Articles
THE USE OF GREEN COMPOST IN THE PRODUCTION OF CONTAINER NURSERY STOCK IN THE UK: CHALLENGES AND OPPORTUNITIES
Article number
819_2
Pages
27 – 32
Language
English
Abstract
A comprehensive programme of 29 trials involving container nursery stock has been carried out on 25 nurseries using 267 subjects to assess the use of green compost in peat-free and peat-reduced growing media.
The trials encompassed diverse geographic locations, potting methods, irrigation systems, environments (outdoor, glasshouse and polythene tunnel) and end-markets (retail and landscape). Seven green composts were used, all accredited to the UK PAS 100 standard.
Green compost was usually incorporated into growing media at 33% v/v.
Apart from nitrogen, the green compost provided all base nutrients and the usual, controlled-release fertiliser was added to all treatments.
All trials used a peat-based medium as control.
The main trends are summarised as follows:
The trials encompassed diverse geographic locations, potting methods, irrigation systems, environments (outdoor, glasshouse and polythene tunnel) and end-markets (retail and landscape). Seven green composts were used, all accredited to the UK PAS 100 standard.
Green compost was usually incorporated into growing media at 33% v/v.
Apart from nitrogen, the green compost provided all base nutrients and the usual, controlled-release fertiliser was added to all treatments.
All trials used a peat-based medium as control.
The main trends are summarised as follows:
- Despite bulk density of the peat-free medium being 30-50% higher than the peat-based medium, handling properties were acceptable (manual and machine-aided potting). Furthermore, the difference was reduced at potting (peat-free, for example, compressed less) and reduced further on watering.
- Where growth of liverwort or moss occurred on the surface of peat-based media, it was frequently suppressed in peat-free and peat-reduced media.
- Reduction in foliar disease (notably, Xanthomonas hederae) was seen in a few crops raised in peat-free media.
- No slumping or N starvation was observed.
- All plants raised in peat-free and peat-reduced media were marketable.
- Internodes were sometimes shorter in plants raised in peat-free and peat-reduced media (often welcomed by the grower).
- Despite the absence of wetting agent, peat-free and peat-reduced media retained water well, whether applied by overhead means (spray lines), trickle nozzles or capillary methods (sand bed or matting).
- Peat-free mixes seemed to require slightly more frequent irrigation but used no more water overall.
Experience suggests that good quality green compost can be a cost-effective part alternative to peat in growing media for container nursery stock.
Publication
Authors
A. Rainbow
Keywords
peat-free, growing media, bulk density, liverwort, CAT extraction, handling, disease suppression
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