[Effects of irrigation regimes on the variation of soil water and salt and yield of mechanically harvested cotton in Southern Xinjiang, China].

The expansion of soil salinization area is a threat to cotton production in Southern Xinjiang. How to control soil salt accumulation by developing precise irrigation strategy is currently a hot topic for the film mulching drip-irrigated cotton field. With aims for soil quality improvement and high yield, we investigated the effects of irrigation regimes on soil water and salt distribution, yield and fiber quality in major cotton production area of Southern Xinjiang. Results showed that the increase of irrigation amount contributed to a higher cotton photosynthetic product accumulation, but had no significant effect on the ratio of reproductive organs to total biomass. The degree of soil desa-lination had a positive correlation with the irrigation quotas. When the seasonal total irrigation amount exceeded 2577.83 m3·hm-2, soil salinization would not deteriorate. Irrigation amount had significant effect on WUEI, but had no effect on fiber quality. With the increasing of irrigation amount, cotton yield increased first and then decreased. In conclusion, applying 4200 m3·hm-2 seasonal irrigation amount in total and 7 d and 5 d irrigation interval for the budding and flowering stage respectively could be a suitable irrigation regime for mechanically-harvested cotton in the arid area of Southern Xinjiang.