Agriculture Reference
In-Depth Information
nologies will remain a challenge, especially for small farmers (Qureshi et
al., 2010). For this reason, on-farm water conservation techniques which
are less costly and energy intensive should be encouraged more.
To summarize the results of the above studies, these results suggest
that 300mm of irrigation water for wheat and cotton and 1300mm for
the rice crop is suffi cient to produce optimal yields under the existing soil
and climatic conditions of the Indus basin. Table 1 compares the irrigation
amounts, total water use and water savings for current and optimized ir-
rigation practices.
Table1 clearly shows that adoption of the above-mentioned irriga-
tion practices for wheat, cotton and rice can save up to 24 BCM of water,
which is about 14% of the total renewable water available in the Indus
basin. Applying these improved irrigation techniques to other crops can
further reduce the water demand for irrigation and stress on groundwater.
Under the current surface-water-scarce conditions of the Indus basin, this
water is contributed through groundwater extraction, as is evident from
the declining groundwater table conditions in most of the canal commands
(Figure 2). Farmers with access to groundwater tend to apply more irriga-
tion water than those farmers fully relying on surface water (Shah et al.,
2003). Reducing groundwater extraction by 24 BCM will reduce diesel
consumption by 2.2 billion litres (62%) and CO
2
emissions by about 40%
(1.5 MMT of CO
2
). With these reductions, total consumption of diesel will
be reduced to 1.3 billion litres and CO
2
emissions to 2.3 MMT of CO
2
.
These calculations have been made assuming an irrigation application ef-
fi ciency of 65%. Under the furrow irrigation method (the most widely
practised in the Indus basin) irrigation effi ciency ranged between 65 and
95% with an attainable level of 85% (United States Department of Ag-
riculture (USDA)). Therefore greater water savings can be achieved by
implementing optimized irrigation schedules together with advanced farm
levelling, application rate control, and other management options.
The above analysis demonstrates that the adoption of improved irriga-
tion practices will not only help in reducing energy consumption and CO
2
emissions but will be a big step forward in stabilizing aquifers. Adoption
of these improved practices requires a shift in the thinking of farmers from
“maximizing crop production” with increased irrigation supplies to “opti-
mize crop production” with minimum irrigation supplies. Such a change
