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Sustainable management of biosolid phosphorus: a field study
Author(s) -
Withers P. J. A.,
Flynn N. J.,
Warren G. P.,
Taylor M.,
Chambers B. J.
Publication year - 2016
Publication title -
soil use and management
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.709
H-Index - 81
eISSN - 1475-2743
pISSN - 0266-0032
DOI - 10.1111/sum.12235
Subject(s) - biosolids , soil water , loam , environmental science , eutrophication , soil type , phosphorus , lime , soil classification , agronomy , environmental chemistry , environmental engineering , nutrient , soil science , chemistry , geology , paleontology , organic chemistry , biology
Stabilized wastewater biosolids are a renewable resource for improving soil and crop quality, but their regular application can rapidly elevate soil available phosphorus (P) (e.g. Olsen‐P[OP]) leading to increased transfer of soluble reactive P ( SRP ) in land run‐off causing eutrophication. To assess the eutrophication risk of biosolid P recycling, 143 arable fields with different biosolid P input histories, and representing different soil type and biosolid type combinations, were sampled and their P chemistry determined. Differences in soil total P between the surveyed fields were used as the best measure of net biosolid P inputs. Rates of soil OP increase (range 3–11% of soil total P, mean 7%) were lowest on a P‐fixing soil and tended to increase more on sandy soils (6–9%) and on loamy soils receiving biosolids dosed with both iron (Fe) and lime (9–11%). Potential release of SRP to run‐off was measured as water‐extractable P ( WEP ) and varied widely (6–52% of soil OP). WEP concentrations were lowest on clayey soils, and where biosolids containing P‐binding elements [calcium (Ca) or Fe, but not together] were applied. The relationship between OP and WEP was therefore highly dependent on both soil type and biosolid type. However, analysis of soil P sorption parameters indicated that eutrophication risk on loamy and clayey soils was significantly reduced when OP represented <20% of the soil P sorption capacity. Our results suggest that biosolids could be more sustainably managed by matching biosolid type to soil type and P fertility status.