Rainwater harvesting outperforms traditional site preparation methods for restoring semiarid sites with Black locust in western Türkiye

Introduction Intensified drought in the Mediterranean Basin poses challenges for conventional afforestation. Rainwater harvesting (RWH) is a climate‐adaptive solution that restores soil hydrological functions and buffers seedlings against drought in semiarid ecosystems. Objectives This study compared RWH methods (Negarim Microcatchments and crescent bunds) with conventional methods (buror terraces and pit planting) to assess their effects on soil moisture dynamics and the 1‐year survival and growth of Black locust ( Robinia pseudoacacia L.) seedlings, a common afforestation species in semiarid sites. Methods A randomized complete block design with four replications was employed at a degraded site in Izmir, Türkiye. Each block contained 35 × 45 m experimental plots, including 35 Negarims (6 × 6 m), 30 crescent bunds (6 m radius), 11 row‐conventional terraces (45 m × 1.7 m), and 165 standard control pits (30 × 15 × 20 cm). One‐year‐old seedlings were planted at 3 × 3 m spacing. Soil moisture content, seedling survival rate, percent height, and root‐collar diameter (RCD) growth were measured after 1 year. Results RWH treatments, both group and individual, maintained significantly higher soil moisture than terraces and pits, delaying summer moisture depletion and extending the growing season. The RWH treatment group significantly increased seedling survival rate, percent RCD, and height growth. Individually, Negarims provided significantly greater percent RCD and height growth than pit planting. Seedlings at the base of Negarims and crescents had significantly greater percent RCD growth and survival rates than those in other planting positions. Conclusions RWH structures, particularly Negarims, are essential nature‐based solutions for securing drought‐resilient afforestation.