Open AccessMolecular speciation and transformation of soil legacy phosphorus with and without long-term phosphorus fertilization: Insights from bulk and microprobe spectroscopy
Author(s) -
Jin Liu,
Jianjun Yang,
Barbara J. CadeMenun,
Yongfeng Hu,
Jumei Li,
Chang Peng,
Yibing Ma
Publication year - 2017
Publication title -
scientific reports
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.24
H-Index - 213
ISSN - 2045-2322
DOI - 10.1038/s41598-017-13498-7
Subject(s) - soil water , xanes , environmental chemistry , human fertilization , fractionation , phosphorus , genetic algorithm , chemistry , electron microprobe , agronomy , spectroscopy , mineralogy , environmental science , soil science , biology , ecology , physics , organic chemistry , quantum mechanics
Soil legacy phosphorus (P) represents a substantial secondary P resource to postpone the global P crisis. To fully utilize this P reserve, the transformation of legacy P speciation in a black soil with and without P fertilization for 27 years was investigated by chemical fractionation, molecular-level bulk (P K-edge X-ray absorption near-edge, XANES; solution 31 P nuclear magnetic resonance) and microprobe (µ-X-ray fluorescence and µ-XANES) spectroscopy. Results from both fractionation and P bulk-XANES concordantly indicated that Ca 2 -P [Ca(H 2 PO 4 ) 2 ] acts as a reserve of labile P in response to soils with or without P fertilization. Cropping for 27 years depleted hydroxyapatite while enriched iron-bound P in soils irrespective of P application. Similar accumulation of soil organic P (P o ), probably due to root residue inputs, occurred in both soils with and without P fertilization; the accumulated P o was present as orthophosphate diesters in soils with P fertilization more than in soils without P fertilization, suggesting that the release of labile P o was triggered by soil P deficits. These results provide vital information for agronomically and environmentally sustainable P management by demonstrating the potential crop availability of legacy soil P, which could reduce future P fertilization.