Novel Field Data on Phytoextraction: Pre-Cultivation With Salix Reduces Cadmium in Wheat Grains

Abstract

Cadmium (Cd) is a health hazard, and up to 43% of human Cd intake comes from wheat products, since Cd accumulates in wheat grains. Salix spp. are high-accumulators of Cd and is suggested for Cd phytoextraction from agricultural soils. We demonstrate, in field, that Salix viminalis can remove Cd from agricultural soils and thereby reduce Cd accumulation in grains of wheat subsequently grown in a Salix-treated field. Four years of Salix cultivation reduce Cd concentration in the soil by up to 27% and in grains of the post-cultivated wheat by up to 33%. The higher the plant density of the Salix, the greater the Cd removal from the soil and the lower the Cd concentration in the grains of post-cultivated wheat, the Cd reduction remaining stable several years after Salix cultivation. The effect occurred in both sandy and clayey soil and in winter and spring bread wheat cultivars. Already one year of Salix cultivation significantly decrease Cd in post grown wheat grains. With this field experiment we have demonstrated that phytoextraction can reduce accumulation of a pollutant in post-cultivated wheat and that phytoextraction has no other observed effect on post-cultivated crops than reduced uptake of the removed pollutant.

keywords::

• agricultural soil
• field investigation
• low cadmium in wheat
• phytoextraction with Salix

Acknowledgments

The Swedish Farmers’ Foundation for Agricultural Research and the Foundation in Memory of Oscar and Lili Lamm funded this work. We gratefully acknowledge personnel at the Swedish Rural Economy and Agricultural Societies’ Brunnby research farm and at the Swedish University of Agricultural Science's Torslunda research station. Lucas Sjölén, Dr. Muhammad Tariq Javed, Arifin Sandhi, Dr. Beata Dabrowska, and Dr. Claes Bergqvist are thanked for their contribution to the field work.