Managing Scarce Water Resources in Agriculture in West Asia and North Africa - Restorative Redevelopment of Devastated Ecocultural Landscapes - page 452

under such conditions. Fortunately, the two tracks, water and land efficiencies, are
parallel for some distance, but not all the way. Irrigating for less than maximum yield
per unit land (deficit irrigation) could save substantial amounts of water for irrigating
new lands and hence producing more food from the available water. Deficit irrigation
is not the only practice that has shown good potential, but other ways are available
to modify water management principles to achieve more water-efficient practices.
Research is needed to develop the required soil-water-plant-atmosphere relations
under such conditions. New guidelines for crop water requirements and irrigation
scheduling to maximize water productivity are yet to be developed for the important
crops in the dry areas.
C hanging C Urrent l and U se
Due to increased water scarcity, globalization, and climate change, current land use
and cropping patterns should be modified if more food is to be produced from less
water (see chapter 4). Water is likely to be the major constraint and new land use
systems that respond to external as well as internal factors must be developed based
on available water. This should include adopting water efficient crops, varieties, and
sound combinations of crops in the farming system.
P reCision i irrigation
Improved technologies that already exist may at least double the amount of food
produced from present levels of water use, if applied in the field. Implementing
precision irrigation, such as micro- and sprinkler irrigation systems, laser leveling,
and other techniques contributes to substantial improvement in water application
and distribution efficiency. It is true that water lost during conveyance and on-
farm application is not an absolute loss from a basin perspective, but its quality
may deteriorate and its recovery comes at a cost. To account for these losses, the
size of the irrigation system will significantly increase and this again comes at
a very high cost. Policies to implement and transfer these technologies are vital.
There is a need to provide farmers with economic and more efficient alternatives
to on-farm water management practices with incentives that can bring about the
needed change. There is a great scope for improving the productivity and use effi-
ciency of water in the region. Research findings have shown that substantial and
sustainable improvements in water productivity are attainable, but can only be
achieved through integrated natural resources management approaches. On-farm
water use efficient techniques if coupled with improved irrigation management
options, better crop selection and appropriate cultural practices, improved genetic
makeup, and timely socioeconomic interventions will help to achieve this objec-
tive. Conventional water management guidelines designed to maximize yield per
unit area need to be revised for achieving maximum water productivity instead.
Appropriate policies on farmers' participation and water cost recovery are neces-
sary for adopting improved management options.