Improved root-zone hydration and soil moisture conservation enhance drought resilience during the establishment of young tea plants (Camellia sinensis L.)

<title>Abstract</title> <p> Background and aims Recurrent drought and limited availability of irrigation water severely constrain the establishment of young tea plants in the tea growing regions of Bangladesh. Prolonged drought depletes root-zone soil moisture, resulting in complete mortality in newly transplanted tea saplings. This study aimed to investigate soil moisture conservation techniques capable of alleviating drought stress and maximizing the survival, growth and physiological performance of young tea plants. Methods Ten root-zone soil water management techniques—combining scheduled watering with or without aboveground mulching, belowground mulching and the water bagging approach under limited-water conditions—were tested for the first time on newly transplanted tea saplings during winter drought from 6 December 2025 to 13 March 2026. Saplings were planted following randomized complete block design. Results Kaplan‒Meier survival analysis revealed that checked saplings without mulching and limited watering resulted in complete mortality within 18 days, whereas supplemental watering every 10- or 15-day interval without or with aboveground mulching maintained 100% survival throughout the period. Subsurface mulching with water hyacinth roots ( <italic>Pontederia crassipes</italic> ) or black polythene film under limited-water conditions maintained a final survival rate of 80–90%, whereas water bagging substantially delayed mortality and achieved a final survival rate of 65%. These strategies preserved relatively high root-zone soil moisture, accelerated shoot emergence, enhanced gas exchange, reduced root proline, and maintained a relatively low leaf-to-air VPD, indicating improved plant water status under extreme drought. Conclusion Integrating root-zone hydration and soil moisture conservation markedly improved the survival and early establishment of young tea plants, providing water-efficient strategies for drought-resilient tea cultivation. </p>