Managing Scarce Water Resources in Agriculture in West Asia and North Africa - Restorative Redevelopment of Devastated Ecocultural Landscapes - page 464

are easily understood by farmers and project managers. Methods based on soil water
measurements and on plant-stress indicators present some difficulties, particularly
for farmers. Tensiometers and plant indicators provide information on the irrigation
date only. The farmer still needs information on how much water to apply. Farmers
are always criticized for being wasteful and applying excessive water. Actually, the
root cause behind this inefficient practice is that the farmer does not know how to
measure water flow or quantity, therefore he is applying more than what is needed in
order to be on the safe side.
In long-established irrigated areas, lands are threatened by rising water tables and
salinization. Deterioration of water quality (mainly due to intensive use of chemi-
cals and fertilizers) and quantity add to the problem. Despite today's understanding
and the availability of preventive and remedial technologies, the problems of water
logging and salinity continue to spread in the region. As a result, the productivity
of land and water resources is steadily declining and sustainability is at risk, if not
already collapsed, as indicated by land abandonment and migration to nearby cities.
Irrigation water in dry areas usually carries large amounts of dissolved salts.
Therefore, hundreds of millions of tons of salt are added to soil by irrigation water
each year in the study area. When water, but not salts, is removed from soil by
plant roots absorption and soil surface evaporation, the salt is left over in the soil
profile. This process is repeated each irrigation, thus concentration of harmful
salts in the plant root zone accumulates with time and will build up to a fatal
degree. This of course is one of the root causes resulting in salinization and land
degradation, which threatens the sustainability of irrigated agriculture. It is well
known that the protective measure to this danger is providing proper drainage and
enough salt leaching.
Drainage is the cornerstone to sustainable irrigated agriculture. Provision of
efficient drainage (especially, subsurface) with adequate leaching in any irrigated
agriculture in the arid region is of prime importance and the key for sustainable
development. In an attempt to cut down on the initial cost of developing an irrigated
agriculture project, the drainage system and related facilities are often deleted from
implementation and thus not constructed with the excuse that it is not necessary
right now or in the near future. Quite often, the drainage system is already there in
the project, but badly neglected with no proper maintenance, thus it is practically
nonexistent. There are numerous examples for each of these cases in the WANA
region. Overlooking or purposely avoiding, for cost reasons, the inclusion of drain-
age facilities in irrigated agricultural projects has resulted in agricultural disasters in
the region due to water logging and soil salinization.
W ater h arvesting for the d rier e nvironments —s tePPe
The drier environments, the steppe or rangeland, or, as called in West Asia, Al Badia ,
occupy the vast majority of the dry areas of the world. The disadvantaged people
generally live there. The natural resources of these areas are subject to degradation
and the income of the people who depend mainly on grazing is continuously declin-
ing. Due to harsh conditions, people are increasingly migrating from these areas to
the cities, with associated high social and environmental costs. Precipitation is low,