Abstract:
Karkheh River Basin (KRB)
is one of the important basins in Iran
regarding water resources, where both rain
fed and irrigated agricultural production
systems prevail. Water logging and soil
salinity are the major threats to water
productivity and sustainable agricultural
production in the lower KRB (L-KRB).
More than 78% of agricultural production in
Dasht-e Azadegan region is dominated by
grains, mainly wheat and barley. The main
objective of this research was to determine
and evaluate water productivity (WP) of
irrigated wheat, as major cultivated crop in
DA and recommendation of simple and
applicable management guidelines. This
research was conducted in fourteen
farmers’fields, typical of the farms in the
region, during cropping season of two years
2005-2006 and 2006-2007. Based on the
total applied water, calculated Evaporation-
Transpiration (ET), and crop yield, wheat
water productivity values were calculated
and determined. Analysis of measured
Water Productivity (WP) indicated that the
range of variation in WP values is relatively
high and varies between 0.1-2.1 kg.m-3 In
the southern parts of L-KRB, mainly in
Dasht-e Azadegan plain (DA), available
data show that the problem of soil salinity is
magnified due to lack of farmers’
knowledge, inadequate drainage networks,
and absence of improved farming practices.
In general, the main cause of soil salinity in
the L-KRB is high water table, usually
varying between 1.2-3.0 m below the soil
surface. Evaluation of results indicates that,
inefficiencies and the limiting factors
affecting WP in southern part of L-KRB.
