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Sorption Dynamics of Organic and Inorganic Phosphorus Compounds in Soil
Author(s) -
Berg A. S.,
Joern B. C.
Publication year - 2006
Publication title -
journal of environmental quality
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.888
H-Index - 171
eISSN - 1537-2537
pISSN - 0047-2425
DOI - 10.2134/jeq2005.0420
Subject(s) - sorption , chemistry , soil water , phosphate , desorption , phosphorus , environmental chemistry , adsorption , biochemistry , organic chemistry , ecology , biology
Phosphorus retention in soils is influenced by the form of P added. The potential impact of one P compound on the sorption of other P compounds in soils has not been widely reported. Sorption isotherms were utilized to quantify P retention by benchmark soils from Indiana, Missouri, and North Carolina when P was added as inorganic P (Pi) or organic P (β‐D‐glucose‐6‐phosphate, G6P; adenosine 5′‐triphosphate, ATP; and myoinositol hexaphosphate, IP 6 ) and to determine whether soil P sorption by these organic P compounds and Pi was competitive. Isotherm supernatants were analyzed for pH and total P using standard protocols, while Pi and organic P compounds were assayed using ion chromatography. Under the controlled conditions of this study, the affinity of all soils for P sources followed the order IP 6 > G6P > ATP > Pi. Each organic P source had a different potential to desorb Pi from soils, and the order of greatest to least Pi desorption was G6P > ATP > IP 6 Glucose‐6‐phosphate and ATP competed more directly with Pi for sorption sites than IP 6 at greater rates of P addition, but at the lesser rates of P addition, IP 6 actually desorbed more Pi. Inositol hexaphosphate was strongly sorbed by all three soils and was relatively unaffected by the presence of other P sources. Decreased total P sorption due to desorption of Pi can be caused by relatively small additions of organic P, which may help explain vertical P movement in manured soils. Sorption isotherms performed using Pi alone did not accurately predict total P sorption in soils.