The role of organic acids on the uptake and relationship of phosphorus and zinc in corn (Zea mays L.) by application of ³²P and ⁶⁵Zn radioisotopes

ABSTRACT

To investigate the effect of oxalic and citric acids on the uptake and relationship of phosphorus and zinc in corn (Zea mays L.), some greenhouse experiments were performed by individual and combined application of monopotassium phosphate [KH₂³²PO₄] and zinc sulfate [⁶⁵ZnSO₄.7H₂O] fertilizers in microcosm. For this purpose after planting corn seeds, solutions of phosphorus (³²P) and zinc (⁶⁵Zn) (14 and 2 M) and organic acids treatments (1 and 10 mM) were injected in microcosms at suitable times. Then, plants were harvested, digested, extracted, and activity of ³²P and ⁶⁵Zn was measured in samples. Results revealed that the highest uptake of ³²P in shoots was 18.8% and observed at 10 mM concentration of oxalic acid. But no effect on ⁶⁵Zn uptake was seen and the highest uptake was observed in control (1.27%). The highest uptake of ³²P and ⁶⁵Zn in plant shoots and roots was observed at 10 mM concentration of oxalic and citric acids, respectively.

KEYWORDS:

• corn (Zea mays L.)
• organic acids
• ³²P
• ⁶⁵Zn
• uptake
• relationship

Acknowledgments

The authors would like to thank Mr. Bahram Salimi from the LSC laboratory, Mr. Moeen Meftahi, and Mr. Mehdi Yaghoobi from Gamma Spectrometry laboratory in Nuclear Science and Technology Research Institute of Iran for their help and cooperation in sample preparation and analysis. The work forms part of a thesis submitted to the University of Tarbiat Modares for the degree of Ph.D.