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Molecular Speciation of Phosphorus Present in Readily Dispersible Colloids from Agricultural Soils
Author(s) -
Liu Jin,
Yang Jianjun,
Liang Xinqiang,
Zhao Yue,
Cade-Menun Barbara J.,
Hu Yongfeng
Publication year - 2014
Publication title -
soil science society of america journal
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.836
H-Index - 168
eISSN - 1435-0661
pISSN - 0361-5995
DOI - 10.2136/sssaj2013.05.0159
Subject(s) - xanes , genetic algorithm , soil water , colloid , phosphorus , chemistry , oryza sativa , environmental chemistry , absorption (acoustics) , nuclear magnetic resonance spectroscopy , spectroscopy , nuclear chemistry , stereochemistry , materials science , organic chemistry , biology , geology , biochemistry , soil science , ecology , physics , quantum mechanics , gene , composite material
Speciation of colloidal P (P coll ) is vital yet little known. For the first time ever, the P species in readily released colloids from agricultural soils were determined by P K‐edge X‐ray absorption near‐edge structure (XANES) and solution 31 P nuclear magnetic resonance (P‐NMR) spectroscopy. Water‐dispersible P coll was the dominant fraction of readily released P (<1 μm) from the studied soils cultivated with rice ( Oryza sativa L.) (RS; 80.9%) and vegetables (VS; 55.1%). The P coll in these samples was predominantly in inorganic form, which XANES showed to be moderately labile Fe‐ and Al‐associated P (total 70.4–83.3%) and nonlabile hydroxyapatite (16.8–19.7%). The P‐NMR analysis showed that the dominant organic P compound class in colloids from RS was orthophosphate monoesters, of which inositol hexakisphosphate was the largest component. These results strongly suggested that colloids are richer in stable P forms and poorer in labile and mineralizable P than the bulk soils.