Implications of wheat farming in Cd(II) and Pb(II) contaminated red eutrophic Oxisol: an experimental pilot investigation

Abstract

SummaryThis study aimed (i) to assess the environmental problems of wheat farming in Oxisol with Cd and Pb below the acceptable levels established by national and international regulations, questioning their possible permissiveness; (ii) to investigate the metal distribution in wheat plant organs, and to predict possible implications of cultivation in hazardous conditions; (iii) to assess the grain and flour content of metals and to predict possible implications. The growth of plants, gas exchange parameters, nutritional composition, the yield of grains and metal distribution were evaluated. Cd and Pb are accumulated in different plant organs even when the legislation's limits are respected. 74% of Cd and 96% of Pb are accumulated in roots, while 3% of Cd and <1% of Pb are accumulated in grains. Cd and Pb caused nutritional disorders such as decreased foliar K, Ca, Cu, Zn, Fe and Mn, decreased canopy height, number of tillers, number of spikes, the volume of roots, aerial dry mass and yield of grains. Even if the established limits of Cd are respected, the flour will overtake the provisional tolerable monthly intake established by World Health Organisation. In the evaluated conditions, wheat cultivation in Oxisol within the national standard for Cd could result in hazardous levels in flour.