MODERATELY DECOMPOSED PEAT AS A STRUCTURE BUILDER FOR YOUNGER PEATS IN GROWING MEDIA

M. Prasad, M.J. Maher
Potting media manufacturers often add a certain amount of H5 peat to younger peats to reduce shrinkage. This is important for longer term crops. Trials were conducted to study if the addition of H5 peats would reduce the shrinkage of the growing medium. Peats having H2 to H4 degree of decomposition produced by two methods –milled and sod- were tested on their own or mixed 50:50 with H5 peat and incubated on a glasshouse bench with ebb and flood irrigation for 21 months. Shrinkage was measured 4 times. Samples were taken initially and analysed for FTIR and lignin content. Bulk density and colour measurements were also carried out. FTIR analysis was also carried out at the end of the experiment. Peat type, peat x rate and peat rate were all significant. The addition of H5 peat to the other peats resulted in a decrease of shrinkage except for one H4 peat (Latvian sod). After 21 months, the trend was the same as after 9 months, except that the rate of shrinkage of the mixed materials and the Latvian sod was relatively faster than the other peats in the second half of the experiment. There were significant correlation between 1600/1056, 1600/2900 spectra at the start of the trial, lignin, fibre content, bulk density and colour measurements and the 4 shrinkage measurements. Some of the colour parameters gave the best correlation. FTIR spectra at the end of the trial were not related to shrinkage.
Prasad, M. and Maher, M.J. (2008). MODERATELY DECOMPOSED PEAT AS A STRUCTURE BUILDER FOR YOUNGER PEATS IN GROWING MEDIA. Acta Hortic. 779, 185-190
DOI: 10.17660/ActaHortic.2008.779.22
https://doi.org/10.17660/ActaHortic.2008.779.22
substrate, shrinkage, breakdown, lignin, FT-IR, H4¿5 peat, H2 to H4 peats, sod peat, milled peat
English

Acta Horticulturae