TY - JOUR
T1 - Characterization of leached phosphorus from soil, manure, and manure-amended soil by physical and chemical fractionation and diffusive gradients in thin films (DGT)
AU - Glæsner, Nadia Andersen
AU - Donner, Erica
AU - Magid, Jakob
AU - Rubæk, Gitte Holton
AU - Zhang, Hao
AU - Lombi, Enzo
PY - 2012/10/2
Y1 - 2012/10/2
N2 - We are challenged to date to fully understand mechanisms controlling phosphorus (P) mobilization in soil. In this study we evaluated physical properties, chemical reactivity, and potential bioavailability of P mobilized in soil during a leaching event and examined how the amounts and properties of leached P were influenced by surface application of cattle manure. Leaching experiments on manure itself, and on intact soil columns (14.1 cm inner dia., 25 cm height) before and after manure application, were carried out at an irrigation rate of 1 mm h-1 for 48 h. High concentrations of dissolved reactive P (DRP) were found in manure leachates (up to 32 mg L -1), whereas concentrations of P in soil leachates were low both before and after manure application (around 0.04 mg L-1 before application and up to 0.4 mg L-1 afterward). This result indicates that the soil retained most of the P added with manure. Manure particles themselves were also largely retained by the soil. Combined physical (centrifugation) and chemical (molybdate reactiveness) fractionation of leached P showed that leachates in the manure treated soils were dominated by dissolved unreactive P (DUP), mainly originating from manure. However, centrifugation only removed a small fraction of total particles from the leachates, indicating that the so-called dissolved fraction may be associated with low density particulate matter. Deployment of Diffusive Gradients in Thin films (DGT) devices in the leachates proved to be a good approach for measuring reactive P in soil leachates. The results indicated that total reactive P (TRP) gave a better estimate of potentially bioavailable P than both total P (TP) and DRP in these experiments.
AB - We are challenged to date to fully understand mechanisms controlling phosphorus (P) mobilization in soil. In this study we evaluated physical properties, chemical reactivity, and potential bioavailability of P mobilized in soil during a leaching event and examined how the amounts and properties of leached P were influenced by surface application of cattle manure. Leaching experiments on manure itself, and on intact soil columns (14.1 cm inner dia., 25 cm height) before and after manure application, were carried out at an irrigation rate of 1 mm h-1 for 48 h. High concentrations of dissolved reactive P (DRP) were found in manure leachates (up to 32 mg L -1), whereas concentrations of P in soil leachates were low both before and after manure application (around 0.04 mg L-1 before application and up to 0.4 mg L-1 afterward). This result indicates that the soil retained most of the P added with manure. Manure particles themselves were also largely retained by the soil. Combined physical (centrifugation) and chemical (molybdate reactiveness) fractionation of leached P showed that leachates in the manure treated soils were dominated by dissolved unreactive P (DUP), mainly originating from manure. However, centrifugation only removed a small fraction of total particles from the leachates, indicating that the so-called dissolved fraction may be associated with low density particulate matter. Deployment of Diffusive Gradients in Thin films (DGT) devices in the leachates proved to be a good approach for measuring reactive P in soil leachates. The results indicated that total reactive P (TRP) gave a better estimate of potentially bioavailable P than both total P (TP) and DRP in these experiments.
U2 - 10.1021/es301861a
DO - 10.1021/es301861a
M3 - Journal article
C2 - 22934573
SN - 0013-936X
VL - 46
SP - 10564
EP - 10571
JO - Environmental Science & Technology
JF - Environmental Science & Technology
IS - 19
ER -