Rice (Oryza sativa. L) is considered one of the most important food crops,
as it is a more profitable one than the other summer crops from the economical
point of view in Egypt. Also, it is not only stable food source for majority of the
Egyptian population but also it has become one of the most exportable crops in
Egyptian agricultural system after the free cropping pattern policy. For these
reasons, the areas cultivated with rice have been annually increased, although it is
one of the most inefficient in water use among field crops due to it grows
generally under continuously submerged conditions. Under the key of saving
water conditions and achieving high water use efficiency, a special attention was
focused to optimize transplanting method and irrigation water management for
raising the water use efficiency of rice plants through a proper their equitably
distribution among all rice fields. Thus, the problem is how to distribute the
irrigation water equitably among all rice fields with high water use efficiency?.
To achieve a profitable solution for this problem, a field experiment was
conducted on a sandy clay loam soil during two successive growing summer
seasons 2007 and 2008 at a private farm, Sinnuris district, Fayoum governorate,
Egypt to evaluate the effect of applying a new method (M) for rice transplanting
(transplanting on strips) on rice yield and its components as well as some soilwater relationships. However, rice seedlings of two rice cultivars of Hybrid 2 and
Sakha 104 were transplanting at furrow bottoms of either 60 cm (M2) or 80 cm
(M3) apart as compared with the traditional transplanting method (M1,
transplanting on a flat soil), under different submerged irrigation water depths of
6 cm (D1) and 8 cm (D2).
The obtained data indicate that highly significant differences were existed
among the studied transplanting methods, among some plant parameters of
growth (i.e., plant height) and rice yield (i.e., panicle length, 1000 grain weight,
grain and straw yields). These differences are confirmed by the mean values in
combined analysis for the plant heights which recorded 100.30, 105.18 and
107.12 cm for M1, M2 and M3 treatments, respectively. Also, the tallest rice
plants were significantly affected by both rice cultivars and submerged irrigation
water depths, where plant height was recorded 107.1 cm at a depth of 8 cm (D2)
for Hybrid 2 cultivar as compared with Sakha 104 which was 101.3 cm as an
average of the two growing seasons.
Results showed also a significantly increase in panicle length due applying
the new transplanting method, where its mean value in combined analysis were
19.56, 20.93 and 21.71 cm for M1, M2 and M3, with a superiority for D2 (8 cm
depth) and Hybrid 2 cultivar as compared with D1 (6 cm) and Sakha 104,
respectively. Also, the corresponding mean values were 26.13, 28.71 and 29.25
gm for 1000 grain weight of rice vs 26.53 and 29.53 gm for submerged irrigation
water depths of D1 (6 cm) and D2 (8 cm), respectively.
As for the rice grain yield as affected by rice cultivars, transplanting
methods, submerged irrigation water depths and, the obtained data reveal that the
mean values in the combined analysis were 5.269 and 4.197 ton fed-1 for Hybrid 2
and Sakha 104, with the relative increase percentages due to applied M2 and M3
treatments of 9.78 and 13.70 % over the control treatment (M1), respectively. The
corresponding mean values of grain yield were 4.517 and 4.949 ton fed-1 for D1
and D2, respectively. A similar trend was obtained for straw yield, as it is
significantly increased in case of Hybrid 2 cultivar, transplanting on strips and D2
(submerged irrigation water depth at 8 cm) in individual and combined seasons.
Data of over both seasons indicate that applied both M2 and M3 treatments
resulted in saving water amounts reached 1890 (30.15 %) and 2136 m3 fed-1
(34.06 %) as compared with M1 treatment, respectively. Data showed also that
irrigation water depth was a highly effect on saving water, where the greatest
value of water saved (2263 m3 fed-1 ā 35.97 % as an average of two growing
seasons) was found under irrigation water depth of 6 cm (D1). Regarding the
impact of rice cultivars, Hybrid 2 recorded a greatest value of saving water (2365
m
3
fed-1 ā 36.64 % as an average of two growing seasons) as compared to Sakha
104, which recorded saving water value of 2161 m3fed ā 33.54% as average of
two growing seasons. Thus, it is recommended by applying the transplanting of
rice seedlings (Hybrid 2 cv.) on strips at 80 cm apart, with a submerged irrigation
water depth of 8 cm to maximize both grain and straw yields vs saving irrigation
water and increasing unit productivity of either soil or water from rice yield.