Effect of irrigation water salt content on cotton growth and yield

A split-plot design was adopted in an irrigation experiment before cotton sowing with irrigation water amount as the main treatment and water mineral salinity as sub-treatments. The experiment results showed that the rate of cotton emergence decreased with increased irrigation water salt content. The rate of cotton emergence was over 90% at 4 g·L^-1 of irrigation water salinity. At 6 g·L^-1 of irrigation water salinity, cotton emergence was 85%, but delayed. The optimum irrigation range was 22.5~34.0 mm. Inhibitory actions of water salt on cotton growth and development at early stage was more obvious than at late stage. There was no significant difference in cotton yield between the fresh water and salt water (<3.38 g·L^-1) irrigation. At irrigation water salinity >3.38 g·L^-1, cotton yield linearly dropped. Yield was, however, much higher at irrigation water salinity <8 g·L^-1 than that under rainfed conditions.