ICARDA annual report 2004

ments by nearly 25%, so extension
efforts are needed to promote efficient
water use. The FWUE of two
irrigated forage crops, berseem and
corn, was also high in Egypt
(0.72–0.76 kg/m 3; Fig. 28), and
greater than that of faba bean (0.55
kg/m 3) and sunflower (0.64 kg/m 3).
The FWUEs of vegetable crops
varied among locations and crops.
For example, tomato’s FWUE
ranged from 0.53 to 0.69 kg/m 3
across four different sites (Fig. 29).
The FWUE of watermelon and pepper
also varied between locations,
being much higher in Nubaria,
Egypt (0.76 kg/m 3 and 0.74 kg/m 3,
respectively) than in Al Ghor, Jordan
(0.44 kg/m 3 and 0.53 kg/m 3, respectively).
Differences between crops
were also found within a location:
the FWUE of eggplant (0.66 kg/m 3)
was considerably higher than that of
cucumber (0.56 kg/m 3) in Al Ghor,
illustrating that water is not used
efficiently in cucumber grown there.
The FWUE estimates obtained
for cereal, vegetable, and industrial
crops indicate a wide gap between
the amount of water actually needed
and the amount applied.
Improving water-use efficiency in
the production of these crops
would save a considerable amount
of water in the areas studied.
The models showed that when
farmers had a limited supply of
water, they would allocate any extra
water available to crops with higher
water requirements, such as cotton,
tomato, potato, sugar beet, and
berseem, rather than to crops requiring
less water, such as wheat and
barley. Water allocation among different
crops was mainly determined
by output prices, the crops chosen
for planting, the area of each crop,
and the type of irrigation technology
used. Water prices had little effect
on water allocation once crops were
planted, probably because water
prices were highly subsidized in the
study areas. Large increases in water
charges would reduce the amount of
water used for irrigation, but also
adversely affect farmers’ incomes.
Using the same models,
researchers also analyzed farm-survey
data collected from 284 wheat
farmers participating in a supplemental
irrigation project in
Nineveh province, Iraq. In this
project, reducing the amount of
irrigation water used boosted
wheat yields by 58-100% and raised
water productivity (yield per unit
water used) by 31% on average.
Even in this project, however, the
average FWUE for all farms was 0.8
kg/m 3, indicating that farmers
over-irrigated their wheat by 20%
on average.
However, this average value
masked differences between different
groups of farmers. So, while
56% of the Nineveh farmers overirrigated
their wheat by 13%, 20%
of those studied over-irrigated their
crops by 36%, and a further 4%
applied 66% too much water. In
addition, another group, the
remaining 20% of farmers actually
under-irrigated their wheat. These
differences highlight the need to
develop targeted recommendations
Theme 4
Fig. 28. On-farm
water-use efficiency
(FWUE) for
different crops in
Beni Sweif and
Nubaria, Egypt.
Fig. 29. Tomato
FWUE in different
areas in WANA:
Rabea, Iraq; Al
Ghor, Jordan;
and Beni Sweif
and Nubaria,
Egypt.
for different irrigation practices of
each farmer group.
Researchers also found that
water-use efficiency in Nineveh was
greater on small farms (less than 10
hectares) and medium-sized farms
(10-20 hectares), than on large farms
(more than 20 hectares). This should
be considered when introducing supplemental
irrigation on large farms,
as farmers with large holdings overirrigated
their wheat by 28%, whereas
those with small and mediumsized
holdings over-irrigated by only
23% and 19%, respectively.
Policies are needed to encourage
the design of appropriate incentives
and technical packages for improving
water-use efficiency.
Introducing more water-efficient
irrigation technologies is one option.
Center-pivot sprinklers, for example,
used 7.2% less water than solidset
sprinklers in wheat production
in Nineveh. Sound extension strategies
are needed to optimize water
use at the farm level and reduce the
adverse effects of over-irrigation,
such as salinization and waterlogging.
This would increase crop productivity
while ensuring the sustainable
use of water and land.
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