La Trobe
2017 ChengMM Chemo 188,689.pdf (461.74 kB)

Ammonium-based fertilizers enhance Cd accumulation in Carpobrotus rossii grown in two soils differing in pH

Download (461.74 kB)
journal contribution
posted on 2021-01-06, 01:07 authored by Miaomiao Cheng, Anan Wang, Caixian TangCaixian Tang
© 2017 Elsevier Ltd Nitrogen fertilization has been shown to improve Cd uptake by plants but there is little information on the effect of N form. This study examined the effects of N form on Cd bioavailability and phytoextraction in two soils differing in pH. Plants of halophytic species Carpobrotus rossii were grown in an acidic Sodosol [pH (CaCl2) 4.9] and a neutral Vertosol (pH 7.2) spiked with 20 mg kg−1 Cd as CdCl2. Three N forms, KNO3, (NH4)2SO4 and (NH2)2CO at a rate of 24 mg N kg−1 were applied at weekly intervals, together with nitrification inhibitor dicyanodiamide. Cadmium availability was measured, and Cd speciation in the rhizosphere analysed using synchrotron-based X-ray absorption spectroscopy. The uptake, translocation and accumulation of Cd in plants were also assessed. The reduced N forms (NH4+ and urea), compared to NO3−-N, decreased rhizosphere pH by 0.25 units in Sodosol and 0.72 units in Vertosol, but decreased Cd-phosphate (by 23%) only in the Vertosol. Moreover, the reduced N forms increased the extractable Cd concentration in the rhizosphere of the Vertosol by 92% and of the Sodosol by 14%. They increased root Cd concentration by 70% and Cd uptake per unit root length by 40% in the Vertosol, and increased the translocation of Cd from the roots to the shoots by 76% in the Sodosol. The results suggest that the supply of NH4+-based N favors Cd phytoextraction in C. rossii.


We thank Dr Chengjun Zhang for his assistance to setup the experiment. Part of this research was undertaken on the XAS beamline at the Australian Synchrotron (AS162/XAS/10855), Victoria, Australia. M.M. Cheng is supported by the International Postgraduate Research Scholarship and Australian Postgraduate Awards.


Publication Date







8p. (p. 689-696)





Rights Statement

The Author reserves all moral rights over the deposited text and must be credited if any re-use occurs. Documents deposited in OPAL are the Open Access versions of outputs published elsewhere. Changes resulting from the publishing process may therefore not be reflected in this document. The final published version may be obtained via the publisher’s DOI. Please note that additional copyright and access restrictions may apply to the published version.