second growing season (2014–2015), by as much as 21 % using
irrigation treatment II. The highest water productivity, with regard to rainfall +
water applied, was achieved for full SI during the dry year and for rainfed in the wet
year.
Supplemental irrigation is typically not effective in a wet year when the crop
meets most of its water requirement from rain, which was evident here. Regarding
statistical analysis (Table 4 ), there was a significant difference between irrigation
treatments and cultivars for biological and grain yield with years.
Overall, the study confirmed that the application of supplemental irrigation sig-
nificantly increased crop yield in a dry year, and that water productivity signifi-
cantly increased with water application during critical growth stages.
2.5 Algeria
Algeria is among the most water-scarce countries in the WANA region. Herda et al.
( 2015 ) conducted a study, under the ICARDA Water Benchmarks Project, to assess
the response of five durum and five bread wheat cultivars to deficit supplemental
V. Nangia and T. Oweis