APPARENT AND REAL WATER PRODUCTIVITY FOR COTTON-WHEAT ZONE OF PUNJAB, PAKISTAN

Water productivity need to be enhanced in view of diminishing water supplies. A study was conducted to assess the existing water productivity status in cotton-wheat cropping zone in Punjab Province of Pakistan and identifying factors for its improvement. Six watercourses on four distributaries taking off from Lower Bari Doab Canal (LBDC) of river Ravi were selected in tehsil Kabirwala, district Khanewal. The data regarding crop yield, irrigation water, fertilizer and pesticides was recorded from farmers and cross checked with information collected from Patwaris. The results indicated that mean yield, apparent water productivity (yield/irrigation water) and real water productivity (yield/water evapotranspired) for wheat was 3210 kg ha^-1, 0.43 kg m^-3 and 1.12 kg m^-3, respectively. The corresponding values for cotton were 2675 kg ha^-1, 0.22 kg m^-3 and 0.26 kg m^-3, respectively. It was concluded that all the three considered factors (irrigation water, fertilizer and pesticide) improved real water productivity (yield/water evapotranspired). Further pesticide in wheat and fertilizer in cotton was the most effective. However, water productivity studies on the larger scale and inclusion of factors (irrigation method, soil fertility, crop variety, irrigation scheduling etc.) influencing water productivity are recommended for future to improve water productivity.