Exchangeable ammonium and nitrate from different nitrogen fertilizer preparations in polyacrylamide-treated and untreated agricultural soils

Jeanine L. Kay-Shoemake, Maribeth E Watwood, Lisa Kilpatrick, Krista Harris

Research output: Contribution to journalArticle

11 Scopus citations

Abstract

High molecular weight, anionic polyacrylamide (PAM) is currently being used as an irrigation water additive to significantly reduce soil erosion associated with furrow irrigation. PAM contains amide-N, and PAM application to soils has been correlated with increased activity of soil enzymes, such as urease and amidase, involved in N cycling. Therefore we investigated potential impacts of PAM treatment on the rate at which fertilizer N is transformed into NH4/+ and NO3/- in soil. PAM-treated and untreated soil microcosms were amended with a variety of fertilizers, ranging from common rapid-release forms, such as ammonium sulfate [(NH4)2SO4] and urea, to a variety of slow-release formulations, including polymerized urea and polymer-encapsulated urea. Ammonium sulfate was also tested together with the nitrification inhibitor dicyandiamide (DCD). The fertilizers were applied at a concentration of 1.0 mg g-1, which is comparable to 100 lb acre-1, or 112 kg ha-1. Potassium chloride-extractable NH4/+-N and NO3/--N were quantified periodically during 2-4 week incubations. PAM treatment had no significant effect on NH4/+ release rates for any of the fertilizers tested and did not alter the efficacy of DCD as a nitrification inhibitor. However, the nitrification rate of urea and encapsulated urea-derived NH4/+ -N was slightly accelerated in the PAM-treated soil.

Original languageEnglish (US)
Pages (from-to)245-248
Number of pages4
JournalBiology and Fertility of Soils
Volume31
Issue number3-4
StatePublished - Jun 2000
Externally publishedYes

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Keywords

  • Dicyandiamide
  • Nitrogen fertilizer
  • Polyacrylamide
  • Polymer-encased urea
  • Polymerized urea

ASJC Scopus subject areas

  • Soil Science

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