Technical and economic evaluation of the deficit irrigation on yield of cotton

A field experiment was carried out over two years to investigate the effects of deficit irrigation applied with surface and subsurface drip irrigation systems on water use efficiency and yield of cotton. The experiments were carried out during 2014-2015 in Kerman Province (Iran) in a split plot based on a randomized complete block design with three replications. Treatments considered three levels of irrigation, based on 100 (L1, full irrigation), 80 (L2) and 60 (L3) percent of crop water demand at each irrigation event, as main plots, as well as two drip irrigation methods, including surface (S1) and subsurface (S2), as subplots. All treatments were assessed in terms of yield, water use efficiency, as well as of economic aspects, including investment preference determination. Two-year comparison showed that yield, water use efficiency, boll weight, number of boll and plant height in subsurface drip irrigation system (S2) were increased 10.8, 11, 7.45, 12.8 and 11.2 percent compared to surface drip irrigation system (S1), respectively. Economic analysis showed that applying 100 percent of crop water requirement in subsurface drip irrigation (L1S2) was superior to the other treatments. Acknowledgement