Compost based ecological growing media according EU eco-label requirements

Abstract

Green compost is seen as one of the best solutions for peat replacement in growing media and for increasing their sustainability. However, the poor quality of many composts has restricted their use as substrate components. The EU Ecolabel may be awarded to products and services that have a reduced environmental impact throughout their life cycle. It is voluntary and ensures certain aspects of the origin and quality. The primary aim of this work was to obtain a gorse compost-based substrate fulfilling the requirements for award of the eco-label. Forest biomass consisting mainly of gorse was composted in dynamic piles with or without irrigation (I) at the beginning and with or without addition of 5% v/v poultry manure (PM). There were thus four different composting treatments that were designated PM0I, PM5I, PM5 and PM0. Temperature, moisture, pH and the C/N ratio of the composting biomass were monitored over a period of nearly 10 months. The resulting composts were characterized in physical, chemical and biological terms, and evaluated for compliance with the requirements of the European Union eco-label for growing media. All composts were found to be mature, stable and pathogen-free. All of them were suitable for use as growing media, exhibiting a high aeration and drainage capacity, little water retention and adequate level of available nutrients. In general they also met the requirements of the EU eco-label, although not all were weed seed-free, which was possibly the sole unfulfilled EU eco-label requirement.El compost verde se considera como una de las mejores soluciones para el reemplazo de turba en medios de cultivo y así aumentar su sostenibilidad. Sin embargo, la mala calidad de muchos composts ha restringido su uso como componentes de sustrato. La etiqueta ecológica de la UE podrá concederse a productos y servicios que tengan un impacto medioambiental reducido a lo largo de su ciclo de vida. Es voluntario y garantiza ciertos aspectos del origen y la calidad. El objetivo principal de este trabajo era obtener un sustrato a base de compost de tojo que cumpliera los requisitos para la concesión de la etiqueta ecológica. La biomasa forestal constituida principalmente por tojo se compostó en pilas dinámicas con o sin riego (I) al principio y con o sin adición de 5% de gallinaza (PM). Por tanto, hubo cuatro tratamientos de compostaje diferentes designados PM0I, PM5I, PM5 y PM0. La temperatura, la humedad, el pH y la relación C/N de la biomasa de compostaje se controlaron durante un período de casi 10 meses. Los composts resultantes se caracterizaron física, química y biológicamente y se evaluaron para el cumplimiento de los requisitos de la etiqueta ecológica de la Unión Europea para medios de cultivo. Se encontró que todos los composts estaban maduros, eran estables y libres de patógenos. Todos ellos fueron adecuados para su uso como medios de cultivo, exhibiendo una alta capacidad de aireación y drenaje, poca retención de agua y un nivel adecuado de nutrientes disponibles. En general, también cumplían los requisitos de la etiqueta ecológica de la UE, aunque no todos estaban libres de malas hierbas, que posiblemente era el único requisito no cumplido de la etiqueta ecológica de la UE