[en] To study the process of composting of grape marc and test the resulting compost as a substrate for the cultivation of ornamental plants, six composting processes, with mixtures of dealcoholised grapevine marc and grape stalk (DM+GS) in a 1:1 ratio (v:v), were carried out in Seville (Spain) between 2000 and 2006. The duration of the composting ranged between 20 and 24 weeks in the Spring-Summer season. Weekly, temperature, pH, EC, N-NO3- and N-NH4+, were measured. The maximum temperatures reached values of 65-73°C at a depth between 40 and 80 cm. The compost had a slightly alkaline pH, slightly salinity, high organic matter and total nitrogen contents. The final compost chemical composition in total elements showed values in the same range as those corresponding to plant material, except for Fe. The distribution in the size of the particles gives way to a total porous space that is close to the one considered as optimal in a substrate for soilless cropping. Pore size distribution showed a prevalence of big pores that produces unbalance in the water-air ratios, resulting in a material with a good aeration but with low water retention. The composts were tested as substrates for four ornamental species: geranium, petunia, carnation and gerbera. The results suggest that compost has no limiting characteristics for its use as a medium for the cultivation of ornamental plants in container, and can replace conventional substrates, such as peat and coconut fibre.

[es] Para estudiar el proceso de compostaje de orujos de uva y probar el compost resultante como sustrato para el cultivo de plantas ornamentales, se llevaron a cabo, en Sevilla (Espa&ntilde;a) entre 2000 y 2006, seis procesos de compostaje, con mezclas de orujos de vid desalcoholizados y tallos de vid o rasp&oacute;n (DM + GS) en una proporci&oacute;n 1:1 (v:v). La duraci&oacute;n del compostaje oscil&oacute; entre 20 y 24 semanas en el per&iacute;odo de primavera-verano. Se midieron semanalmente temperatura, pH, CE, N-NO3- y N-NH4+. Se alcanzaron temperaturas m&aacute;ximas de 65 a 73&deg;C a 40-80 cm de profundidad. El compost resultante ten&iacute;a pH ligeramente alcalino, moderada salinidad, altos contenidos en materia org&aacute;nica y nitr&oacute;geno total. Los an&aacute;lisis qu&iacute;micos del compost mostraron niveles de elementos totales en igual rango que los correspondientes a material vegetal, excepto Fe. La distribuci&oacute;n del tama&ntilde;o de part&iacute;culas del material origina un espacio poroso total cercano al considerado &oacute;ptimo en los sustratos para cultivo sin suelo. La distribuci&oacute;n del tama&ntilde;o de poros mostr&oacute; una prevalencia de poros grandes, circunstancia que produce un desequilibrio en las relaciones aire-agua, dando como resultado un material con buena aireaci&oacute;n, pero con baja retenci&oacute;n de agua. Los composts se probaron como sustratos para cuatro especies ornamentales: geranio, petunia, clavel y gerbera. Los resultados no sugieren ninguna caracter&iacute;stica limitante para el uso del compost como medio para el cultivo de plantas ornamentales en contenedor, y puede sustituir a los sustratos convencionales como la turba y la fibra de coco.