Response of cotton (Gossypium hirsutum) to single and paired row method of sowing under drip and furrow irrigation in saline vertisols

A field experiment was conducted during 2004-2006 to study the response of cotton (Gossypium hirsutum L.) to various level of drip and furrow irrigation in saline vertisols. The canal water (EC cw,0.20 dS/m) and well water (EC ww, 4.0 dS/m) was used for furrow and drip irrigation respectively. Crop performance was better under drip compared to furrow method of irrigation. The highest (1.34 tonnes/ha) and lowest 1.10 tonnes/ha) seed cotton yield were recorded in case of drip irrigation at 1.2 evapotranspiration in single row method and furrow irrigation at 1.0 evapotranspiration in paired row method of sowing, respectively. Net saving in irrigation water through drip irrigation was 13.8 and 10.6% at the irrigation levels of 1.0 evapotranspiration and 1.2 evapotranspiration, respectively compared to the same level of irrigation through furrow method. The highest (17.19 kg/ha-cm) and lowest (13.00kg/ha-cm) water production efficiencies were achieved in case of paired row method of sowing at 1.0 evapotranspiration through drip irrigation and 1.2 evapotranspiration through furrow irrigation, respectively. In drip irrigation, higher gross benefit: cost ratio and net profit/cm of water used was achieved under paired row method of sowing than the single row method due to reduction in system cost. To minimize the system cost of drip irrigation (up to 35%) without reductions in yield and net economic returns, one could adopt paired roe method of sowing in cotton in saline vertosols. Even though the gross B:C ratio are marginally less in drip irrigation than furrow irrigation, use of poor quality groundwater through drip irrigation seems to be a feasible solution, especially in water scarcity area.