Putting back what we take out, but how much Phosphorus and nitrogen additions to farmed Leucadendron 'Safari Sunset' and Leucospermum 'Succession' (Proteaceae)

H. Hawkins, H. Hettasch, Michael Cramer

    Research output: Contribution to journalArticle

    12 Citations (Scopus)

    Abstract

    Proteaceae are adapted to low-nutrient soils in the various regions where they occur. However, harvesting of flowering stems for the cut-flower industry must eventually cause soil nutrient depletion sufficient to reduce yields. Different N forms, and N and P concentrations were supplied to two Proteaceae cultivars (Leucadendron 'Safari Sunset' and Leucospermum 'Succession') in a controlled ferfigation experiment, and appropriate concentrations for maximum growth with minimum nutrient accumulation or loss were determined. Small additions of N (0.025-0.1 mM) significantly improved growth of both cultivars growing on Strandveld sandy soil. Larger additions of N (up to 2 MM N) resulted in poor growth (both cultivars) and N accumulation in the soil (Safari Sunset). Small additions of P (< 10 mu M) significantly improved growth of both cultivars and resulted in no accumulation or loss of P in the soil. Larger additions of P (up to 500 mu M) resulted in poor growth, P toxicity symptoms and P leaching from the upper soil layers. Best N forms in descending order of both plant visual appearance and vegetative yield were: urea >= ammonium nitrate > ammonium sulphate > calcium nitrate. Phosphorus toxicity symptoms were associated with increased concentrations of leaf P, Ca and Fe. Under conditions of maximum growth (10 mu M P and 0.1 mM N) Safari Sunset removed 18 +/- 0.6 g N, 1.5 +/- 0.1 g P, 5.3 +/- 0.6 g K and Succession removed 5.5 +/- 0.2 g N, 0.3 +/- 0.02 g P, 3.1 +/- 0.5 g K over 6 months. At maximum growth, plants acquired more N and P amounts than were supplied, but supplying higher N and P concentrations adversely affected growth. Thus, a more complex or slow-release form of N and P than urea and soluble phosphate, respectively, may provide enough N and P to replace losses from the farm soil at the low concentrations required for proteas. (c) 2006 Published by Elsevier B.V.
    Original languageEnglish
    Pages (from-to)378-388
    JournalScientia Horticulturae
    Volume111
    Issue number4
    DOIs
    Publication statusPublished - 2007

    Fingerprint

    Leucospermum
    Leucadendron
    Proteaceae
    phosphorus
    soil nutrients
    cultivars
    nitrogen
    calcium nitrate
    cut flowers
    ammonium nitrate
    ammonium sulfate
    sandy soils
    signs and symptoms (plants)
    soil
    urea
    plant growth
    phosphates
    toxicity
    flowering
    industry

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    title = "Putting back what we take out, but how much Phosphorus and nitrogen additions to farmed Leucadendron 'Safari Sunset' and Leucospermum 'Succession' (Proteaceae)",
    abstract = "Proteaceae are adapted to low-nutrient soils in the various regions where they occur. However, harvesting of flowering stems for the cut-flower industry must eventually cause soil nutrient depletion sufficient to reduce yields. Different N forms, and N and P concentrations were supplied to two Proteaceae cultivars (Leucadendron 'Safari Sunset' and Leucospermum 'Succession') in a controlled ferfigation experiment, and appropriate concentrations for maximum growth with minimum nutrient accumulation or loss were determined. Small additions of N (0.025-0.1 mM) significantly improved growth of both cultivars growing on Strandveld sandy soil. Larger additions of N (up to 2 MM N) resulted in poor growth (both cultivars) and N accumulation in the soil (Safari Sunset). Small additions of P (< 10 mu M) significantly improved growth of both cultivars and resulted in no accumulation or loss of P in the soil. Larger additions of P (up to 500 mu M) resulted in poor growth, P toxicity symptoms and P leaching from the upper soil layers. Best N forms in descending order of both plant visual appearance and vegetative yield were: urea >= ammonium nitrate > ammonium sulphate > calcium nitrate. Phosphorus toxicity symptoms were associated with increased concentrations of leaf P, Ca and Fe. Under conditions of maximum growth (10 mu M P and 0.1 mM N) Safari Sunset removed 18 +/- 0.6 g N, 1.5 +/- 0.1 g P, 5.3 +/- 0.6 g K and Succession removed 5.5 +/- 0.2 g N, 0.3 +/- 0.02 g P, 3.1 +/- 0.5 g K over 6 months. At maximum growth, plants acquired more N and P amounts than were supplied, but supplying higher N and P concentrations adversely affected growth. Thus, a more complex or slow-release form of N and P than urea and soluble phosphate, respectively, may provide enough N and P to replace losses from the farm soil at the low concentrations required for proteas. (c) 2006 Published by Elsevier B.V.",
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    doi = "10.1016/j.scienta.2006.11.010",
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    Putting back what we take out, but how much Phosphorus and nitrogen additions to farmed Leucadendron 'Safari Sunset' and Leucospermum 'Succession' (Proteaceae). / Hawkins, H.; Hettasch, H.; Cramer, Michael.

    In: Scientia Horticulturae, Vol. 111, No. 4, 2007, p. 378-388.

    Research output: Contribution to journalArticle

    TY - JOUR

    T1 - Putting back what we take out, but how much Phosphorus and nitrogen additions to farmed Leucadendron 'Safari Sunset' and Leucospermum 'Succession' (Proteaceae)

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    AU - Cramer, Michael

    PY - 2007

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    N2 - Proteaceae are adapted to low-nutrient soils in the various regions where they occur. However, harvesting of flowering stems for the cut-flower industry must eventually cause soil nutrient depletion sufficient to reduce yields. Different N forms, and N and P concentrations were supplied to two Proteaceae cultivars (Leucadendron 'Safari Sunset' and Leucospermum 'Succession') in a controlled ferfigation experiment, and appropriate concentrations for maximum growth with minimum nutrient accumulation or loss were determined. Small additions of N (0.025-0.1 mM) significantly improved growth of both cultivars growing on Strandveld sandy soil. Larger additions of N (up to 2 MM N) resulted in poor growth (both cultivars) and N accumulation in the soil (Safari Sunset). Small additions of P (< 10 mu M) significantly improved growth of both cultivars and resulted in no accumulation or loss of P in the soil. Larger additions of P (up to 500 mu M) resulted in poor growth, P toxicity symptoms and P leaching from the upper soil layers. Best N forms in descending order of both plant visual appearance and vegetative yield were: urea >= ammonium nitrate > ammonium sulphate > calcium nitrate. Phosphorus toxicity symptoms were associated with increased concentrations of leaf P, Ca and Fe. Under conditions of maximum growth (10 mu M P and 0.1 mM N) Safari Sunset removed 18 +/- 0.6 g N, 1.5 +/- 0.1 g P, 5.3 +/- 0.6 g K and Succession removed 5.5 +/- 0.2 g N, 0.3 +/- 0.02 g P, 3.1 +/- 0.5 g K over 6 months. At maximum growth, plants acquired more N and P amounts than were supplied, but supplying higher N and P concentrations adversely affected growth. Thus, a more complex or slow-release form of N and P than urea and soluble phosphate, respectively, may provide enough N and P to replace losses from the farm soil at the low concentrations required for proteas. (c) 2006 Published by Elsevier B.V.

    AB - Proteaceae are adapted to low-nutrient soils in the various regions where they occur. However, harvesting of flowering stems for the cut-flower industry must eventually cause soil nutrient depletion sufficient to reduce yields. Different N forms, and N and P concentrations were supplied to two Proteaceae cultivars (Leucadendron 'Safari Sunset' and Leucospermum 'Succession') in a controlled ferfigation experiment, and appropriate concentrations for maximum growth with minimum nutrient accumulation or loss were determined. Small additions of N (0.025-0.1 mM) significantly improved growth of both cultivars growing on Strandveld sandy soil. Larger additions of N (up to 2 MM N) resulted in poor growth (both cultivars) and N accumulation in the soil (Safari Sunset). Small additions of P (< 10 mu M) significantly improved growth of both cultivars and resulted in no accumulation or loss of P in the soil. Larger additions of P (up to 500 mu M) resulted in poor growth, P toxicity symptoms and P leaching from the upper soil layers. Best N forms in descending order of both plant visual appearance and vegetative yield were: urea >= ammonium nitrate > ammonium sulphate > calcium nitrate. Phosphorus toxicity symptoms were associated with increased concentrations of leaf P, Ca and Fe. Under conditions of maximum growth (10 mu M P and 0.1 mM N) Safari Sunset removed 18 +/- 0.6 g N, 1.5 +/- 0.1 g P, 5.3 +/- 0.6 g K and Succession removed 5.5 +/- 0.2 g N, 0.3 +/- 0.02 g P, 3.1 +/- 0.5 g K over 6 months. At maximum growth, plants acquired more N and P amounts than were supplied, but supplying higher N and P concentrations adversely affected growth. Thus, a more complex or slow-release form of N and P than urea and soluble phosphate, respectively, may provide enough N and P to replace losses from the farm soil at the low concentrations required for proteas. (c) 2006 Published by Elsevier B.V.

    U2 - 10.1016/j.scienta.2006.11.010

    DO - 10.1016/j.scienta.2006.11.010

    M3 - Article

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    EP - 388

    JO - Scientia Horticulturae: an international journal

    JF - Scientia Horticulturae: an international journal

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    IS - 4

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