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Phosphorus Reactions and Leaching Potential in Soils Amended with Sewage Sludge
Author(s) -
Siddique Muhammad Tariq,
Robinson J. Stephen,
Alloway Brian J.
Publication year - 2000
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/jeq2000.00472425002900060028x
Subject(s) - soil water , monocalcium phosphate , leaching (pedology) , chemistry , sorption , fertilizer , sewage sludge , amendment , saturation (graph theory) , environmental chemistry , desorption , phosphorus , phosphate , sewage , adsorption , zoology , environmental engineering , soil science , environmental science , mathematics , organic chemistry , combinatorics , fishery , fish <actinopterygii> , law , political science , fish meal , biology
The objective of this study was to evaluate the leaching potential of P from a range of sewage sludge‐ or P fertilizer (monocalcium phosphate)‐amended topsoils that had different P contents. Leaching trials (70 d) were conducted in 30‐cm‐long PVC columns; P‐related parameters were then determined at different depths in the leached soils. In most cases, more ( P < 0.01) P was released from the P‐fertilized than sludge‐treated soils. Increasing native Olsen P from 15 to 62 mg kg −1 had negligible effect on P release; however, there was a sharp increase in P leached between 92 and 134 (maximum) mg Olsen P kg −1 . This increase was much greater in the P‐fertilized than sludge‐treated soils. At all depths in all leached soils, resin P decreased in the order: P fertilized > sludge > control. At the lowest depth (16–20 cm) of the leached soil, the degree of P sorption saturation decreased in the same order and was related curvilinearly ( P < 0.001) to cumulative P leached (at 70 d). This relationship demonstrates the importance of P sorption saturation in controlling P leaching in sludge‐ and fertilizer‐treated soils. The more rapid rate of P saturation and P leaching in P‐fertilized than sludge‐treated soils emphasizes the role of the P source in adsorption‐desorption processes.