Articles
THE USE OF COMPOSTED GREEN WASTE (CGW) AS A GROWING MEDIUM COMPONENT
Article number
549_11
Pages
107 – 114
Language
English
Abstract
Green waste is an increasing resource in Ireland as more biodegradable material is diverted from landfill.
Using it as a part substitute for peat in a growing medium would be economically attractive and would help to conserve finite peat resources.
The effect of adding composted green waste (CGW) to a peat growing medium on the chemical and physical properties of the medium and on plant performance was studied.
Addition of CGW increased bulk density and reduced pore space.
Rates of up to 20% of volume had only small effects on the physical properties but a further increase up to 50% reduced the easily available water content.
Adding CGW consistently increased the pH of the growing medium.
In the first experiment, a rate of 50% CGW did not adversely affect early growth of tomato seedlings but reduced subsequent growth which was linked to decreased availability of N. In a second experiment where three CGWs were included a 50% rate gave a slight reduction in early growth in the case of two of the materials and a sharper reduction with the third material.
This early growth reduction was associated with high K levels.
Subsequent growth was limited by the available N content.
Reduced N availability was associated with high rates of CGW in the growing medium.
It was concluded that a rate of 20% CGW could be included without adversely affecting plant performance.
Using it as a part substitute for peat in a growing medium would be economically attractive and would help to conserve finite peat resources.
The effect of adding composted green waste (CGW) to a peat growing medium on the chemical and physical properties of the medium and on plant performance was studied.
Addition of CGW increased bulk density and reduced pore space.
Rates of up to 20% of volume had only small effects on the physical properties but a further increase up to 50% reduced the easily available water content.
Adding CGW consistently increased the pH of the growing medium.
In the first experiment, a rate of 50% CGW did not adversely affect early growth of tomato seedlings but reduced subsequent growth which was linked to decreased availability of N. In a second experiment where three CGWs were included a 50% rate gave a slight reduction in early growth in the case of two of the materials and a sharper reduction with the third material.
This early growth reduction was associated with high K levels.
Subsequent growth was limited by the available N content.
Reduced N availability was associated with high rates of CGW in the growing medium.
It was concluded that a rate of 20% CGW could be included without adversely affecting plant performance.
Authors
M. Prasad, M.J. Maher
Keywords
electrical conductivity, nitrogen, nutrient availability, tomato, Lycopersicon esculentum
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