Desarrollo de nuevos sustratos a base de compost y biochar para la propagación y producción de Rosmarinus officinalis L. en vivero profesional

Abstract

[ES] Entre los sistemas de producción de biocombustibles se encuentra la carbonización de materia orgánica mediante pirólisis. El biochar es un subproducto de la pirólisis. La propuesta más extendida de valorización y reutilización del biochar es como enmienda orgánica del suelo. También existen iniciativas de uso de biochar como material estructurante en las mezclas para compostaje. El compost resultante no ha sido probado aún como sustrato o componente de sustrato en cultivo en contenedor. Por ello planteamos como objetivo de este TFG la evaluación agronómica de un compost producido con mezcla de gallinaza y biochar y su comparación con un compost de gallinaza y con el biochar sin compostar. Se caracterizarán los materiales de partida y los sustratos preparados con mezclas de estos materiales y turba, y se cultivará romero en estas mezclas, analizando el efecto del sustrato en el crecimiento y producción de esta planta.

[EN] Composting as a means to reclaim organic waste has been widely studied in the recent years. The product of composting or compost is used in agriculture as organic soil amendment or as substrate constituent for containerized plant growth. In the latter case it has been shown of special interest as peat substitute. Biochar is obtained by pyrolysis of green material at low oxygen concentration and it is being proposed as soil amendment in agriculture for its stability and for the fact that it can sequester greenhouse-effect gases. The aim of this work is to assess two composts and a biochar as substrate constituents: one compost from poultry manure, another from poultry manure co-composted with biochar from oak pruning waste and the biochar from the same batch that had been used in the co-composting process. The plant chosen for the assessment was the Mediterranean Rosmarinus officinalis L. The poultry manure compost, the poultry manure compost co-composted with biochar, the biochar and Sphagnum peat were mixed at different proportions. The physical, physicochemical, chemical and biological properties of the mixes were determined, focusing on those of interest for containerized plant growth. Finally the agronomical assessment of the materials was carried out by growing rosemary in a nursery. Two assays were performed: cutting rooting and plant growth. Results showed that the properties of both composts did not largely differ. Mixing the poultry manure compost with biochar improved physical properties such as air volume and shrinkage, however for the improvement of other properties large proportions of peat were needed in the mix. Biochar, as opposed to both composts, was not phytotoxic at high concentrations and showed the ability to sequester atmospheric CO2. Substrates with low compost proportion increased plant growth with respect to those containing pure peat. Besides, biochar improved cutting rooting with respect to peat, which might indicate that it contained growth stimulators.