Optimizing root zone environment to enhance technology stability of “dry sowing and wet emergence” in cotton fields of southern Xinjiang, China

Abstract

In southern Xinjiang, limited precipitation and low soil moisture render the Dry Sowing and Wet Emergence (DSME) technique susceptible to instability, mainly due to uneven post-sowing irrigation and surface salinization. Thus, identifying a suitable irrigation regime for DSME is essential to regulate the root-zone environment, promote cotton germination and growth, and improve the reliability of this technique. Between 2021 and 2023, we conducted a three-year field experiment to examine DSME's impacts on soil water-heat-salt dynamics, cotton physiological characteristics, yield, and irrigation water productivity (IWP). In the third year, we implemented an enhanced irrigation strategy integrating winter drip irrigation with DSME. This included 17 seedling-stage treatments: 8, 10, and 15 mm in 2021; 5, 10, and 13 mm in 2022; and 5, 10, 13, and 15 mm in 2023. Drip frequencies varied from 1 to 4 times in 2021–2022–1–2 times in 2023. The results showed that seedling-stage irrigation amounts were significantly and positively correlated with cotton growth indices, thereby markedly increasing plant height, dry matter accumulation, and yield. Combining higher irrigation volumes with greater frequencies significantly enhanced IWP. Specifically, treatments G7, B7, and DG4 achieved 1.78, 1.81, and 1.83 kg m³ , respectively—representing increases of 16.29 %, 25.69 %, and 38.64 % over the control. In summary, integrating winter drip irrigation with DSME yielded optimal results. This approach substantially reduced agricultural water use while improving cotton yield and quality, offering a sustainable, water-efficient strategy for cultivation in southern Xinjiang's arid regions.