Immobilization of agricultural phosphorus in temperate floodplain soils of Illinois, USA

Mary R. Arenberg, Xinqiang Liang, Yuji Arai

Research output: Contribution to journalArticlepeer-review

Abstract

Nutrient losses from Mississippi watersheds degrade downstream water bodies. As forested floodplains intercept agricultural drainage waters, a limiting nutrient like phosphorus (P) could potentially be sequestered in forest soils, reducing P loss to the Gulf of Mexico. Thus far, the role of temperate deciduous floodplain soils for P has not been extensively investigated in the Midwestern United States. The objective of this study was to investigate the buffering capacity of P in floodplain soils using soil biochemical chemical assays, 31P nuclear magnetic resonance spectroscopy (NMR) and P K-edge X-ray absorption near edge structure spectroscopy (XANES). Phosphorus reaction dynamics were compared between floodplains and surrounding upland soils in east-central Illinois, USA. Total organic P was significantly greater in the floodplain (277.27 ± 159.51 mg kg−1) than that in the upland (113.04 ± 74.88 mg kg−1), illustrating its buffering capacity. Notably, microbial biomass P (averaged 13.08 mg kg−1) was greater in the floodplain than that in the upland. The results of 31P NMR analysis showed the presence of organic P (e.g., orthophosphate monoesters) and orthophosphate. The P K-edge XANES analysis shows that these inorganic and organic P species are predominantly adsorbed in calcite and precipitated as calcium phosphate in floodplain soils. These findings suggest that temperate deciduous floodplain soils have a great potential to immobilize agricultural P in the Upper Mississippi watershed.

Original languageEnglish (US)
Pages (from-to)257-278
Number of pages22
JournalBiogeochemistry
Volume150
Issue number3
DOIs
StatePublished - Oct 1 2020

Keywords

  • Alfisol
  • Floodplains
  • Forest soils
  • Immobilization
  • Mollisol
  • Nutrient buffering
  • P cycling
  • Phosphorus

ASJC Scopus subject areas

  • Environmental Chemistry
  • Water Science and Technology
  • Earth-Surface Processes

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