ABSTRACT Adopting management practices that enhance biomass production and metal accumulation in hyperaccumulator species is a key strategy to improve agromining efficiency. This study evaluated the effects of mineral (NPK) and organic (cattle manure) fertilization on the growth, nutritional status, and accumulation of Ni, Co, Cr, Cu, Mn, and Zn by Berkheya coddii cultivated in ultramafic soil. The experiment was conducted in a greenhouse using a randomized block design with three treatments: control, NPK (100:100:120 kg ha -1 ), and cattle manure (5 Mg ha -1 ). Both fertilization strategies improved plant nutritional status and significantly increased biomass, with mineral fertilization (NPK) exhibiting the most pronounced effect. Although shoot Ni content declined under fertilization, particularly in the NPK treatment, this was offset by a substantial biomass gain, resulting in the highest total Ni removal (35.1 g plant -1 ), nearly double that of the control. Nickel hyperaccumulation (>1,000 mg kg -1 ) was observed in all treatments, with the highest foliar content in unfertilized plants. The NPK also enhanced the uptake of other metals, especially Co, Cr, Mn, Zn, and Cu, confirming its broader impact on trace element accumulation. These findings underscore the key role of biomass accumulation and fertilization management in maximizing phytoextraction efficiency. Future field-based studies should explore reduced fertilization rates to balance agronomic performance, economic viability, and environmental sustainability in Ni agromining systems.
Araújo et al. (Thu,) studied this question.