Objective: The study was done to explore the effects of different mulched drip irrigation modes on cotton evapotranspiration, and to provide reference for design of technical parameters of drip irrigation and determination of irrigation schedule. Method: A laboratory simulation experiment was carried out to obtain the cotton evapotranspiration by weighing method, and then the effects of different emitter discharges (0.3, 0.8 L/h), irrigation water qualities (0.40, 2.47, 3.50 g/L), and irrigation amounts (321,386 mm) on cotton evapotranspiration were analyzed. Result: The cotton evapotranspiration under small emitter discharge (0.3 L/h) is higher than that under large emitter discharge (0.8 L/h) when the cotton is irrigated with sufficient fresh water. For the same irrigation amount and emitter discharge, the cotton evapotranspiration is almost the same under fresh water (0.40 g/L) and brackish water irrigation (2.47 g/L), which is obviously lower than the cotton evapotranspiration under saline water irrigation (3.50 g/L). For the same emitter discharge, the cotton with sufficient water supply has higher evapotranspiration than that with deficient water supply. Conclusion: The cotton evapotranspiration decreases with the increase of emitter discharge or mineralization degree of irrigation water, increases with the increase of irrigation amount. The blackish water irrigation with proper amount can not influence the cotton evapotranspiration significantly.
