Articles
EVALUATION OF COMPOSTED PINE BARK AND CAROB PODS AS COMPONENTS FOR HORTICULTURAL SUBSTRATES
In this work pine bark and carob pods where studied to evaluate their use as horticultural substrates in the culture of Pelargonium x hortorum cv. ‘Meridonna’.
Both products were previously composted in order to improve their physical properties, the materials being characterized before and after the composting process.
During this process, the stabilization of organic matter was denoted by the increase of non hydrolyzable nitrogen and cation exchange capacity.
In carob pods, it was pointed out that carbon/nitrogen ratio is a weak compost maturity indicator.
There was a reduction of air capacity and an increase in easily available water content and buffering capacity, related to the change in particles size.
Some phytotoxic effect was still detected in the final materials.
Mixes of these materials with sphagnum peat where prepared.
Geraniums growth was restricted on carob pods (100%). All the other mixes gave a similar performance.
Only one compost (1:3 pine bark-sludge:peat) gave better growth (11% in fresh weight and 10% in dry weight) than the control (Triohum Traysubstrat compost), but this response was not significant.
This fact could be attributed to its excellent balance of air capacity and easily available water content.
The result indicates that locally available pine bark (from 25 to 100%) and carob pods (from 25 to 75%), can be used as components of peat based composts, for ornamental pot plant production with "ebb and flood" irrigation.