REGULAR ARTICLE Uptake of rare earth elements by citrus plants from phosphate fertilizers Christian Turra & Elisabete A. De Nadai Fernandes & Márcio Arruda Bacchi & Gabriel Adrián Sarriés & Andrés Enrique Lai Reyes Received: 31 October 2018 /Accepted: 30 January 2019 # Springer Nature Switzerland AG 2019 Abstract Background and Aims Rare earth elements (REE) are a group of the periodic table formed by 17 chemical elements (lanthanoids plus yttrium and scandium). They have been used in different field applications. In agri- culture, they can be found in some phosphate fertilizers at levels one or two orders of magnitude higher than those found in normal agricultural soils. Citrus plants are known to present high levels of REE when com- pared to most other species, however, there is little information about bioavailability of REE in phosphate fertilizers for citrus plants. This work focuses on the study of REE behavior by the application of increasing doses of single superphosphate fertilizer in Rangpur lime (Citrus limonia Osbeck) plants in a greenhouse study. Methods The technique used was instrumental neutron activation analysis (INAA). Results The results showed that the fertilizer has caused significant increases in the content of REE in the citrus plant tissues, with higher concentrations in leaves than in branches. The highest substrate-leaf transfer factor was observed for La (0.0047), though the concentrations in the plants followed the same order found in the substrate, i.e. Ce > La > Sm > Eu > Sc. Conclusion There was an increase of rare earth ele- ments concentrations in Rangpur lime plants by super- phosphate fertilizer application. Keywords Rare earth elements . Citrus plants . Lanthanoids . Phosphate fertilizers . Bioavailability Introduction The group of rare earth elements (REE) is composed by lanthanoids (La, Ce, Pr, Nd, Pm, Sm, Eu, Gd, Tb, Dy, Ho, Er, Tm, Yb and Lu) plus Y and Sc. They have similar physical and chemical properties (Henderson 1984) and are trivalent, with exception of some elements that present two different oxidation states, i.e. Ce (3+ and 4+), Sm (2+ and 3+), Eu (2+ and 3+), Nd (3+ and Plant Soil https://doi.org/10.1007/s11104-019-03979-1 Responsible Editor: Juan Barcelo. C. Turra : E. A. De Nadai Fernandes : M. A. Bacchi (*) Centro de Energia Nuclear na Agricultura, Universidade de São Paulo (CENA/USP), Avenida Centenário, 303, Piracicaba, SP 13416-000, Brazil e-mail: mabacchi@cena.usp.br C. Turra e-mail: agrochri2010@gmail.com E. A. De Nadai Fernandes e-mail: lis@cena.usp.br G. A. Sarriés : A. E. L. Reyes Escola Superior de Agricultura Luiz de Queiroz, Universidade de São Paulo (ESALQ/USP), Avenida Pádua Dias, 11, Piracicaba, SP 13418-900, Brazil G. A. Sarriés e-mail: gasarrie@usp.br A. E. L. Reyes e-mail: lai@usp.br