INFLUENCE OF ROOT TEMPERATURE ON PHYTOACCUMULATION OF As, Ag, Cr, AND Sb IN POTATO PLANTS (SOLANUM TUBEROSUM L. VAR. SPUNTA)

Abstract

Three consecutive years of field experiments were carried out to investigate the effect of root temperatures induced by the application of mulches for phytoextraction of As, Ag, Cr and Sb using potato plants (roots, tubers, stems and leaflets). Four different plastic covers were used (T1: transparent polyethylene; T2: white polyethylene; T3: white and black coextruded polyethylene; and T4: black polyethylene), taking uncovered plants as control (T0). The different treatments had a significant effect on mean root temperatures (T0 = 16°C, T1 = 20°C, T2 = 23°C, T3 = 27°C and T4 = 30°C) and induced a significantly different response in the As, Ag, Cr and Sb phytoaccumulation. The T3 treatment gave rise to the greatest phytoaccumulation of As, Ag, Cr and Sb in the roots, leaflets and tubers. In terms of the relative distribution of the phytoaccumulated metals (with respect to the total of the plant), As accumulated mainly in the roots and leaflets whereas Ag, Cr and Sb accumulated primarily in the tubers, establishing a close relationship between biomass development of each organ and phytoaccumulation capacity of elements in response to temperature in the root zone. With regard to phytoremediation using the potato plant, it is necessary to ascertain the influence and include the control of the thermal regime of the soil to optimize the phytoextraction of pollutants.

Keywords:

• Solanum tuberosum
• Root-zone temperature
• Phytoextraction
• Arsenic
• Chromium
• Silver
• Antimony

ACKNOWLEDGMENTS

The authors express their gratitude to the “Instituto Nacional de Investigación y Tecnología Agraria y Alimentaria” (INIA) and the “Dirección General de Investigación Agraria de la Consejería de Agricultura y Pesca de la Junta de Andalucía” for the financial support for this work within the framework of Research Projects “INIA 8505” and “INIA SC93-084” and to the C.I.F.A. (Centro de Investigación y Formación Agraria) for its support in the experiments, and plant and soil sampling. The authors would like to thank David Nesbitt for the translation into English, reviewing and constructive comments.