Journal article

Publication year: 2020

Pages: 3231-3246

Journal: Environmental Geochemistry and Health

Volume number: 42

Issue number: 10

ISSN: 0269-4042

eISSN: 1573-2983

Open access status: Hybrid

DOI Link: https://doi.org/10.1007/s10653-020-00561-y

Publisher: Springer

Abstract: 
Controlled drainage is considered as a soil management tool to improve water supply to crops and reduce nutrient losses from fields; however, its closure may affect phosphorus (P) mobilization in soil. To assess the P mobilization potential, three soil profiles with redoximorphic features were selected along a slight hill in Northern Germany. Soil samples from three depths of each profile were characterized for basic properties, total element content, oxalate- and dithionite-extractable pedogenic Al, Fe and Mn (hydr)oxides, P pools (sequential extraction), P species [P K-edge X-ray absorption near-edge structure (XANES) spectroscopy] and P sorption behavior. In topsoil (similar to 10 cm depth), labile P (H2O-P + resin-P + NaHCO3-P) accounted for 26-32% of total P (P-t). Phosphorus K-edge XANES revealed that up to 49% of P-t was bound to Al and/or Fe (hydr)oxides, but sequential fractionation indicated that > 30% of this P was occluded within sesquioxide aggregates. A low binding capacity for P was demonstrated by P sorption capacity and low K-f coefficients (20-33 mg1-nfLnfkg-1) of the Freundlich equation. In the subsoil layers (similar to 30 and similar to 65 cm depth), higher proportions of Al- and Fe-bound P along with other characteristics suggested that all profiles might be prone to P mobilization/leaching risk under reducing conditions even if the degree of P saturation (DPS) of a profile under oxic conditions was < 25%. The results suggest that a closure of the controlled drainage may pose a risk of increased P mobilization, but this needs to be compared with the risk of uncontrolled drainage and P losses to avoid P leaching into the aquatic ecosystem.

Harvard Citation style: Baumann, K., Shaheen, S., Hu, Y., Gros, P., Heilmann, E., Morshedizad, M., et al. (2020) Speciation and sorption of phosphorus in agricultural soil profiles of redoximorphic character, Environmental Geochemistry and Health, 42(10), pp. 3231-3246. https://doi.org/10.1007/s10653-020-00561-y

APA Citation style: Baumann, K., Shaheen, S., Hu, Y., Gros, P., Heilmann, E., Morshedizad, M., Wang, J., Wang, S., Rinklebe, J., & Leinweber, P. (2020). Speciation and sorption of phosphorus in agricultural soil profiles of redoximorphic character. Environmental Geochemistry and Health. 42(10), 3231-3246. https://doi.org/10.1007/s10653-020-00561-y