Initial Substrate Moisture Content Affects Chemical Properties of Bagged Substrates Containing Controlled Release Fertilizer at Two Different Temperatures

in HortScience

Bagged potting mixes can be stored for weeks or months before being used by consumers. Some bagged potting mixes are amended with controlled release fertilizers (CRFs). The objective of this research was to determine how initial substrate moisture content and storage temperature affect the chemical properties of bagged potting mix with CRF incorporated and stored for up to 180 days. The base substrate composed of 60 sphagnum peat: 30 bark : 10 perlite (by vol.) amended with 5.5 g·L−1 dolomitic limestone and 0.5 g·L−1 granular wetting agent. This base substrate was either not amended with additional fertilizer (control) or amended with 0.59 kg·m−3 N of a CRF (Osmocote 18N–1.3P–5K) that was either ground (CRF-G) or whole prills (CRF-P). Substrates had initial moisture contents (IMCs) of 25%, 45%, or 65% and were stored at temperatures of either 20 or 40 °C. IMC and fertilizer type affected pH, electrical conductivity (EC), and nutrient release. Substrate pH increased with increasing IMC due to greater lime reactivity. About 25% of N from CRF-G treatments was immobilized between 2 and 14 days of storage. Low moisture content of bags, due to low IMC or storage at 40 °C, reduced the rate of N release from CRF-P treatments. Substrate P was rapidly immobilized by microbial communities.

Contributor Notes

Corresponding author. E-mail: james.altland@ars.usda.gov.

Article Sections

Article Figures

  • View in gallery

    Mean moisture content (%, by weight) of bagged substrates composed of 60 sphagnum peat: 30 bark : 10 perlite by volume. Error bars represent 95% confidence intervals about the mean. Substrates had initial moisture contents (IMC) of 65%, 45%, or 25%, and the bagged substrates were stored in a growth chamber at temperatures of either 20 °C (left) or 40 °C (right) for 180 d.

  • View in gallery

    Substrate pH of bagged substrates composed of 60 sphagnum peat: 30 bark : 10 perlite by volume. Substrates were amended with 5.5 g·L−1 dolomitic limestone and had initial moisture content (IMC) of 65% (top), 45% (middle), or 25% (lower), and stored in a growth chamber set to 20 °C (left) or 40 °C (right) during 180-d storage period. Substrates were also either not amended with fertilizer (control), or amended with 0.59 kg·m−3 N of a controlled release fertilizer (CRF) (Osmocote 18N–1.3P–5K) that was either ground (CRF-G) or whole prills (CRF-P). Error bars represent the 95% confidence interval about the mean.

  • View in gallery

    Substrate EC of bagged substrates composed of 60 sphagnum peat: 30 bark : 10 perlite by volume. Substrates were either not amended with fertilizer (control) or amended with 0.59 kg·m−3 N of a controlled release fertilizer (CRF) (Osmocote 18N–1.3P–5K) that was either ground (CRF-G) or whole prills (CRF-P). Substrates had initial moisture content of 65% (higher), 45% (middle), or 25% (lower) and were stored in a growth chamber at temperatures of either 20 °C (left) or 40 °C (right). Error bars represent the 95% confidence interval about the mean.

  • View in gallery

    The recovered water extractable nitrogen (NH4+ + NO3−) from a substrate composed of 60 sphagnum peat: 30 bark : 10 perlite by volume. Data are expressed as mean percent of the total mass of 238 mg N applied via the controlled release fertilizer (CRF). Error bars represent the 95% confidence interval about the mean. Substrates were either not amended with fertilizer (control) or amended with 0.59 kg·m−3 N of a CRF (Osmocote 18N–1.3P–5K) that was either ground (CRF-G) or whole prills (CRF-P). Substrates had initial moisture contents of 65% (higher), 45% (middle), or 25% (lower) and were stored at temperatures of either 20 °C (left) or 40 °C (right).

  • View in gallery

    The recovered water extractable phosphorus (P) from a substrate composed of 60 sphagnum peat: 30 bark : 10 perlite by volume. Data are expressed as mean percent of the total mass of 39.63 mg P applied via the controlled release fertilizer (CRF). Error bars represent the 95% confidence interval about the mean. Substrates were either not amended with fertilizer (control) or amended with 0.59 kg·m−3 N of a CRF (Osmocote 18N–1.3P–5K) that was either ground (CRF-G) or whole prills (CRF-P). Substrates had initial moisture contents of 65% (higher), 45% (middle), or 25% (lower) and were stored at temperatures of either 20 °C (left) or 40 °C (right).

Article References

  • AltlandJ.E.JeongK.Y.2016Dolomitic lime amendment affects pine bark substrate pH, nutrient availability, and plant growth: A reviewHortTechnology26565573

    • Search Google Scholar
    • Export Citation
  • ApodacaL.E.2016Peat: US Geological Survey 2014 minerals yearbook. 13 Oct. 2017. <https://minerals.usgs.gov/minerals/pubs/commodity/peat/myb1-2014-peat.pdf>

  • BirrenkottB.A.CraigJ.McVeyG.R.2005A leach collection system to track the release of nitrogen from controlled-release fertilizers in container ornamentalsHortScience4018871891

    • Search Google Scholar
    • Export Citation
  • BrookesP.C.PowlsonD.S.JenkinsonD.S.1984Phosphorus in the soil microbial biomassSoil Biol. Biochem.16169175

  • CabreraR.I.1997Comparative evaluation of nitrogen release patterns from controlled-release fertilizer by nitrogen leaching analysisHortScience32669673

    • Search Google Scholar
    • Export Citation
  • CarlileW.R.2004Changes in organic growing media during storageActa Hort.648153159

  • Chang-wenD.ZhouJ.ShavivA.2006Release characteristics of nutrients from polymer-coated compound controlled release fertilizersJ. Polymer Environ.14223230

    • Search Google Scholar
    • Export Citation
  • De OliveiraS.F.FisherP.HuangJ.MelloS.2016Strategies to provide fertilizer for both production and consumer phases of petuniaHortTechnology26164175

    • Search Google Scholar
    • Export Citation
  • DickinsonK.CarlileW.R.1995The storage properties of wood-based peat-free growing mediaActa Hort.408996

  • HandreckK.A.1996Phosphorus immobilization in wood waste-based potting mediaCommun. Soil Sci. Plant Anal.2722952314

  • HuettD.O.GogelB.J.2000Longevities and nitrogen, phosphorus, and potassium release patterns of polymer-coated controlled-release fertilizer at 30 °C and 40 °CCommun. Soil Sci. Plant Anal.31959973

    • Search Google Scholar
    • Export Citation
  • HulmeF.2011The benefits of applying controlled release fertilizersGreenhouse Mgt.3116668

  • HusbyC.E.NiemieraA.X.HarrisJ.R.WrightR.D.2003Influence of diurnal temperature on nutrient release patterns of three polymer-coated fertilizersHortScience38387389

    • Search Google Scholar
    • Export Citation
  • LindsayW.L.1979Chemical equilibria in soils: Carbonate equilibria. The Blackburn Press Caldwell NJ

  • PokornyF.A.1979Pine bark container media – An overviewProc. Intl. Plant Prop. Soc.29484495

  • SaadiI.LaorY.MedinaS.KrassnovskyA.RavivM.2010Compost suppressiveness against Fusarium oxysporum was not reduced after one-year storage under various moisture and temperature conditionsSoil Biol. Biochem.42626634

    • Search Google Scholar
    • Export Citation
  • ScottM.1985Efford gives guidance on bark. Garden Centre Hort. Trade J. Jan.:11–17

  • Selmer-OlsenA.R.GislerodH.R.1986Storage of fertilized peatActa Hort.178163172

  • ShavivA.RabanS.ZaidelE.2003Modeling controlled nutrient release from polymer coated fertilizer: Diffusion release from single granulesEnviron. Sci. Technol.3722512256

    • Search Google Scholar
    • Export Citation
  • SlivkaD.C.McClureT.A.BuhrA.R.AlbrechtR.1992Compost: United States supply and demand potentialBiomass Bioenergy3281299

  • TodarK.2012Todar’s online textbook of bacteriology. 5 May 2017. <http://textbookofbacteriology.net/nutgro.html>

  • ZaccheoP.CrippaL.CattivelloC.2013Effect of controlled-release fertilizers on chemical parameters of two growing media during 12 months storageActa Hort.1013327332

    • Search Google Scholar
    • Export Citation

Article Information

Google Scholar

Related Content

Article Metrics

All Time Past Year Past 30 Days
Abstract Views 44 44 10
Full Text Views 47 47 1
PDF Downloads 3 3 0