Sustainable management of biosolid phosphorus: a field study. (June 2016)

• Record Type: Journal Article
• Authors: Withers, P. J. A.; Flynn, N. J.; Warren, G. P.; Taylor, M.; Chambers, B. J.
• Is Part Of: Soil use and management. Volume 32(2016:Jun.)Supplement 1
• Page Start: 54
• Page End: 63
• Publication Date: 2016-06
• Subjects: Biosolids -- phosphorus -- eutrophication -- sustainable management; Soil management -- Periodicals; 631.4
• DOI: 10.1111/sum.12235
• Languages: English
• ISSNs: 0266-0032

Abstract

Abstract: 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.