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Phosphorus exchange properties of European soils and sediments derived from them
Author(s) -
Hartikainen H.,
Rasa K.,
Withers P. J. A.
Publication year - 2010
Publication title -
european journal of soil science
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.244
H-Index - 111
eISSN - 1365-2389
pISSN - 1351-0754
DOI - 10.1111/j.1365-2389.2010.01295.x
Subject(s) - sorption , soil water , sediment , desorption , saturation (graph theory) , environmental chemistry , eutrophication , phosphorus , surface runoff , chemistry , soil science , environmental science , nutrient , geology , adsorption , geomorphology , ecology , mathematics , organic chemistry , combinatorics , biology
The sorption and desorption of phosphorus (P) from eroding soil particles in land runoff are important processes contributing to agriculturally‐driven eutrophication. We investigated the P‐exchange properties and related chemical characteristics of contrasting European agricultural soils and sediment material eroded from them under indoor (small‐scale) and outdoor (larger‐scale) rainfall simulations. Quantity‐intensity ( Q / I ) relationships revealed large variation in equilibrium P concentrations at zero net P sorption ( EPC 0 ) (0–10.3 mg l −1 ) and instantly labile P (− Q 0 , the amount of P to be desorbed to obtain a P equilibrium concentration of 0 mg l −1 ) (2–75 mg kg −1 ), both correlating closely with Al‐bound P and the P saturation degree of Al oxides (DPS Alox ). Maximum P sorption ( Q max ) (43–515 mg kg −1 ) also correlated most closely with Al ox . The indoor and outdoor rainfall simulations produced sediments with different P sorption properties: in the indoor simulation (less kinetic energy, constant slope), the sediments had larger EPC 0 values, and usually larger − Q 0 values, than the sediments in the outdoor simulation (greater kinetic energy, variable slopes). Furthermore, the P exchange properties of the sediments differed from those of the bulk soil depending on the enrichment of soil P‐sorption components (Fe/Al oxides, clay). The outdoor simulation indicated that sites with gentle slopes produced sediments that were more enriched with Al ox , Fe ox , Mn ox and organic C than those with steeper slopes. In this study, when the bulk soil had an initial EPC 0 greater than 1.3 mg l −1 , the outdoor rainfall simulation produced sediment with smaller EPC 0 and vice versa , indicating that, depending on the P status of the bulk soil, the sediment material was acting as source or sink for P during transport. However, on the basis of their EPC 0 values, most eroding sediments might be expected to desorb, rather than adsorb, P when entering surface water.