Abstract:
The Punjab River System (PRS) consists of five Rivers and a net-work of canals
and inter-river canals. No doubt, such irrigation developments have brought a great
prosperity to the people by enhancing the agricultural capability of the province. On the
other hand, sodicity and salinity surfaced up as a water short, water excess dilemma.
Poor maintenance, higher cropping intensity, low delivery efficiency from canal head to
crops root zone and over-use of the system resulted in a substantive water deficit.
Consequential to water deficit, conjunctive irrigation use began to emerge Jn canal
command area (CCA). About 70% of the tubewells are estimated to pump water of
inferior quality. The Punjab development statistics show that tubewells (both in public
and private sector) increased many times. In 1996-97, 4.5 x 10s
tubewells tvere reported
against a number of 2.6 x 10s
in 1988-89. Calculations show that tubewells are adding a
salt load ® 129.06 million tons (mt) per year. Contribution from shallow water table
through capillary phenomenon further adds 0.14 mt of salts. The deployment of tubewells
at that large scale has badly disturbed the salt balance in the river basin. Canal water, no
doubt, is excellent in quality but due to restricted drainage in the irrigation basin also
adds 20.99 mt of salt load (assuming 276 g m'3
total soluble salts) every year through
55.94 million acre foot (MAF) water, allocated to the Punjab. The salt balance equations
show that salts exported out of the Punjab through Gaddu Barrage and the salts removed
through leaching and crop harvest (80.59 mt) did not match with the salt flux added
(150.19 mt) to the irrigated lands. The serious disturbance in SALT BALANCE,
groundwater being the main contributor, has inducted SECONDARY SALINITY in the
basin, which is becoming a threat and gaining a dominant position over the genetic
salinity. Presently, about 12.38% of the (CCA) is affected by salinity and sodicity. This
menace if allowed to go unchecked will turn most of the irrigated soils unproductive.
Sensing the future course of irrigated agriculture in context of slat balance therefore, has
become imperative. It is also suggested to the actors involved in irrigation management to
harness the water resources and strengthen the irrigation, drainage, research and
developmental capability of the system, so that a prosper future can be imparted to them coming generations.
