Articles
COMPARISON OF THE PHYSICAL PROPERTIES OF VERMICOMPOST FROM PAPER MILL SLUDGE AND GREEN COMPOST AS SUBSTITUTES FOR PEAT-BASED POTTING MEDIA
Article number
819_25
Pages
227 – 234
Language
English
Abstract
The properties of vermicompost, green compost, and their mixes as substitutes for peat were evaluated regarding their recommendation for potting media.
The mixes with a maximum of 50% of vermicompost or green compost had acceptable air filled porosity (AFP) and easily available water (EAW). In the vermicompost the level of organic matter (OM), dry bulk density (DBD) and shrinkage were acceptable; however, the AFP and EAW together were not at the recommended level in the different batches; as a consequence, vermicompost should not be used alone for potting media.
In the green compost, the level of OM was low which increased the DBD and consequently the AFP was diminished.
The particle size distribution (PSD) was different among peat, vermicompost and green compost.
The coarse peat had the lower proportion of particles from 0.25 to 2.00 mm (41%) whereas the green compost had the lower coarseness index (CI: percentage by weight of particles larger than 0.5 mm in diameter), 48.4%. The direct effect of the PSD, OM and DBD in the water and air availability was confirmed.
Moreover, there were high correlations between the OM, DBD, shrinkage, pore volume and PSD with the water release curve.
Those properties should be considered in order to increase the level of substitution of vermicompost in peat-based potting media.
The mixes with a maximum of 50% of vermicompost or green compost had acceptable air filled porosity (AFP) and easily available water (EAW). In the vermicompost the level of organic matter (OM), dry bulk density (DBD) and shrinkage were acceptable; however, the AFP and EAW together were not at the recommended level in the different batches; as a consequence, vermicompost should not be used alone for potting media.
In the green compost, the level of OM was low which increased the DBD and consequently the AFP was diminished.
The particle size distribution (PSD) was different among peat, vermicompost and green compost.
The coarse peat had the lower proportion of particles from 0.25 to 2.00 mm (41%) whereas the green compost had the lower coarseness index (CI: percentage by weight of particles larger than 0.5 mm in diameter), 48.4%. The direct effect of the PSD, OM and DBD in the water and air availability was confirmed.
Moreover, there were high correlations between the OM, DBD, shrinkage, pore volume and PSD with the water release curve.
Those properties should be considered in order to increase the level of substitution of vermicompost in peat-based potting media.
Publication
Authors
L. Campos Mota, U. van Meeteren, C. Blok
Keywords
vermicompost, green compost, physical properties, air filled porosity, easily available water
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