Effects of Irrigation on Survival and Growth of Haloxylon ammodendron in Semi-arid Region of Tajikistan

An appropriate irrigation regime is essential for successful afforestation in arid or semi-arid regions such as Tajikistan because water is a critical limiting factor for vegetation establishment. This study aimed to examine the effects of irrigation on survival and growth of H. ammodendron seedlings in Shahrtuz, Tajikistan. In 2021, 1-year-old containerized or bare-root seedlings were planted in the study area, which consists of three sites; planted in May (site 1), November (site 2) and December (site 3). Except for unirrigated zones, all sites were irrigated once a month (1-1.5 L seedling-1 month-1) after planting. In July 2022, three irrigated plots (IR) and one unirrigated plot (UIR) were selected from each site, and the survival rate (%), height (cm), and root collar diameter (RCD; mm) were measured for all H. ammodendron in 12 m 🞩 20 m plots. In all sites, the survival rate of seedlings was 46 % (site 1), 65 % (site 2), and 54 % (site 3) higher in IR compared to UIR; however, the differences were not statistically significant. The irrigation showed no influences on the height and RCD of seedlings in sites 1 and 2. On the other hand, in site 3, both growth indicators were higher in UIR compared to IR (height [IR = 35.43 ± 15.03 cm, UIR = 46.69 ± 14.23 cm]; RCD [IR = 2.39 ± 1.02 mm, UIR = 4.94 ± 2.55 mm]). The irrigation brought no significant effects in our study, which implies that the current irrigation regime may not be enough to influence the survival and growth of the seedlings. Further studies are required under diverse irrigation regimes to develop promising strategies for vegetation establishment in arid or semi-arid regions.