Measuring the fate of compost-derived phosphorus in native soil below urban gardens

Gaston E. Small, Sara Osborne, Paliza Shrestha, Adam Kay

Research output: Contribution to journalArticlepeer-review

1 Scopus citations


The heavy reliance on compost inputs in urban gardening provides opportunities to recycle nutrients from the urban waste stream, but also creates potential for buildup and loss of soil phosphorus (P). We previously documented P in leachate from raised-bed garden plots in which compost had been applied, but the fate of this P is not known. Here, we measured P concentrations in soils below four or six-year-old urban garden plots that were established for research. We hypothesize that the soil P concentration and depth of P penetration will increase over time after gardens are established. Soil cores were collected in five garden plots of each age and quantified for inorganic weakly exchangeable P. Inorganic weakly exchangeable P was significantly elevated in native soil below garden plots (>35 cm deep) relative to reference soil profiles, and excess P decreased with increasing depth, although differences between garden plots of different ages were not significant. Our analysis shows that excess P from compost accumulates in native soil below urban garden plots. While urban agriculture has the potential to recycle P in urban ecosystems, over-application of compost has the potential to contribute to soil and water pollution.

Original languageEnglish (US)
Article number3998
JournalInternational journal of environmental research and public health
Issue number20
StatePublished - Oct 2 2019

Bibliographical note

Funding Information:
Funding: This research was funded by a National Science Foundation CAREER award (award number 1651361) to G.S.


  • Garden
  • Leachate
  • Nutrient
  • Phosphorus
  • Soil
  • Urban agriculture

Fingerprint Dive into the research topics of 'Measuring the fate of compost-derived phosphorus in native soil below urban gardens'. Together they form a unique fingerprint.

Cite this