Agriculture Reference
In-Depth Information
applying 300 mm of water to wheat and cotton (instead of the current
practice of 420 mm) is enough to produce optimal crop yields without in-
creasing salinity levels in the soil. This saving can be achieved by reduc-
ing amounts of individual irrigations. Based on their fi eld experiments,
Choudhary and Qureshi (1991) have also shown that improved irrigation
management techniques such as furrow-bed and furrow-ridge can reduce
irrigation requirements by 40%. They have recommended an irrigation
application of 260-300 mm for wheat and cotton crops to achieve optimal
yields.
TABLE 1:
Comparison of total water use and water savings under current and improved
irrigation practices (Data source: Punjab Agriculture Department)
Crop
Area (ha)
Current irrigation
practices
Improved irrigation
practices
Total water
saving (BCM)
Irrigation
(mm)
Total water
use (BCM)
Irrigation
(mm)
Total water
use (BCM)
Wheat
8 578 000
480
41.2
300
25.7
15.5
Cotton
3 100 000
480
14.9
300
9.4
5.5
Rice
1 016 000
1 600
16.3
1 300
13.3
3.0
Total
72.4
48.4
24.0
Prathapar and Qureshi (1999) used the Soil-Water-Atmosphere-Plant
(SWAP) model (Van Dam et al., 1997) to simulate optimal irrigation
schedules for wheat and cotton crops. They found that irrigation appli-
cations can be reduced to 80% of the total crop evapotranspiration (ET)
without compromising on yields and soil salinization, and recommended
300-320 mm as the optimal irrigation amount for wheat and cotton crops.
Similarly improved irrigation methods for rice such as direct seeding also
reduce irrigation amounts by 15-20% (Qureshi et al., 2006). The amount
of water applied to rice was 1200 mm as compared to the 1870 mm usually
applied under traditional planting. High effi ciency irrigation methods such
as drip and sprinkler systems have also proved successful in increasing
water use effi ciency. However, in a country like Pakistan where continu-
ous availability of water and energy are big issues, adoption of these tech-
