Root zone adaptive irrigation technology: A novel subsurface irrigation method using for drought-resistant afforestation in water shortage regions

Afforestation plays a critical role in boosting carbon sequestration and mitigating climate change, yet seedling survival is constrained by drought and water scarcity in water-scarce regions. To address this issue, a novel root zone adaptive irrigation (RZAI) technology was developed for drought-resistant afforestation, and three experiments were conducted acrossTashkent (Uzbekistan), Lhasa (Xizang, China) and Chengdu (Sichuan, China) to evaluate its efficacy under diverse climate features of arid, semi-arid, and semi-humid drought-prone areas, respectively. The results indicated that in arid and semi-arid regions, the soil water storage in the root zone under RZAI was significantly higher than that under the bare soil pit (CK). Particularly in Tashkent, the average soil water storage in the root zone under RZAI reached 126.9 mm, which was 1.9 times that of CK. Regarding soil temperature, CK resulted in higher temperatures than RZAI during the soil warming phase, while the opposite trend was observed during the soil cooling phase. Notably, RZAI significantly elevated the mean soil temperature in Lhasa from 13.5℃ to 18.2℃, alleviating low-temperature stress for seedlings. At the Longquan Mountain of Chengdu, the actual evapotranspiration (ETₐ) of RZAI and CK with the average daily values were 22.3 mm and 18.9 mm, respectively. Correspondingly, RZAI improved leaf water content and stem flow rate by 13.7% and 16.8% compared to CK. Across all three experimental sites, RZAI consistently demonstrated superior performance in promoting growth of seedlings, as evidenced by significantly enhanced new shoot length, ground diameter, and seedling height. Overall, this study provided a new technical approach for promoting seedlings growth in afforestation projects, especially in arid and semi-arid regions with water resource shortage.