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Research output: Contribution to Journal/Magazine › Journal article › peer-review
Research output: Contribution to Journal/Magazine › Journal article › peer-review
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TY - JOUR
T1 - Organic Acids Regulation of Chemical-Microbial Phosphorus Transformations in Soils
AU - Menezes-Blackburn, Daniel
AU - Paredes, Cecilia
AU - Zhang, Hao
AU - Giles, Courtney D.
AU - Darch, Tegan
AU - Stutter, Marc
AU - George, Timothy S.
AU - Shand, Charles
AU - Lumsdon, David
AU - Cooper, Patricia
AU - Wendler, Renate
AU - Brown, Lawrie
AU - Blackwell, Martin
AU - Wearing, Catherine
AU - Haygarth, Philip M.
PY - 2016/11/1
Y1 - 2016/11/1
N2 - We have used an integrated approach to study the mobility of inorganic phosphorus (P) from soil solid phase as well as the microbial biomass P and respiration at increasing doses of citric and oxalic acid in two different soils with contrasting agronomic P status. Citric or oxalic acids significantly increased soil solution P concentrations for doses over 2 mmol kg-1. However, low organic acid doses (<2 mmol kg-1) were associated with a steep increase in microbial biomass P, which was not seen for higher doses. In both soils, treatment with the tribasic citric acid led to a greater increase in soil solution P than the dibasic oxalic acid, likely due to the rapid degrading of oxalic acids in soils. After equilibration of soils with citric or oxalic acids, the adsorbed-to-solution distribution coefficient (Kd) and desorption rate constants (k-1) decreased whereas an increase in the response time of solution P equilibration (Tc) was observed. The extent of this effect was shown to be both soil and organic acid specific. Our results illustrate the critical thresholds of organic acid concentration necessary to mobilize sorbed and precipitated P, bringing new insight on how the exudation of organic acids regulate chemical-microbial soil phosphorus transformations.
AB - We have used an integrated approach to study the mobility of inorganic phosphorus (P) from soil solid phase as well as the microbial biomass P and respiration at increasing doses of citric and oxalic acid in two different soils with contrasting agronomic P status. Citric or oxalic acids significantly increased soil solution P concentrations for doses over 2 mmol kg-1. However, low organic acid doses (<2 mmol kg-1) were associated with a steep increase in microbial biomass P, which was not seen for higher doses. In both soils, treatment with the tribasic citric acid led to a greater increase in soil solution P than the dibasic oxalic acid, likely due to the rapid degrading of oxalic acids in soils. After equilibration of soils with citric or oxalic acids, the adsorbed-to-solution distribution coefficient (Kd) and desorption rate constants (k-1) decreased whereas an increase in the response time of solution P equilibration (Tc) was observed. The extent of this effect was shown to be both soil and organic acid specific. Our results illustrate the critical thresholds of organic acid concentration necessary to mobilize sorbed and precipitated P, bringing new insight on how the exudation of organic acids regulate chemical-microbial soil phosphorus transformations.
U2 - 10.1021/acs.est.6b03017
DO - 10.1021/acs.est.6b03017
M3 - Journal article
C2 - 27700099
AN - SCOPUS:84994252352
VL - 50
SP - 11521
EP - 11531
JO - Environmental Science and Technology
JF - Environmental Science and Technology
SN - 0013-936X
IS - 21
ER -