Introduction In arid regions with scarce water resources, water shortage constrains cotton production. “Dry sowing and wet emergence,” as a water-saving technique, promotes seed emergence by locally moistening the soil, but its application in saline-alkali areas is limited by unclear water-salt distribution patterns. This study hypothesized that optimized irrigation strategies could improve soil water-salt distribution and enhance emergence rates. Methods To test this hypothesis, this study conducted a two-year (2024 and 2025) split-plot field experiment in the arid region of Xinjiang. The main plots were irrigation frequency: P1 (single drip irrigation on the first day after sowing) versus P2 (two drip irrigations on the first and eighth days after sowing); The subplots varied total irrigation volume: W1 (15 mm), W2 (30 mm), and W3 (45 mm). Irrigation was applied as a single application in P1 and divided equally into two applications in P2. The study examined the relationship between seedling-stage soil moisture content, salinity, uniformity of water-salt distribution, desalination rate, and emergence outcomes. Results Two years of research indicate: Under identical irrigation frequencies, the W3 treatment increased soil moisture content in the 0–20 cm soil layer by 5.43% and 3.78% compared to W1 and W2, respectively. Water distribution uniformity improved, while salt content decreased by 4.76% and 11.28%, resulting in corresponding desalination rate increases of 25.02% and 7.67%. Under identical irrigation volumes, the P2 treatment exhibited a 7.42% higher soil moisture content in the 0–20 cm layer than the P1 treatment at 12 days post-sowing, with a 3.45% reduction in salinity and a 14.39% increase in emergence rate. Under synergistic regulation, the P2W2 treatment demonstrated the most optimal comprehensive performance. Compared to other treatments, it improved water uniformity by 1.05–6.28%, increased desalination rates by 15.62–32.27%, and boosted emergence rates by 5.79–13.91%. Correlation analysis revealed a significant positive correlation between emergence rate and moisture uniformity (R 2 = 0.83) and a significant negative correlation with salinity uniformity (R²=0.82). Based on these relationships, this study established critical water-salt thresholds for ensuring emergence: maintaining soil moisture content between 18.36% and 19.82% in the 0–20 cm soil layer and keeping soil salinity below 3.65 g/kg ensures a stable emergence rate above 85%. Discussion In summary, optimizing irrigation strategies (applying 15 mm of water on both the first and eighth days after sowing) improved soil water-salt distribution in the 0–20 cm soil layer by enhancing water retention capacity and promoting salt leaching, thereby increasing cotton emergence rates. This study provides theoretical and practical foundations for water-saving irrigation and water-salt regulation in cotton fields in southern Xinjiang.
Zhang et al. (Thu,) studied this question.