Fertilization regimes affecting nickel phytomining efficiency on a serpentine soil in the temperate climate zone

Abstract

Phytomining of nickel (Ni) refers to cropping of selected Ni hyperaccumulator plants on Ni-rich serpentine soils. In this study, the effect of different fertilization regimes on the Ni yield of Odontarrhena chalcidica (syn. Alyssum murale) was evaluated within a field experiment on an Austrian serpentine site. Odontarrhena chalcidica was planted in six treatments: control, fertilized by mineral fertilizer, cow manure, pig manure, compost, and planted at higher plant density. A positive fertilization effect was observed: plants treated with NPK and pig manure produced significantly higher biomass (1.9 t ha⁻¹ for both treatments). Nickel yields showed a clear trend for enhancement upon fertilization (cow manure: 22.7 kg Ni ha⁻¹, pig manure: 21.3 kg Ni ha⁻¹, NPK: 20.6 kg Ni ha⁻¹), but were not significantly different from the control. As a result of Ni accumulation in plants, DTPA-extractable Ni pools were significantly lower after harvesting (average 37.3 mg kg Ni-DTPA⁻¹) compared to the time of planting (average 45.6 mg kg Ni-DTPA⁻¹) in organic fertilization treatments and plots of higher plant density. The application of organic fertilizers contributed also to improved soil quality. We conclude that fertilization can increase the phytomining potential of field-grown Ni hyperaccumulator plants in a soil-friendly manner.

Keywords:

• Agromining
• field experiment
• hyperaccumulation

Acknowledgments

We thank Aida Bani (Agricultural University of Tirana, Albania) for providing seeds of O. chalcidica and Dieter Schranz for providing the experimental field and the cow- and pig manure. We thank the Vienna City Administration (MA 48) for providing the organic compost. We appreciate the fire brigade Bernstein for regularly supplying our field site with irrigation water. We gratefully acknowledge valuable help in the field and in the lab by Anna Biebl, Laura Quintero, Veronika Slavik and Willem van Hoesel.

Disclosure statement

No potential conflict of interest was reported by the author(s).

Additional information

Funding

This study was supported by the European Commission (AGROMINE project; LIFE15 ENV/FR/000512).