Abstarct: Nickel is a strategic element in advanced industries and green technologies, and agromining represents a sustainable and environmentally compatible approach for its extraction. This study aimed to evaluate the feasibility of nickel agromining in the Robat-Sefid ophiolitic belt and to identify efficient native hyperaccumulator species. Three species O. inflata, O. penjwinensis, and O. callichroa were examined under semi-controlled greenhouse conditions in two distinct climatic regions, Shahroud and Ahvaz. The results indicated that the serpentinic soils of the study area are characterized by an alkaline pH ranging from 8.3 to 8.7, a low calcium-to-magnesium ratio of less than 0.4, and a high total nickel concentration of up to 2,400 mg kg⁻¹. Among the tested species, O. inflata exhibited the highest efficiency in nickel uptake and translocation, reaching a concentration of 2,195 mg kg⁻¹ Ni in the aerial tissues, with a bioconcentration factor (BCF) of 1.5 and a translocation factor (TF) of 3.53. The harvested biomass was processed through sequential steps including drying, ashing, cross-washing, acid leaching, and selective ion removal, ultimately yielding ammonium nickel sulfate hexahydrate (ANSH) as the end product. Analytical results obtained from FESEM, EDS, FTIR, and Raman spectroscopy revealed that the presence of calcium and sodium in sulfate phases reduced product purity, with the crystallization stage acting as the rate-limiting step of the process. Overall, the native species O. inflata, due to its high ecological adaptability, efficient nickel accumulation, and ability to produce an industrially valuable compound, is identified as a promising candidate for the sustainable development of nickel agromining and the advancement toward a circular economy in Iran.