ISHS Acta Horticulturae 342: International Symposium on Horticultural Substrates other than Soil in situ
EFFECTS OF SELF-HEATING ON BIOLOGICAL, CHEMICAL AND PHYSICAL CHARACTERISTICS OF PEAT |
| Authors: | G. Wever, M.H. Hertogh-Pon |
| Abstract:
In a stockpile of peat self-heating may occur. This process is not completely understood. In an experiment about 30 temperature sensors were placed in a stockpile of young sphagnum peat. The experiment was ended when a temperature of 70°C was reached. Samples from places with different temperatures were collected and analysed on chemical, physical and biological properties. In the first temperature stage, up to ca 50°C the quality of the peat hardly changed. In the stage from 50 – 70°C, particularly towards the end of this stage, the peat was seriously affected. Due to the decomposition high concentrations of ammonium, phosphorus, calcium and trace elements were found in the extract. The peat became a darker colour, had a special smell and occasionally became mouldy. In the extract of this peat fungal spores were found. The water absorption decreased from wetness ratio 8.0 g.g-1 to 6.5 g.g-1. A bio-assay with lettuce, garden cress, Impatiens and kohlrabi showed growth reduction. The growth reduction was less after two years' storage. Ficus was grown on peat substrates made from the different temperature stages (20, 40, 50 and 67°C). The growth on the peat of the 67°C stage was disturbed by nitrogen deficiency, caused by nitrogen absorption as a result of decomposition of the peat. | |
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