Aims: Improving soil properties and supplying water in rangelands are critical in these areas. For this reason, rainwater harvesting (RWH) systems are commonly used to enhance water availability. Although RWH systems and soil amendments are recognized as approaches for improving soil conditions and water availability, the combined effectiveness of these measures in environments affected by industrial activities and constrained by limited moisture is not yet well understood. This study aimed to evaluate the individual and interactive effects of three RWH methods and five soil amendment types on the initial establishment of two drought-tolerant native species, Nitraria schoberi and Seidlitzia rosmarinus. The study area is located near bauxite mines in the northern part of Jajarm County, Khorasan Province, Iran.
Materials & Methods: The study investigated the effects of three RWH methods (contour furrow, pitting, and crescent‑shaped catchments) as well as soil amendment treatments (acrylic nanoclay particles, mycorrhizal fungi (Glomus intraradices, G. mosseae, and Glomus fasciculatum), wheat straw mulch, and zeolite) on improving the establishment of two native plant species, N. schoberi and S. rosmarinus, which are indigenous to the study area. For this purpose, at the end of the first growing season, establishment percentage (%), height (cm), diameter (cm), and canopy cover (cm2) were measured and analyzed. The experiment was conducted in a Completely Randomized Design with 13 replications.
Findings: Contour furrow gave the highest establishment for both species (~91% for N. schoberi, ~70% for S. rosmarinus), while crescent and pitting methods gave lower rates. For N. schoberi, RWH methods significantly affected growth traits, but soil amendments had no significant effect. For S. rosmarinus, both RWH and amendments (especially mycorrhiza and zeolite) significantly improved height and crown diameter. Overall, for N. schoberi, RWH methods (especially contour furrow) are the determining factor, and soil amendment treatments provide no additional benefit; however, for S. rosmarinus, both RWH methods and some amendments (mycorrhiza and zeolite) significantly improve plant growth.
Conclusion: Contour furrow is the most effective RWH system due to uniform runoff and infiltration. Combining RWH with suitable amendments can enhance growth of rangeland species in arid industrial areas, though long-term monitoring is recommended.