TY - JOUR
T1 - Phosphate stable oxygen isotope variability within a temperate agricultural soil
AU - Granger, Steven J.
AU - Harris, Paul
AU - Peukert, Sabine
AU - Guo, Rongrong
AU - Tamburini, Federica
AU - Blackwell, Martin S A
AU - Howden, Nicholas J K
AU - McGrath, Steve
PY - 2017/1/1
Y1 - 2017/1/1
N2 - In this study, we conduct a spatial analysis of soil total phosphorus (TP), acid extractable phosphate (PO4) and the stable oxygen (O) isotope ratio within the PO4 molecule (δ18OPO4 ) from an intensively managed agricultural grassland site. Total P in the soil was found to range from 736 to 1952 mg P kg− 1, of which between 12 and 48% was extractable using a 1 M HCl (HClPO4 ) solution with the two variables exhibiting a strong positive correlation. The δ18OPO4 of the extracted PO4 ranged from 17.0 to 21.6‰ with a mean of 18.8‰ (± 0.8). While the spatial variability of Total P has been researched at various scales, this is the first study to assess the variability of soil δ18OPO4 at a field-scale resolution. We investigate whether or not δ18OPO4 variability has any significant relationship with: (i) itself with respect to spatial autocorrelation effects; and (ii) HClPO4 , elevation and slope - both globally and locally. Results indicate that δ18OPO4 was not spatially autocorrelated; and that δ18OPO4 was only weakly related to HClPO4 , elevation and slope, when considering the study field as a whole. Interestingly, the latter relationships appear to vary in strength locally. In particular, the δ18OPO4 to HClPO4 relationship may depend on the underlying soil class and/or on different field managements that had operated across an historical north-south field division of the study field, a division that had been removed four years prior to this study.
AB - In this study, we conduct a spatial analysis of soil total phosphorus (TP), acid extractable phosphate (PO4) and the stable oxygen (O) isotope ratio within the PO4 molecule (δ18OPO4 ) from an intensively managed agricultural grassland site. Total P in the soil was found to range from 736 to 1952 mg P kg− 1, of which between 12 and 48% was extractable using a 1 M HCl (HClPO4 ) solution with the two variables exhibiting a strong positive correlation. The δ18OPO4 of the extracted PO4 ranged from 17.0 to 21.6‰ with a mean of 18.8‰ (± 0.8). While the spatial variability of Total P has been researched at various scales, this is the first study to assess the variability of soil δ18OPO4 at a field-scale resolution. We investigate whether or not δ18OPO4 variability has any significant relationship with: (i) itself with respect to spatial autocorrelation effects; and (ii) HClPO4 , elevation and slope - both globally and locally. Results indicate that δ18OPO4 was not spatially autocorrelated; and that δ18OPO4 was only weakly related to HClPO4 , elevation and slope, when considering the study field as a whole. Interestingly, the latter relationships appear to vary in strength locally. In particular, the δ18OPO4 to HClPO4 relationship may depend on the underlying soil class and/or on different field managements that had operated across an historical north-south field division of the study field, a division that had been removed four years prior to this study.
KW - Phosphorus
KW - Grassland
KW - Spatial analysis
KW - GW model
KW - North Wyke farm platform
UR - http://www.scopus.com/inward/record.url?scp=84989237435&partnerID=8YFLogxK
U2 - 10.1016/j.geoderma.2016.09.020
DO - 10.1016/j.geoderma.2016.09.020
M3 - Article (Academic Journal)
C2 - 28050050
SN - 0016-7061
VL - 285
SP - 64
EP - 75
JO - Geoderma
JF - Geoderma
ER -