Gross N transformation rates after application of household compost or domestic sewage sludge to agricultural soil

P. Ambus, L.K. Kure, E.S. Jensen

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    Gross N mineralization and immobilization was examined in soil amended with compost and sewage sludge on seven occasions during a year using N-15 pool dilution and enrichment techniques. Gross N mineralization was initially stimulated with both wastes and accelerated through the first 112 days of incubation, peaking at 5 mg with compost compared with 4 mg in control and sludge-treated soil. The magnitudes of mineralization rates exceeded those of immobilization by on average 6.3 ( compost) and 11.4 ( sludge) times, leading to a persistent net N mineralization cumulating up to 160 mg soil(compost) and 54 mg soil (sludge) over the season from May to November. The numerical model FLUAZ comprehensively predicted rates of gross mineralization and immobilization. Sludge exhibited an early season N-release, whereas compost released only 10% of the N during the first two months of incubation. This indicates that compost should be applied well in advance of sowing in order to match crop N demands.
    Original languageEnglish
    Issue number7-8
    Pages (from-to)723-730
    Publication statusPublished - 2002
    Event11th Nitrogen workshop - Reims, France
    Duration: 9 Sep 200112 Sep 2001


    Conference11th Nitrogen workshop

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